NSKW Installation Manual

NSKW 06 to 17 kW
Geothermal Hydronic Heat Pump - 50 Hz

Installation Information

Water Piping Connections

Electrical Data

Startup Procedures

Preventive Maintenance

IM1066WN 03/16
 NSKW INSTALLATION MANUAL

Table of Contents
Model Nomenclature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

BS EN 14511-2 Performance Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Energy Labelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

General Installation Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .6

Dimensional Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Physical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Water Quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Field Connected Water Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9-10

Potable Water Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12

Hydronic Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Accessories and Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16-17

Wiring Schematics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18-21

Heat Pump Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

External Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23-24

Converting to a Dedicated Cooling Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

Unit Startup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Standard Board - Control Features. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27-28

Standard Control - Panel Configuration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29-30

Optional Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31-35

Reference Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Pressure Drop. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Operating Limits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36

Flow Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Thermistor Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37

Operating Parameters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38

Antifreeze Correction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Troubleshooting Guideline for Refrigerant Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Heating and Cooling Cycle Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Startup and Troubleshooting Form . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42

Troubleshooting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43-44

Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

Service Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Technical Documentation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

NSKW INSTALLATION MANUAL

Model Nomenclature
1-4 5-6 7 8 9 10 11 12 13-14 15
NSKW 08 R 6 0 2 C C SS A

Model Vintage
NSKW = Envision Series 50Hz A = 08-17
Hydronic Heat Pump B = 06

Capacity (kW Output) Future Option

06 SS = Standard Option
08
12 Load Coax 1
17 C = Copper
N = Cupronickel
Operation
H = Heating Only Source Coax
R = Reversible C = Copper
N = Cupronickel
Voltage
6 = 220-240/50/1 Controls Option
7 = 380-420/50/3 2 = Standard Board
4 = FX10 without communication
Hot Water Option 5 = FX10 with Open N2 Com Card
0 = No Hot Water Generation, No IntelliStart 6 = FX10 with LonWorks card Com Card
2 = Hot Water Generation, No IntelliStart (12-17) 7 = FX10 with BACnet Com card
3 = No Hot Water Generation, IntelliStart 8 = FX10 without communication, with User Interface
5 = Hot Water Generation, IntelliStart (12-17) 9 = FX10 with Open N2 Com Card, with User Interface
0 = FX10 with Lonworks Com card, with User Interface
3 = FX10 with BACnet Com card, with User Interface

NOTES: Hot Water Generation (HWG) only available on NSKW12-17 and requires a field installed external pump
1
- 06 heating only models are available only with copper double wall vented load coax.

Energy Labelling
Supplier WaterFurnace International, Inc.
Model NSKW06 NSKW08 NSKW12 NSKW17
Model hot water heater - - - -
Temperature application °C 35 55 35 55 35 55 35 55
Declared load profile for water heating - - - -
Seasonal space heating energy efficiency class, average climate A++ A++ A++ A++ A++ A++ A++ A++
Water heating energy efficiency class, average climate - - - -
Rated heat output (Pdesignh), average climate kW 6 8 12 17
Annual energy consumption space heating, average climate kWh 2,860 3,432 3,689 4,543 4,920 6,343 7,985 9,656
Annual energy consumption water heating, average climate kWh - - - -
Seasonal space heating energy efficiency, average climate % 160 119 178 132 187 137 164 126
Water heating energy efficiency, average climate % - - - -
Sound power level LWA indoors dB 57 57 61 63
Rated heat output (Pdesignh), cold climate kW 6 8 12 17
Rated heat output (Pdesignh), warm climate kW 6 8 12 17
Sound power level LWA outdoors dB dB - - - -
3/18/2016

All Envision Series NSKW product is safety tested to CE standards and

performance tested in accordance with standard BS EN 14511-2.

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 NSKW INSTALLATION MANUAL

BS EN 14511-2 Performance Ratings

Heating Performance
B0/W35 W10/W35 B0/W45 B5/W35 W10/W45

Model Capacity Power Capacity Power Capacity Power Capacity Power Capacity Power
Output COP Input Output COP Input Output COP Input Output COP Input Output COP Input
kW kW kW kW kW kW kW kW kW kW

06 5.80 3.80 1.53 7.30 4.80 1.52 5.50 2.90 1.90 6.60 4.30 1.54 7.10 3.70 1.92
08 8.30 4.20 1.98 10.6 5.30 2.00 8.00 3.20 2.50 9.50 4.80 1.98 10.2 4.10 2.49
12 11.6 4.20 2.80 14.4 5.30 2.72 11.3 3.20 3.53 13.3 4.80 2.77 14.2 4.10 3.46
17 16.6 3.70 4.49 21.4 4.70 4.55 15.9 2.90 5.50 19.0 4.30 4.42 20.4 3.70 5.51
All ratings based upon 220V operation 9/26/11
All ratings based on new heat pump with clean heat exchangers

Cooling Performance
W30/B0 W30/W12 W30/W23
Model Capacity Power Input Capacity Power Input Capacity Power Input
EER (W/W) EER (W/W) EER (W/W)
Output kW kW Output kW kW Output kW kW
06 4.00 2.80 1.43 5.90 4.10 1.44 8.10 5.60 1.45
08 6.10 3.00 2.03 9.00 4.40 2.05 12.4 6.00 2.07
12 8.20 2.90 2.82 12.0 4.30 2.80 16.6 5.80 2.86
17 11.2 2.60 4.30 16.4 3.80 4.32 22.7 5.20 4.37
All ratings based upon 220V operation 9/26/11
All ratings based on new heat pump with clean heat exchangers

Legend
ABBREVIATIONS AND DEFINITIONS:
COP = coefficient of performance L/s = liters per second
EER = cooling energy efficiency (TC/kW) LLT = leaving load fluid temperature from heat pump
ELT = entering load fluid temperature LRA = locked rotor amps (starting current)
EST = entering source fluid temperature to heat pump LST = leaving source fluid temperature from heat pump
FLA = full load amps LWPD= load heat exchanger water pressure drop
FtHd = pressure drop in feet of head MCC = maximum continuous current
gpm = US gallon per minute PD = pressure drop
HC = heating capacity in kW psi = pressure drop in pounds per square inch
HE = heat of extraction in kW P/T = Pressure/Temperature
HR = heat rejected in kW RLA = run load amps
kPa = kilopascal TC = total cooling capacity in kW
kW = kilowatt W = Watt

CONVERSIONS:
x°F = (x - 32)/1.8°C 1 US Gallon = 3.785412 L
1 bar = 100 kPa 1 Btu/h = 0.29037 W
1 gpm = 0.0631 L/s

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NSKW INSTALLATION MANUAL

General Installation Information

Safety Considerations WARNING: To avoid equipment damage, do not
leave the system filled in a building without heat
Installing and servicing air conditioning and heating
during cold weather, unless adequate freeze
equipment can be hazardous due to system pressure and
protection levels of antifreeze are used. Heat
electrical components. Only trained and qualified service
exchangers do not fully drain and will freeze
personnel should install, repair or service heating and air
unless protected, causing permanent damage.
conditioning equipment. When working on heating and
air conditioning equipment, observe precautions in the
literature, tags and labels attached to the unit and other Unit Location
safety precautions that may apply. Provide sufficient room to make water and electrical
connections. If the unit is located in a confined space,
Follow all safety codes. Wear safety glasses and work provisions must be made for unit servicing. Locate the
gloves. Use quenching cloth for brazing operations. Have unit in an indoor area that allows easy removal of the
fire extinguisher available for all brazing operations. access panels and has enough space for service personnel
to perform maintenance or repair. These units are not
NOTE: Before installing, check voltage of unit(s) to ensure approved for outdoor installation and, therefore, must be
proper voltage. installed inside the structure being conditioned. Do not
locate units in areas subject to freezing conditions.
WARNING: Before performing service or
maintenance operations on the system, turn off WARNING: Do not store or install units in
main power switches to the unit. Electrical shock corrosive environments or in locations subject
could cause serious personal injury. to temperature or humidity extremes (e.g. attics,
garages, rooftops, etc.). Corrosive conditions and
Process Water Applications high temperature or humidity can significantly
reduce performance, reliability, and service life.
For process water applications, it is recommended that
a secondary load heat exchanger be installed to prevent
corrosion to the unit’s primary coaxial coil. In situations Mounting Units
where scaling could be heavy or where biological growth Units should be mounted level on a vibration absorbing pad
such as iron bacteria will be present, a closed loop system slightly larger than the base to provide isolation between
is recommended. Over a period of time, ground water unit the unit and the floor. It is not necessary to anchor the unit
heat exchanger coils may lose heat exchange capability to the floor. Allow access to the front, back, and side access
due to a buildup of mineral deposits. These can be cleaned panels for servicing.
only by a qualified service mechanic as special pumping
equipment and solutions are required.

Moving and Storage

Move units in the normal “Up” orientation as indicated by
the labels on the unit packaging. When the equipment
is received, all items should be carefully checked against
the bill of lading to ensure that all crates and cartons
have been received in good condition. Examine units for
shipping damage, removing unit packaging if necessary
to properly inspect unit. Units in question should also
be internally inspected. If any damage is observed, the
carrier should make the proper notation on delivery receipt
acknowledging the damage. Units are to be stored in a
location that provides adequate protection from dirt, debris
and moisture.

DWP`ObW]\>OR;]c\bW\U

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 NSKW INSTALLATION MANUAL

Dimensional Data

S T
N Q
R P

B I
E H
G
Z U L J
W K

D F
Y X V
M O

NOTE:
NOTE:Plastic
Plasticfront panel
front extends
panel 3.56
extends 1.4"cm beyond
(3.56 cm) front of cabinet.
beyond front of cabinet. 8/09/13

Electrical Knockouts
Overall Cabinet Water Connections
J K L
1/2 in. 3/4 in. 3/4 in.
A B C D E F G H I
Model cond cond cond
Load Load Source Source Load Source HWG
HWG Low Ext Power
Depth Height Width Liquid Liquid Liquid Liquid HWG In Water Water Water
Out Voltage Pump Supply
In Out In Out FPT FPT FPT
06 cm. 59.7 66.3 49.5 25.4 56.4 25.4 56.4 - - 25.4 mm 25.4 mm - 40.6 36.1 36.1
08 cm. 78.7 66.5 55.9 5.3 49.8 5.3 49.8 60.7 60.7 25.4 mm 25.4 mm 12.7 mm 43.4 37.6 43.4
12 cm. 78.7 66.5 55.9 5.6 52.3 5.6 52.3 60.7 60.7 31.8 mm 31.8 mm 12.7 mm 43.4 37.6 43.4
17 cm. 78.7 66.5 55.9 6.1 58.4 6.1 58.4 52.3 52.3 31.8 mm 31.8 mm 12.7 mm 43.4 37.6 43.4

Water Connections Electrical Knockouts

M N O P Q R S T U V W X Y Z
Model Load Source Side Side
Load Source HWG Power Low Ext Ext Power Power
Liquid Liquid HWG In Power Power
Liquid In Liquid In Out Supply Voltage Pump Pump Supply Supply
Out Out Supply Supply
06 cm. 6.1 6.1 6.1 6.1 - - 8.9 7.4 37.8 6.6 5.3 4.4 7.4 10.4
08 cm. 4.1 7.0 7.0 4.1 5.1 4.6 12.2 12.2 43.4 7.0 37.8 12.2 12.2 43.4
12 cm. 4.6 9.1 9.1 4.6 5.3 4.6 12.2 12.2 43.4 7.1 37.8 12.2 12.2 43.4
17 cm. 4.6 10.2 10.2 4.6 10.7 3.6 12.2 12.2 43.4 7.1 37.8 12.2 12.2 43.4
8/6/10
NOTE: Plastic front panel extends 3.56 cm beyond front of cabinet.

Physical Data
Model 06 08 12 17
Compressor (1 each) Scroll
Factory Charge R410A, oz [kg] 58 [1.64] 70 [1.98] 68 [1.93] 110 [3.12]
Coax & Piping Water Volume - gal [l]* 0.89 [3.38] 1.0 [3.94] 1.4 [5.25] 1.6 [6.13]
Weight - Operating, lb [kg] 225 [102.1] 290 [131.5] 325 [147.4] 345 [156.5]
Weight - Packaged, lb [kg] 247 [112.0] 305 [138.3] 340 [154.2] 360 [163.3]
Note: * Source or load side only 3/25/15

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NSKW INSTALLATION MANUAL

Water Quality
General building’s piping system that the designer may need to take
into consideration when deciding the parameters of the
NSKW heat pumps may be successfully applied in a wide
water quality.
range of residential and light commercial applications. It
is the responsibility of the system designer and installing
If an antifreeze or water treatment solution is to be used,
contractor to ensure that acceptable water quality is
the designer should confirm it does not have a detrimental
present and that all applicable codes have been met in
effect on the materials in the system.
these installations. Failure to adhere to the guidelines in the
water quality table could result in loss of warranty.
Contaminated Water
Water Treatment In applications where the water quality cannot be held to
prescribed limits, the use of a secondary or intermediate
Do not use untreated or improperly treated water.
heat exchanger is recommended to separate the unit from
Equipment damage may occur. The use of improperly
the contaminated water.
treated or untreated water in this equipment may result in
scaling, erosion, corrosion, algae or slime. The services of a
The following table outlines the water quality guidelines
qualified water treatment specialist should be engaged to
for unit heat exchangers. If these conditions are exceeded,
determine what treatment, if any, is required. The product
a secondary heat exchanger is required. Failure to supply
warranty specifically excludes liability for corrosion,
a secondary heat exchanger where needed will result in a
erosion or deterioration of equipment.
warranty exclusion for primary heat exchanger corrosion or
failure.
The heat exchangers and water lines in the units are copper
or cupronickel tube. There may be other materials in the

Water Quality Guidelines

Material Copper 90/10 Cupronickel 316 Stainless Steel
pH Acidity/Alkalinity 7-9 7-9 7-9
Calcium and (Total Hardness) (Total Hardness) (Total Hardness)
Scaling
Magnesium Carbonate less than 350 ppm less than 350 ppm less than 350 ppm
Less than 0.5 ppm (rotten egg
Hydrogen Sulfide 10 - 50 ppm Less than 1 ppm
smell appears at 0.5 ppm)
Sulfates Less than 125 ppm Less than 125 ppm Less than 200 ppm
Chlorine Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Chlorides Less than 20 ppm Less than 125 ppm Less than 300 ppm
Carbon Dioxide Less than 50 ppm 10 - 50 ppm 10 - 50 ppm
Corrosion Ammonia Less than 2 ppm Less than 2 ppm Less than 20 ppm
Ammonia Chloride Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Ammonia Nitrate Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Ammonia Hydroxide Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Ammonia Sulfate Less than 0.5 ppm Less than 0.5 ppm Less than 0.5 ppm
Total Dissolved Solids (TDS) Less than 1000 ppm 1000 - 1500 ppm 1000 - 1500 ppm
LSI Index +0.5 to -0.5 +0.5 to -0.5 +0.5 to -0.5
Iron, FE2+ (Ferrous)
< 0.2 ppm < 0.2 ppm < 0.2 ppm
Iron Fouling Bacterial Iron Potential
(Biological Growth) Less than 1 ppm, above this Less than 1 ppm, above this Less than 1 ppm, above this
Iron Oxide
level deposition will occur level deposition will occur level deposition will occur
Less than 10 ppm and filtered Less than 10 ppm and filtered Less than 10 ppm and filtered
Suspended Solids
for max. of 600 micron size for max. of 600 micron size for max. of 600 micron size
Erosion
Threshold Velocity
< 1.8 m/sec < 1.8 m/sec < 1.8 m/sec
(Fresh Water)
NOTES: Grains = ppm divided by 17 2/22/12
mg/L is equivalent to ppm

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 NSKW INSTALLATION MANUAL

Field Connected Water Piping

General to determine the flow rate. These ports should be located
Each unit is equipped with captive female pipe thread (FPT) adjacent to the supply and return connections on the unit.
water connections to eliminate ‘egg-shaping’ from use of The proper flow rate cannot be accurately set without
a backup wrench. For making the water connections to measuring the water pressure drop through the refrigerant-
the unit, a Teflon tape thread sealant is recommended to to-water heat exchanger (See Pressure Drop Table for water
minimize internal fouling of the piping. Do not over tighten flow and pressure drop information). Normally about 0.054
connections. All supply and return water piping should be L/s per kW flow rate of cooling capacity (0.040 L/s per kW
insulated to prevent excess condensation from forming on minimum) is needed. Both source as well as load fluid piping
the water lines. must be at least as large as the unit connections on the heat
pump (larger on long runs).
NOTES: 1) WaterFurnace recommends a male national pipe
thread (NPT) to British standard pipe fitting (BSPF) to Never use flexible hoses of a smaller inside diameter than that
adapt to NSKW water connections. 2) Units are factory run- of the water connection on the unit and limit hose length to
tested using propylene glycol. Prior to connecting piping 3.05 m per connection. Check carefully for water leaks.
to unit, thoroughly flush heat exchangers.
CAUTION: Water piping exposed to outside
The piping installation should provide service personnel with temperature may be subject to freezing.
the ability to measure water temperatures and pressures.
The water lines should be routed so as not to interfere with Open Loop Well Water Systems
access to the unit. The use of a short length of high pressure Always maintain water pressure in the heat exchanger by
hose with a swivel type fitting may simplify the connections placing water control valves at the outlet of the unit. Use
and prevent vibration. Optional stainless steel hose kits are a closed bladder type expansion tank to minimize mineral
available as an accessory item. deposits. Ensure proper water flow through the unit by
checking pressure drop across the heat exchanger and
Before final connection to the unit, the supply and return comparing it to the figures in the pressure drop table.
hose kits must be connected, and the system flushed Normally, about 0.038 L/s per kW flow rate of cooling
to remove dirt, piping chips and other foreign material. capacity is needed in open loop systems, 0.029 L/s per kW
Normally, a combination balancing and close-off (ball) valve minimum if entering source temperature is above 10°C.
is installed at the return, and a rated gate or ball valve is
installed at the supply. The return valve can be adjusted to Some water control valves draw their power directly from
obtain the proper water flow. The valves allow the unit to be the unit’s 24V transformer and can overload and possibly
removed for servicing. burn out the transformer. Check total VA draw of the water
valve(s) and ensure it is under 40 VA.
The proper water flow must be delivered to each unit
whenever the unit heats or cools. To assure proper flow, Discharge water from a heat pump can be disposed of in
the use of pressure/temperature ports is recommended various ways depending on local building codes (i.e. recharge

Typical Open Loop Installation

Rubber Bladder
Expansion Tank

Flow Regulator Valve

Line Voltage Shut-off Valve
Disconnect (to isolate solenoid Solenoid
valve while acid Valve Water Out
flushing)

Water In

Boiler Drains for Shut-off

HX Flushing Valve
P/T Plugs

Load Liquid Vibration Absorbing NOTE: Valves and boiler drains must be installed
Connections Mesh or Air Pad so the heat exchanger can be acid flushed.

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NSKW INSTALLATION MANUAL

Field Connected Water Piping cont.

well, storm sewer, drain field, adjacent stream or pond, Typical Closed Loop Earth Coupled Installation
etc.). Most local codes restrict the use of sanitary sewer for
disposal. Consult your local building and zoning departments
to ensure compliance in your area.
Earth Coupled Loop
Piping with Insulation
Earth Coupled Systems with Flow Center
Once piping is completed between the unit, flow center Line Voltage
Disconnect
and the earth loop, final purging and charging of the loop is
needed. A pump capable of 14 m3/hr @ 25 meters of head Unit Connector Kits
with Insulation
is needed to achieve adequate flow velocity in the loop to
purge air and dirt particles from the loop itself. Antifreeze
solution is used in most areas to prevent freezing. Maintain
the pH in the 7.6-8.2 range for final charging.

Flush the system adequately to remove as much air as

possible. Then, pressurize the loop to a static pressure of P/T Plugs
345-517 kPa. This is normally adequate for good system
Vibration Absorbing
Load Liquid
operation. Ensure that the flow center provides adequate Connections
Mesh or Air Pad

flow through the unit by checking pressure drop across the

heat exchanger and by comparing it to the figures shown
in the Pressure Drop tables. Usually, 0.054 L/s per kW or
minimum 0.040 L/s per kW of cooling capacity is needed in
closed loop earth-coupled applications. GeoLinkTM Design Studio (GDS) or another commercial
software package. Installers shall follow the guidelines
detailed in Microgeneration Certification Scheme (MCS)
Ground Loop Design and Installation Installation Standard MIS 3005 for designing ground loop
This instruction manual does not cover the design and collectors. Additional guidance on ground collectors is
installation of the ground loop system. WaterFurnace provided by International Ground-Source Heat Pump
recommends that all ground loops are designed using Association (IGSHPA).

Potable Water Systems

NSKW06-17 kW heat pumps can be equipped with a Hot Water Generator Connections
double-wall vented coaxial heat exchanger capable of hot The heat reclaiming hot water generator coil is vented double-
water generation (HWG). An optional factory-installed hot wall copper construction and is suitable for potable water. To
water generator coil may be provided with NSKW08-17. The maximize the benefits of the hot water generator a minimum
temperature of the hot water produced by the heat pump 50-gallon water heater is recommended. For higher demand
cannot be adjusted and will vary with the inlet temperature. applications, use an 80-gallon water heater as shown below or
WaterFurnace recommends the use of a properly sized two 50-gallon water heaters connected in a series. A geo storage
buffer tank equipped with supplemental electric immersion tank should not be used in this application unless it is plumbed
heaters in conjunction with all NSKW models used in an in a series with an electric water heater. The geo storage tank is
HWG application. Immersion heaters must be capable equipped with a single 4500 Watt element and will not be able
of heating the water to 60°C at a regular time interval to provide adequate water heating if used as a standalone water
to prevent the build-up of bacteria such as Legionella. heater. Electric water heaters are recommended. Make sure all
Installations must meet minimum requirements outlined in local electrical and plumbing codes are met for installing a hot
UK Domestic Heating Compliance Guide. water generator. The Envision NSKW is not supplied with an
internal circulator.
CAUTION: Hot water in excess of 60°C can cause
scalding.

10
 NSKW INSTALLATION MANUAL

Potable Water Systems cont.

Suggested Domestic Water Heater Hookup
207 kPa Pressure
RELIEF VALVE Gauge
Air
Vent
LOAD PUMP

HYDRONIC Vent Valve or

Air LOAD P/T Port**
Separator
Back Flow Preventer / Expansion
Pressure Relief Valve Tank

Dielectric HOT COLD

Unions (Piped in
series to
an electric
water heater)
GEO PUMP
STORAGE
TANK DOMESTIC
Dip Tube
FROM TO
HWG HWG

Source OUT

Dielectric
Unions P/T P/T
Ports Ports

Ball Valve
Ball Valve
Source IN
NOTES: WaterFurnace
* A 207 kPa pressure relief valve (Part No: SRV30) should be used in
hydronic applications. NSKW Series
** Vent valve or Pressure/Temperature port at highest point in return line prior to ball valve.

NOTES:
1) Unions and valves must be installed so that acid flushing
of the heat exchanger is possible.
2) Route thermistor wires to NSKW. Remove yellow
thermistor wires on TB 3 and 4 from control box and
connect thermistor wires from geothermal storage tank.
Set the pump sampling (PS) in the set up of the control
board to continuously (C) sampling (reference Note 5 in
the Wiring Schematic).

11
NSKW INSTALLATION MANUAL

Potable Water Systems cont.

Alternate Hot Water Installation with
Direct Coupling to a Double Wall Unit
LOOP FIELD
HOT COLD
Dielectric
Unions

FLOW CENTER

Dielectric
Unions P/T
P/T
Ports
Ports

Ball Valve Ball Valve

WaterFurnace WaterFurnace
GEOTANK NSKW06 (Heating Only)
with Double Wall Load Coax

NOTES:
1) Unions and valves must be installed so that acid flushing
of the heat exchanger is possible.
2) Make sure there is not a check valve in the diptube of the
tank.
3) Route thermistor wires to NSKW. Remove yellow
thermistor wires on TB 3 and 4 from control box and
connect thermistor wires from geothermal storage tank.
Set the pump sampling (PS) in the set up of the control
board to continuously (C) sampling (reference Note 5 in
the Wiring Schematic).

12
 NSKW INSTALLATION MANUAL

Hydronic Section
General guidelines are shown below for component Pressure Reducing Valves or Feed Water Valves
selection and design/installation criteria for the piping This valve lowers the pressure from the make-up water line
system. Local codes supersede any recommendations in to the system. Most are adjustable and directional. A “fast
this manual. fill” valve is required for initial filling of the system. Some
have screens, which must be cleaned after the initial filling.
Shut Off/Flow Regulation Valves If there is a restriction in the screen, the system could go to
Use full port ball valves or gate valves for component 0 kPa, potentially causing pumps(s) failure. A valve should
isolation. If valves are going to be used frequently, ball be installed on each side of the pressure reducing valve for
valves are recommended. Globe valves are designed for servicing. Both valves should have tags reading “Do not
flow regulation. Always install globe valves in the correct shut this valve under normal operation – service valve only.”
direction (fluid should enter through the lower body
chamber). Expansion Tanks
Expansion tanks are required on hydronic systems to help
Check valves absorb the pressure swings as the temperature in the
Swing check valves must be installed in the horizontal system fluctuates.
position with the bonnet of the valve upright. Spring check
valves can be mounted in any position. A flow check valve Elbows/Tees
is required to prevent thermo-siphoning (or gravity flow) Long radius elbows or two 45° elbows will lower pressure
when the circulator pump is off or when there are two drop. Standard tees have a greater restriction on the “T”
circulators on the same system. portion than tees designed with angled outlet ports.

Storage (Buffer) Tank Antifreeze

A buffer tank is required for all hydronic heating systems Antifreeze is required if any of the piping system is located
using Envision NSKW heat pumps. The tank should be sized in areas subject to freezing.
to provide 2 gallons [7.6 L] of storage capacity for every
300W of nominal heat pump capacity.
Dielectric Unions
Dielectric unions are recommended whenever connecting
Pressure Relief Valve
two dissimilar metals to one and other to prevent electro-
Most codes require the use of a pressure relief valve if a galvanic corrosion.
closed loop heat source can be isolated by valves. Even
if local code does not require this device, WaterFurnace When using the various types of hydronic heat distribution
recommends its installation. If the pressure relief valve in systems, the temperature limits of the geothermal system
the buffer tank is not already rated at 207 kPa maximum must be a major consideration. In new construction, the
pressure, one must be installed. The pressure relief valve distribution system can easily be designed with the
should be tested at start up for operation. Note that the temperature limits in mind. In retrofits, care must be
waste pipe must be at least the same diameter as the valve taken to address the operating temperature limits of the
outlet (never reduce), and valves may not be added to this existing distribution system. The maximum storage tank
pipe. The bottom of the pipe must terminate at least 15 cm temperature for the Envision NSKW is 54.4°C. Typical in
above the floor. If the piping is connected to a drain, there floor radiant systems require much lower temperatures,
must be an air gap. typically 37.8°-46.1°C, which is ideal for the Envision NSKW.

Backflow Prevention Check Valves

Most codes require backflow prevention check valves.
Note that a single check valve is not equal to a backflow
prevention check valve. Even if local code does not require
this device, WaterFurnace recommends its installation. This
is particularly important if the system will use antifreeze.

13
NSKW INSTALLATION MANUAL

Hydronic Section cont.

Open the screw 2 turns only in the end of the pump motor WaterFurnace Geothermal Storage Tank Thermostat
(if Grundfos® pumps are used) to allow trapped air to be and Thermistor
discharged and to ensure the motor housing has been
flooded.

Route thermistor wires to NSKW. Remove yellow thermistor

wires on TB 3 and 4 from control box and connect
thermistor wires from geothermal storage tank. Set the
pump sampling (PS) in the set up of the control board to
continuously (C) sampling (reference Note 5 in the Wiring
Schematic).

Adequate rate of flow is very important to system

performance and long term reliability. Follow the guidelines NSKW
for recommended flow and pipe sizing in the NSKW
recommendations table.

Yellow Thermistor Wires Connected to TB (3 and 4) on

NSKW Control Board

207 kPa Pressure

RELIEF VALVE Gauge
Air
Vent
LOAD PUMP

HYDRONIC Vent Valve or

Air LOAD P/T Port**
Separator
Back Flow Preventer / Expansion
Pressure Relief Valve Tank

Dielectric HOT COLD

Unions (Piped in
series to
an electric
water heater)
GEO PUMP
STORAGE
TANK DOMESTIC
Dip Tube
FROM TO
HWG HWG

Source OUT

Dielectric
Unions P/T P/T
Ports Ports

Ball Valve
Ball Valve
Source IN
NOTES: WaterFurnace
* A 207 kPa pressure relief valve (Part No: SRV30) should be used in
hydronic applications. NSKW Series
** Vent valve or Pressure/Temperature port at highest point in return line prior to ball valve.

14
 NSKW INSTALLATION MANUAL

Accessories and Options

Geo Storage Tank Dimensions

30° 30°

From Geo To Geo 150 cm Dip Tube

PRIMARY ANODE
99 cm - 80 Gallon
106.7 cm - 119 Gallon 20.3 cm

HOT OUTLET COLD INLET

w/35.6 cm SECONDARY ANODE 132.0 cm DIP TUBE

Approx. 2.54 cm

T&P Yellow Wire attached

VALVE to Thermistor or Thermostat
for Top Exit

HEIGHT Element Location

Lower Sensor Thermistor (12P541-01)

to be used by Water to Water Units
90.8 cm
Optional “From Geo” Connection

13.3 cm

DRAIN VALVE DIAMETER

Lower Thermostat

Element Number Dimensions in cm

Model Gallon [Liter] R Approx Shipping
Wattage of
Number Capacity Value Height Diameter Weight kg
(240 Volt) Elements

GEO-STORAGE-80 80 [303] 4500 1 16 160.6 61.0 92.5

GEO-STORAGE-120 119 [450] 4500 1 16 160.6 71.1 141.1

15
NSKW INSTALLATION MANUAL

Electrical Data
Compressor Load Source Total Min Max
Rated Voltage
Model Pump Pump Unit Circ Fuse/
Voltage Min/Max MCC RLA LRA LRA* FLA FLA FLA Amp HACR
220-240/50/1 198/264 17.5 11.2 60.0 24.0 1.5 4.5 17.2 20.0 30
06
380-420/50/3 342/462 6.5 4.2 28.0 16.8 - - 4.2 5.3 6
220-240/50/1 198/264 27.0 17.3 97.0 34.0 1.5 4.5 23.3 27.6 40
08
380-420/50/3 342/462 10.0 6.4 45.0 27.0 - - 6.4 8.0 10
220-240/50/1 198/264 31.5 20.2 126.0 44.0 1.5 4.5 26.2 31.2 50
12
380-420/50/3 342/462 12.1 7.8 51.5 31.0 - - 7.8 9.8 15
220-240/50/1 198/264 45.0 29.0 130.0 46.0 1.5 4.5 35.0 42.3 70
17
380-420/50/3 342/462 19.0 12.2 87.0 52.0 - - 12.2 15.3 25
1/15/15
Notes:
* - With optional IntelliStart, Type D MCB recommended

NSKW Control Box

Terminal Board
Optional IntelliStart®
(Single Phase Only)
Terminal Power Strip

Power Block
(IntelliStart Only) Power Block

Compressor Contactor

Run Capacitor
(Single Phase Only)

Ground Lug
Reversing Valve Relay
Transformer (Reversible Units Only)

Load Pump Relay

Source Pump Relay

16
 NSKW INSTALLATION MANUAL

Electrical Data cont.

Electrical
Be sure the available power is the same voltage and phase
as that shown on the unit serial plate. Line and low voltage
wiring must be done in accordance with local codes or the
17th Edition IEE Wiring Regulations, whichever is applicable.
Refer to the Electrical Data table for wire and fuse or circuit
breaker sizing information.

NSKW Control Box Relocation

The control box can be installed on the rear of the unit. To
relocate the control box, follow the procedures below.

1. Remove all power sources to the unit.

2. Remove the unit’s top panel.
3. Cut all plastic wire ties to the following:
a) High pressure switch (black wires)
b) Low pressure switch (blue wires)
c) Freeze sensing (yellow wires)
d) Load temperature sensor (black wires)
e) Compressor wires
4. Remove the four screws from the control box.
5. Relocate the control box to opposite end of the unit.
6. Using the screws removed in step 4 above, reattach the
control box.
7. Secure all wires so they do not come in contact with
refrigerant lines.
8. Replace the top of the unit.
9. Replace both access panels.
10. Reapply power sources.

NOTE: If geothermal storage tank is used, connect yellow

thermistor wires from the bottom access panel of the tank
to spade connectors 3 and 4 on the terminal block.

17
NSKW INSTALLATION MANUAL

Wiring Schematics
Heating Only - 240/50/1
Compressor
S C
External External
G G Blue R

Red Black
Load Source Cap
Pump Pump
Tan
T1 T2 T1 T2

NOTE 2 LFB SFB Unit

T2 T1 Power Supply
208-240/50/1
L1 L2 L1 L2
CC
Brown/Blk Blue/Wht
L2 L1
G
Brown/Wht

LPR
Brown
Blue

Blue Black
240V Com
Green/Yellow
Red
208V
NOTE 1
PS1
B C D
Transformer
Red
24V
Black
Black/
Yellow White
24 V

P1
Black/Gry Green/Yellow 1 TEST
C

PIN
LO

LO

Black/Wht LPR Note 3 Orange P3

R LP LP HP HP CC CG HI

R LP LP HP HP CC CG HI

Not Used
CC Blk/Wht
Violet
Microprocessor Control
HP
Black
Black
White/Blue
LP
White/Blue
Red

TB P2
RT 1
X3 X2 X2 X1 X1 ELT ELT RT RT
RT

Black 1
T 2
X3 X2 X2 X1 X1 ELT ELT RT

Black
ELT 3
Yellow
T 4
SI Yellow
5
Violet
6
Orange Violet
7
Orange Not Used
8
Orange Not Used
9
Gray Not Used
10
Not Used
X3
X3

Gray RV RVG MODE

11
12 Interface Panel
SI

Violet

R C Y1 O X1

Legend
Factory low voltage wiring Switch - High pressure
Factory line voltage wiring L1 Field wire lug Notes:
CC - Compressor contactor
Field low voltage wiring RV - Reversing Valve output 1. Taped and wire tied off
ELT - Entering Load Side Water Temperature Ground Switch - Low pressure 2. 3AG 10 Amp fuse
Field line voltage wiring
HP - High pressure switch 3. For cycle load pump with a geo storage tank. Remove
Optional block
LP - Low pressure switch Relay Contacts - the orange wire from the LPR relay coil and install a
Quick connect terminal LPR - Load Pump Relay N.O., N.C. Relay coil jumper between the LPR relay coil and the comp
Screw terminal - RT - Refrigerant Liquid line Temperature contactor coil as shown in the schematic above.
SI - Slave Input relay
field connection
RC - Reversing Valve Coil Capacitor
2
3
1

Fuse P Polarized connector

LFB - Load Pump Fuse Block
SFB - Source Pump Fuse Block
T Thermistor

97P798-14 01/19/12

18
 NSKW INSTALLATION MANUAL

Wiring Schematics cont.

NSKW Reversible with IntelliStart - 240/50/1
Compressor PB
2
S C
External External
G G Blue R 1
Red Red Run Winding
IntelliStart
Load Source Cap Pink Active
Pump Pump
Black Blue Start
Tan
T1 T2 T1 T2
Black
Black Common
NOTE 2 LFB SFB Unit
T2 T1 Power Supply
208-240/50/1
L1 L2 L1 L2
CC
Brown/Blk Blue/Wht
L2 L1
G
Brown/Wht

LPR
Brown
Blue

Blue Black
240V Com
Green/Yellow
Red
208 V
NOTE 1
PS1
B C D
Red Transformer

24V

Black Black/
Yellow White
24 V

P1
Black/Gry Green/Yellow 1 TEST
C

C
PIN
LO

LO
Black/Wht LPR Note 5 Orange P3
R LP LP HP HP CC CG HI

R LP LP HP HP CC CG HI

Not Used
CC Blk/Wht
Black/Org
Violet
Microprocessor Control
HP
Black
Black
White/Blue
LP
White/Blue
Red
RT
Blue Blue TB
T P2
NOTE 4 1
X3 X2 X2 X1 X1 ELT ELT RT RT
RT

Black
RT
Black Black 1
T 2
X3 X2 X2 X1 X1 ELT ELT RT

Org/Gry Black
ELT 3
Yellow Yellow
RVR T 4
SI Yellow Yellow
5
NOTE 3 Violet
6
Org/Grn Violet
Orange 7 Orange
Orange
8
Violet Orange
9
Gray Not Used
10
RVR Not Used
X3
X3

Gray RV RVG MODE

11
12 Interface Panel

RVR SIR Org/Brn

Org/Wht Org/Blk

RC

R C Y1 O X1

Legend
Factory low voltage wiring Switch - High pressure Notes:
Factory line voltage wiring L1 Field wire lug 1. Taped and wire tied off
CC - Compressor Contactor
Field low voltage wiring RV - Reversing Valve Output 2. 3AG 10 Amp fuse
ELT - Entering Load Side Water Temperature Ground Switch - Low pressure 3. Move jumper wire to 5 and 6 for reversible secondary unit
Field line voltage wiring
Optional block HP - High Pressure Switch 4. Black Thermistor - Source Coax
LP - Low Pressure Switch Relay Contacts - Blue Thermistor - Load Coax
Quick connect terminal LPR - Load Pump Relay Contacts N.O., N.C. Relay coil 5. For cycle load pump with a geo storage tank. Remove the
Screw terminal - RT - Refrigerant Liquid Line Temperature orange wire from the LPR relay coil and install a jumper
SIR - Slave Input Relay
field connection between the LPR relay coil and the comp contactor coil
RC - Reversing Valve Coil Capacitor
2
3
1

Fuse P Polarized connector as shown in the schematic above.

LFB - Load Pump Fuse Block
SFB - Source Pump Fuse Block
RVR - Reversing Valve Relay T Thermistor

97P798-16 01/19/12

19
NSKW INSTALLATION MANUAL

Wiring Schematics cont.

Reversible - 380-420/50/3

Compressor

T3 T1

T2

Red Blue Black

Unit T3 T2 T1
Power Supply
CC
380-420/50/3
L3 L2 L1
G

Blk/Wht (69)
Yellow (68)

Green/Yellow (67)

J8 20
23 5VDC Black (20) 20 Black (40)
D09 19
24VAC
24VAC Com
GROUND

Brown (41) 24 -
LST T AI3
Brown (42) 25 + Black (19) 19
White (43) 26 -
LFD T AI5
Wht/Blu (44) 27 + Black (18) 18 Black (38)
Black (45) 28 - D08 18
SFP T AI4 Black (37)
Blk/Red (46) 29 + 17 Black (17) 17
Gray (47) 30 -
EST T AI6 16 Black (16)
Gray/Wht (48) 31 +
A34
A24
A14

16
Blue (49) 32 - D07 15 Black (15)
LLT T AI2
Blue/Wht (50) 33 +
34 5VDC 15 Black (35)
A33

Orange (51) 35 - 14
A12 A21

A25 A22

A35 A31

ELT T AI1 Black (14) 14

Org/Wht (52) 36 +
LED D06 13
A32

37
38 5VDC 12 Black (13) 13 Black (33)
A23
A13
A11

J2 Black (12) 12 Yellow (34)

39 PWM2
40 PWM2 Com D05 11 Black (11) 11 Black (31)
41 PWM1
D04 10 Black (10)
10 Black (30)
J10 9 Black (9)
A15

42 24VAC Com Johnson

NOTE 5 Black (53) 43 DI12 8 Black (8) 9
Black (26) 44 DI11 FX-10 D03 7 Black (7)
Black (22)
Black (55) 45 DI10 8 Black (28)
Black (56) 46 DI9
NOTE 6 Black (57) 47 DI8 Black (6) 7 Black (27)
6
Black (58) 48 DI7
D02 5 Black (5)
6
1 NOTE 1 4 Black (4) HP
NOTE 2 J9 5 Black (25)
Black (59) 49 DI 3/4/5/6/ Com
2 50 DI6
Red (60) 51 DI5 4 Violet (24)
3 Blue (66) 3 Black (3)
Gray (61) 52 DI4
PB2 LP Blue (62) DI3
53 D01 2 3 Orange (23)
Black (63) 54 DI2
9VDC 1
Black (64) 55 Black (2) 2
Black (65) 56 DI1
J
7 Black (1) 1

Yellow (21)
Black (26)
Black (53)
Black (55)
Black (56)
Black (57)
Black (58)
Black (63)
Black (64)
Black (65)

Legend
CC - Compressor contactor Notes:
Internal junction Switch - High pressure CP - Compressor Proving
ELT - Entering Load Water Temp 1 - Switch Blue and Red wires for 380V operation
L1 Field wire lug Switch - Low pressure 2 - Disconnect for -9 degree C load side freeze detection
Factory low voltage wiring ES - Emergency Shutdown
Factory line voltage wiring EST - Entering Source Water Temp 3 - Disconnect for -9 degree C source side freeze detection
Ground Open Jumper HP - High pressure switch
Field low voltage wiring 4 - Acc 1 and ACC 2 outputs are cycled with the compressor.
Relay Contacts- LFD - Load Freeze Detection
Field line voltage wiring LFS - Load Flow Proving Switch 5 - R, C, Y1, and O inputs are for use with an aqua stat.
Optional block N.O., N.C. 6 - If no flow proving switch is being used on the load side, the LF terminal on the terminal board must be
Closed Jumper LLT - Leaving Load Water Temp
Field Zone Sensor Wiring Thermistor LP - Low pressure switch jumpered to the R terminal for the unit to operate.
T
LST - Leaving Source Water Temp 7 - If no flow proving switch is being used on the source side, the SF terminal on the terminal board must
Relay coil 1 2 3 RV - Reversing Valve coil be jumpered to the R terminal for the unit to operate.
P Polarized connector SFP - Source Freeze Protection
SFS - Source Flow Proving Switch 8 - A closed contact will enable the emergency shutdown input (ES) and the compressor proving input (CP).
TB - Terminal Board 9 - Primary over-ride input (POI) on a primary unit must be wired to R through anormally open contact. If the
POI input is on a secondary unit connect the Primary Over-ride output (PO) from the primary unit to the
POI terminal on the secondary unit.
10 - Apply 24VAC to the O terminal for cooling.

20
 NSKW INSTALLATION MANUAL

Wiring Schematics cont.

Reversible - 380-420/50/3 cont.
TB
Field Connection Diagram
(For units using Set Point control mode
with or without a secondary unit.)

Red 380V NOTE 6

NOTE 1 NOTE 5
Transformer

Black R 24VAC 24V COM C

Blue LV Load Valve Output Load Flow

LF
Proving Switch
420V NOTE 8
PB1 Blk/Wht Primary Load
X2 Acc 2 POI
Over-ride Input

X1 Acc 1 Rev Valve O

3

Alarm Source Flow SF

L
Proving Switch
2 To Primary Load Over-ride Input Primary Load
PO Comp 1 Y1
1 (POI) of secondary unit. Over-ride Output
Yellow Secondary Unit Emergency
To Y1 input of secondary unit. SE
Enable Shutdown ES
Yellow (21)
Secondary 9 VDC - Use
To R from secondary unit. SN
for CP and ES 9DC NOTE 7
24VAC Input
Black (36) Secondary Unit Compressor
To O input of secondary unit. SHC
Heat/Cool Proving Switch
CP

R 24VAC
Yellow (29) 1 Black (R)
Load Valve
LV TB
Output
Black (40) 2 Black (LV) Field Connection Diagram
X2 Acc 2 (For units using aqua stat control
Black (38) 3 Black (X2) mode.)
NOTE 3
X1 Acc 1 NOTE 8
Black (35) 4 Black (X1) NOTE 6
Alarm NOTE 5
L
Black (33) 5 Black (L)
Primary Load
PO
Black (31) 6 Black (PO) Over-ride Output
R 24VAC 24V COM C
Secondary Unit
SE Load Flow
Black (30) 7 Black (SE) Enable LV Load Valve Output LF
Proving Switch
Secondary Primary Load
SN X2 Acc 2 POI
Black (28) 8 Black (SN) 24VAC Input Over-ride Input

Secondary Unit X1 Acc 1 Rev Valve O NOTE 9

SHC
Black (27) 9 Black (SHC) Heat/Cool
Alarm Source Flow SF
L
Proving Switch
C 24V COM
10 Black (C) Primary Load
PO Comp 1 Y1 Aqua Stat Y1
Over-ride Output
Load Flow
LF Secondary Unit Emergency
NOTE 5 Black (53) 11 Black (LF) Proving Switch SE Shutdown ES
Enable
Primary Load Secondary 9 VDC - Use
Black (55) POI SN 9DC NOTE 7
12 Black (POI) Over-ride Input 24VAC Input for CP and ES

Secondary Unit Compressor

Violet (70) O Rev Valve SHC
Heat/Cool Proving Switch
CP
Black (56) 13 Black (O)
Black (54) Source Flow
SF
Black (57) 14 Black (SF) Proving Switch
CC NOTE 6
Y1 Comp 1
Green/Yellow (72) Black (58) 15 Black (Y1)
Emergency
Orange (39) 16 Black (ES) ES Shutdown

RV 9 VDC - Use
17 Black (9DC) 9DC for CP and ES

Compressor
CP
18 Black (CP) Proving Switch

97P799-12 1/19/12

21
NSKW INSTALLATION MANUAL

Heat Pump Control

NSKWs come with a factory installed control board that is IntelliStart®
capable of receiving commands from the internal controller The optional IntelliStart single phase soft starter will reduce
provided with the heat pump. An alternative method is the normal start current (LRA) by 60%. Using IntelliStart
to control the heat pump using an external field supplied also provides a substantial reduction in light flicker, reduces
Aquastat or thermostat that will turn the compressor on/off startup noise, and improves the compressor’s start behavior.
based on leaving water temperature.

When the heat pump is controlled by the internal controller

it is called “Primary Mode” which allows the user to adjust
the comfort level by adjusting temperature setting on the
heat pump display. For more information refer to panel
configuration on standard controls.

An additional way of controlling the heat pump is by use of

an external control such as an aquastat that gives a signal
to the heat pump controlling to enable the compressor
output. This mode of control is referred to as “Secondary
Mode” and requires components from an external field
supplied source. For more information on this control
strategy refer to external control section of the manual.

22
 NSKW INSTALLATION MANUAL

External Control
Primary Mode Secondary Mode
In dedicated heating or cooling units, the unit is controlled In dedicated heating or cooling units, secondary mode
by the internal controller. Compressor output is determined allows the unit to be controlled by an external source.
by the entering load-side water temperature. Compressor output is determined by the Y1 input only.

The secondary output will be energized if two conditions The secondary output will be energized after the following
occur: condition occurs:
1. The initial temperature is greater than IC away from the
set point. 1. The change in temperature in a given period of time P is
2. The change in temperature in a given period of time P is less than d.
less than d.
In reversible units, secondary mode allows the unit to
In a reversible unit, the unit is controlled by the internal be controlled by an external source. Compressor output
controller. Compressor output is determined by the is determined by the Y1 input and the reversing valve
entering load-side water temperature. For reversible units, is determined by the O input. In reversible units, the
the jumper wire must be positioned across terminals 6 and jumper wire must be positioned across terminals 5 and 6.
7, (factory default set to this position). Reversible units do Reversible units do not have a secondary input.
not have a secondary output.
NOTES: SL in the configuration menu must be set to 1. P
NOTES: SL in the configuration menu must be set to 0, and d must be setup for each secondary unit.
(factory default). All parameters should be checked for
each application on primary unit, (refer to the parameter Wiring an Aquastat - Reversible Unit
table).
• To create a secondary unit, set SL to 1 in the
configuration menu.
WARNING: Reversible units cannot be
• Position the jumper wire in the control box across
staged.
terminals 5 and 6.

Aquastat Wiring for Dedicated Heating or Cooling Unit Aquastat Wiring for Reversible Unit

Secondary Unit Typical Aquastat

(SL=1)

Typical Aquastat

Secondary Unit
C O
(SL=1)
G Y1
W1 W2
L S
C O
X1 X2
Y1 = Compressor call 1
G Y1
R = 24VAC Y2 R 2
Jumper 3
W1 W2
Wire
4 L S
5
X1 X2
6
7 Y2 R
8
9 Y1 = Compressor call
10 O = Reversing valve call
11
R = 24VAC
12

Control Box

Note: Jumper wire must be

moved to terminals 5 & 6.
Control Box

23
NSKW INSTALLATION MANUAL

External Control cont.

Staging with Primary/Secondary Mode Wiring for Primary/Secondary Unit Staging
Staging is only possible with dedicated heating or cooling
units. Reversible units cannot be staged. Staging can be C O C O C O
G Y1 G Y1 G Y1
accomplished with primary/secondary modes or by using W1 W2 W1 W2 W1 W2

an aquastat. L
X1
S
X2
L
X1
S
X2
L S
X1 X2
Y2 R Y2 R Y2 R

WARNING: Do not stage more than 6 units.

The first stage must be setup as a primary unit. All other

units must be setup as secondary units. The set point is
stored in the primary unit. Once the set point in the primary
unit has been satisfied, all units will immediately shutdown.
First Stage Second Stage Third Stage

NOTES: X1 = Secondary output

Y1 = Compressor call

Staging with Aquastat Wiring for Dedicated Heating or Cooling Units with
Aquastat
When staging units using an Aquastat, all units must be ( )

setup as secondary units. Typical Aquastat

C O C O
WARNING: Do not stage more than 6 units. G Y1 G Y1
W1 W2 W1 W2
L S L S
X1 X2 X1 X2
Y2 R Y2 R

First Stage Second Stage

NOTES: X1 = Secondary output

Y1 = Compressor call
R = 24 VAC

24
 NSKW INSTALLATION MANUAL

Converting to a Dedicated Cooling Unit

Procedure to Convert a Heating Only Unit to a 13. Open the control box.
Cooling Only Unit 14. Find the connection marked “P4” as shown in the
All non-reversible NSKW units are built at the factory as Control Board with Jumper illustration.
dedicated heating units. Follow the procedures below to 15. Move the “P4” jumper from across 1 and 2 to across 2
make the unit a dedicated cooling unit. and 3.
1. Shut off all power to the unit. 16. Close the control box and secure the screws.
2. Remove the top and access panel. 17. Replace the top and access panel.
3. Remove the brass in-well thermistor from the load 18. Make sure all screws have been re-installed.
water-in line. 19. Turn on the power.
4. Remove the brass plug from the source water-in line. 20. Using the touch-pad, press the UP arrow.
5. Place new Teflon® tape on the threads of the brass in- 21. The displays should blink “44” to show set point. Now,
well thermistor. the unit should operate as a cooling only unit.
6. Thread the brass in-well thermistor into the source
water-in line. Jumper Pin Location
7. Make sure the thermistor wires do not touch the The location of the jumper pin determines the controller’s
discharge line. mode of operation. Move the jumper pins to the correct
8. Place new Teflon® tape on the threads of the brass plug. location for dedicated heating, dedicated cooling or
9. Thread the brass plug into the load water-in line. reversible settings as indicated below.
10. Refer to the labels on the unit for the location of ports
and lines. Dedicated heating -1&2*
11. Connect the “Source Water-In” line to the port marked Dedicated cooling -2&3
“Load Water-In.” Then, connect the “Source Water-Out” Reversible -3&4*
line to the port marked “Load Water-Out.”
12. Connect the “Load Water-In” line to the port marked * Indicates factory setting.
“Source Water-In.” Then, connect the “Load Water-Out”
line to the port marked “Source Water-Out.” NOTE: A reversible unit can not be configured to heating only.

Control Board with Jumper P5 Key Pad

(Interface)

P4
P9
Not Used

P2

P1

25
NSKW INSTALLATION MANUAL

Unit Startup
Before Powering Unit 8. Press the down arrow on the keypad to reduce the
Check the following: set point below the incoming load temperature.
• High voltage wiring is correct and matches the Compressor should shut off and the load pump should
nameplate. shut off 30 seconds after the compressor.
• Fuses, breakers and wire size are correct. 9. Wait 7 minutes. The load pump should start to sample
• Piping is completed and water system has been cleaned load temperature.
and flushed. 10. Compressor and source side circulator should not start.
• Air is purged from the closed loop system. 11. Press the up arrow on the keypad to increase the
• Isolation valves are open and loop water control valves or set point to 5 degrees above the water temperature
loop pumps are wired. displayed on the LED screen.
• Service/access panels are in place. 12. Three minutes after the load pump activates, the
compressor and source pump should activate.

Primary Unit Startup

1. Apply power to the unit. Upon power up, the unit will
Secondary Unit Startup
display the current operation mode.
• H for dedicated heating. 1. Apply power to the unit.
• C for dedicated cooling. 2. After a three to five-minute delay, the water temperature
• U for reversible units. shall be sampled. If the controller receives a remote
2. Press the mode button. The LED screen will display the aquastat signal, the compressor shall activate.
current entering water temperature. The load pump will 3. Verify that the compressor and load side, source side
activate after a 5 minute delay. pumps are running.
3. Once the load pump has been active for 3 minutes, the 4. By using a pressure gauge and the PT ports, check the
controller will sample the temperature of the water pressure drop through both the load and source coaxes,
system. In heating mode, when the temperature of the and compare this to the Pressure Drop tables.
water shown on the display is lower than the set point 5. After determining the flow rates, use a thermometer and
the compressor will activate. the PT ports to determine the change in temperature on
4. By using a pressure gauge and the P/T ports, check the both the load and source side coaxes.
pressure drop through both the load and source coaxes. 6. Compute the formula l/s flow rate X change in
Compare this to the capacity tables in the specification temperature x 4.2 (4.1 on source side if antifreeze/brine
catalog to verify the proper flow rate through the unit. is used in the loop) = Heat of Extraction on the source
5. Verify that the compressor, load side and source side side in heating, Heat of Rejection on the source side in
pumps are operating. cooling. To ensure proper operation, compare these
6. After determining the flow rates, use a thermometer and values to the HE/HR tables.
the PT ports to determine the change in temperature on 7. Press the down arrow on the control to disrupt the
both the load and source side coaxes. remote aquastat signal. Unit should shut off.
7. Compute the formula l/s flow rate X change in 8. Instruct the owner or operator about the correct control
temperature x 4.2 (4.1 on source side if antifreeze/brine and system operation.
is used in the loop) = Heat of Extraction on the source
side in heating, Heat of Rejection on the source side in
cooling. To ensure proper operation, compare these
values to the HE/HR tables.

26
 NSKW INSTALLATION MANUAL

Standard Board - Control Features

Anti Short Cycle Time selected, the control will respond immediately to a
The anti short cycle time consists of a three minute recognized call or termination of call for heat or cool
minimum “off” time plus a randomly chosen 0-2 minute subject to minimum run times and anti short cycle delays.
additional “off” delay. The random delay is chosen by the
control after each compressor shut down. The 3-5 minute Test Mode
startup delay is applied after all compressor shutdowns and Connection of a jumper wire from chassis ground to P3
also to system startups due to ac power interruption. will place the control in the test mode. This shortens most
timing delays for faster troubleshooting. In the Primary
Safety Controls Mode the control will respond immediately if a demand
The control board receives separate signals for a high is present. The anti-short cycle delay is replaced by a
pressure switch for safety, low pressure switch to prevent 10 second pump and compressor on delay. Minimum
loss of charge damage, and a low suction temperature for compressor run time becomes 15 seconds. Test mode will
freeze detection. Upon a 30-second measurement of the remain in effect for a maximum of 15 minutes at any one
fault (immediate for high pressure), compressor operation is time should the jumper remain in place.
suspended and the fault will be shown on the display.
Fault Conditions
Setpoint Temperature Ranges There are two classes of faults, retry faults and no retry
In Primary mode, the heating temperature setpoint range faults. Retry faults allow the system to try 2 additional times
is adjustable from 15.5°C to 54.4°C with an adjustable to establish operation before displaying the fault condition
deadband range of 1° - 15°F. The cooling setpoint and entering lockout. No-Retry Faults prevent compressor
temperature is adjustable from -17.7°C to 29.4°C with a fixed operation for the duration of the fault. If the fault activity
non-adjustable deadband of 5°F. ceases while the system is inactive, the fault code is cleared
from the display and operation is permitted.
NOTE: Deadband adjustments are in degrees Fahrenheit
(°F) only. Retry Faults
High pressure, low pressure and freeze detection
faults are retried twice before locking the unit out and
Load Pump Control displaying the fault condition.
There are two options for controlling the load pump, Pump
Sampling (PS) or Continuous Pump (C), and these are High Pressure (HP)
selectable in the service Menu. Compressor operation will be disabled immediately
when the normally closed high-pressure switch is
Pump Sampling (PS) opened momentarily (set at 4.1 kPa). The LED display
In Primary Mode, the control operates on a 10 minute shall read “HP” only when the control has completed
sample cycle in which the load pump is turned on and two retries, and is in lockout. The pump continues to
run to obtain a meaningful sample of the temperature operate throughout the retry period.
the load is presenting. If the water temperature
measured after the pump has been on for PS minutes Low Pressure (LP)
(selected and adjusted from the Service Menu) is Compressor operation will be disabled when the
outside the user selectable deadband amount, dB normally closed low-pressure switch (set at 275 Pa)
(also selected and adjusted from the Service Menu), has opened for 30 continuous seconds (if the bypass
the compressor is turned on and Heating or Cooling period has been satisfied). The Low Pressure switch is
is initiated. If the water temperature is within the bypassed (ignored) for two minutes after startup. The
deadband of the set point when sampled, the pump LED display shall read “LP” only when the control has
shuts off and is idle for (10 – PS) minutes when it starts completed two retries, and is in lockout. The pump
another PS minute sample period. For example, if continues to operate throughout the retry period.
the PS setting is two minutes, the pump will run for 2
minutes before sampling the load temperature. If the Freeze Detection (FP)
water temperature is within the selected dead band Compressor and loop pumps will be disabled if the
temperature of the set point, the pump will shut off control senses that the refrigerant loop temperature
for 10 – 2 = 8 minutes before beginning another pump drops below the FP value (set in the service menu) for
sampling cycle. Heating deadband is selectable in the 30 continuous seconds (if the bypass period has been
Service Menu while the Cooling deadband is non- satisfied). If the compressor and the loop pump outputs
adjustable and fixed at 5°F. are disabled because of this condition, the LED display
shall read “FP.” There is a two (2) minute by-pass timer
Continuous Pump Mode (C) for the freeze detection at compressor start up.
If continuous pump mode (PS=C In Service Menu) is

27
NSKW INSTALLATION MANUAL

Standard Board - Control Features cont.

No-Retry Faults Freeze Detection Probe Closed (dC)
High Temperature, Water Temperature Probe Open, Compressor and pump operation will be disabled when
Water Temperature Probe Closed and Brown Out faults the control senses that the freeze detection probe is
prevent compressor operation for the duration of the closed or has no resistance. The LED display shall read
fault. If the fault activity ceases while the system is “dC.”
inactive, the fault code is cleared from the display and
operation is permitted. Brown-Out (B0)
All operation will be disabled when the control voltage
High Temperature falls below 18VAC for 10-15 continuous seconds.
Compressor operation will be disabled when the control
senses an entering load side water temperature of Resetting Lockouts
54.4°C regardless of mode.
To reset any lockout condition, place the unit into the
standby mode for at least 5 seconds. After the lockout
Water Temperature Probe Open (PO)
has been reset, the fault display will be turned off. Cycling
Compressor and pump operation will be disabled when
control power will also clear the display. Non-Retry Faults
the control senses that the water probe is open or has
must be cleared for the display and lockout to clear.
infinite resistance. The LED display shall read “PO.”

Water Temperature Probe Closed (HC) Power Down (power outage)

Compressor and pump operation will be disabled when The controller will store its Service Menu settings and
the control senses that the water probe is closed or has current Mode selection in non-volatile memory so that these
no resistance. The LED display shall read “HC.” settings are retained through any power outage. Current
operating conditions are not stored and the controller must
Freeze Detection Probe Open (dO) evaluate its current conditions.
Compressor and pump operation will be disabled when
the control senses that the freeze detection probe is
open or has infinite resistance. The LED display shall
read “dO.”

28
 NSKW INSTALLATION MANUAL

Standard Control - Panel Configuration

The control panel allows you to access the service menu Control Panel
on the unit. The control panel has three 7-segment LED
screens that display the:
• Water temperature
• Configuration menu

There are six (6) LED indicators that indicate when the
SECONDARY OUTPUT is active or the unit is on one of the
following modes:
• Standby Mode
• Heating Mode
• Cooling Mode
• Primary (Master) Mode

The control panel has both UP and DOWN (arrow) buttons

and a MODE button. The UP and DOWN buttons allow you
to change the set point or scroll through the configuration
menu. The MODE button allow you to change mode as well
as enter and exit parameters while in configuration mode.

Control Panel Configuration

The configuration menu allows you to properly set and Changing the Setpoint
adjust all of the unit’s operating parameters to fit your
1. Pressing the UP or DOWN arrow once will display the
application.
setpoint.
2. The setpoint will flash.
To enter configuration mode and configure parameters,
3. When the setpoint is flashing, the UP and DOWN arrow
follow these procedures:
will change the setpoint by one degree.
1. Hold down both the UP and DOWN buttons
4. In Primary mode, the heating temperature setpoint range
simultaneously for five seconds, or until the LED screen
is adjustable from 15.5°C to 54.4°C with an adjustable
displays “LC”.
deadband range of 1° - 15°F. The cooling setpoint
2. Press the UP or DOWN arrow until “50” is displayed.
temperature is adjustable from -17.7°C to 29.4°C with a
3. Press the MODE button. The screen should display “SC” fixed non-adjustable deadband of 5°F.
to indicate the controller is in configuration mode.
4. Once in configuration mode, press the UP or DOWN NOTE: Deadband adjustments are in degrees Fahrenheit
arrow to scroll through the menu. (°F) only.
5. Press the MODE button to enter the parameter. (Refer
to the parameter table below for a list of configurable
parameters.)
6. Once in the parameter, press the UP or DOWN arrow to
change the parameter.
7. Press the MODE button to return to the main menu.

NOTE: The controller will exit the configuration mode after

30 seconds if no key is pressed.

29
NSKW INSTALLATION MANUAL

Standard Control - Panel Configuration cont.

Remote Aquastat Secondary Mode (Y1)
In secondary mode the compressor output is determined by an external aquastat. The compressor shall engage 10 seconds
after the Y1 call has been received. The compressor shall de-activate 10 seconds after the Y1 has been removed. The
secondary output is controlled by a Derivative Controller. If the change in the water temperature is less than a selected
value (d) in a selected period of time (P), the secondary output shall activate.

Parameter Functions and Settings

Factory
Parameter Function Description Range Increments
Setting
Calibrate This will allow the temperature displayed to be
SC the Water adjusted to match a temperature reading from an 0° -9° to 10° 1
Sensor external source.
Dead Band This parameter is used to determine when
(Heating) the compressor should be activated. If the
temperature is below the setpoint minus the dB
dB 1°F 1° to 15° 1
value (in heating mode) then the compressor will
activate. The cooling deadband is fixed at 5°F
and non-adjustable.
Celsius/ This parameter selects the units for which the
CF Fahrenheit temperature will be displayed. F F or C N/A
Selection
Freeze There are three settings for this parameter; OL,
Detection CL, and P. OL is the open loop setting which
FP corresponds to 32°F (0°C). CL is the closed loop 32°F P,CL,OL N/A
setting which is 15°F (-10°C). P is the process
setting which is 5°F (-15°C).
Primary/ Primary mode utilizes an internal aquastat to
Secondary determine the activity of the compressor. In 0 1 = Secondary
SL 0 or 1
Setting secondary mode the compressor output is (Primary) 0 = Primary
determined by an external aquastat.
Initial This parameter is used to determine the state of
Condition the secondary output of the primary unit. If the
IC actual water temperature is greater than the IC 10° 0° to 20° 1°
value away from the set point, the secondary
output will be activated.
Derivative This parameter is used to determine the state
of the secondary output of the primary and
d secondary unit. If the change in temperature is 1°F 0° to 5° 1°
less than the d value the secondary output will
activate.
Period This determines how often the derivative will be
P 5 min 1 to 5 min 1 min
calculated.
Pump This parameter determines how long the pump
Sampling is activated before the controller takes a sample
Time of the water temperature. The range of this 1 to 5 min
PS 3 min 1 min
Selection parameter is from 1 to 5 minutes and is factory or C
set to 3 minutes. The pump can also be set to run
continuously when PS is set to C.
Freeze This displays the current temperature of the
Fd Detection freeze detection sensor. N/A 0° to 130° N/A
Display

NOTE: In Celsius mode, only the temperature display will show degrees Celsius. Deadband, Derivative, Freeze Detection
display, and other functions will still use degrees Fahrenheit (°F).

30
 NSKW INSTALLATION MANUAL

Optional Controls
FX10 Control The most unique feature is integrating the FX10 into the
The FX10 control provides unparalleled capability Envision Series as both the heat pump and DDC controller
in several areas including performance monitoring, providing both a cost advantage and providing features
energy management, and service diagnosis, and then not typically found on WLHP controls. This integration
communicates it all thru standard DDC protocols like N2, allows heat pump monitoring sensors, status and service
Lon and BACnet (MS/TP @ 19,200 Baud Rate). diagnosis faults to be communicated thru the DDC direct
to the building automation system (BAS), giving building
supervisors detailed and accurate information on every
piece of equipment without removing an access panel!

Control General Description Application Display/Interface Protocol

FX10 The FX10 microprocessor control is self Cannot be integrated with Optional Medium Standalone
contained control featuring LP, LOC, HP, LWT, centralized building automation User Interface (MUI)
and condensate overflow fault modes can be systems. Software can be can be used as a
displayed on BAS system. Optional handheld customized for specific field service tool.
Medium User Interface (MUI) Control can be projects.
used for additional setup or servicing.
Program customization is possible.

FX10 w/N2 FX10 Control functions as both unitary heat Same as FX10 with Johnson Optional Medium Johnson
pump control and DDC communication, Controls N2 BAS compatibility. User Interface (MUI) Controls
therefore detail operational and fault can be used as a N2 network
information is available to BAS. Other field service tool.
features are same as FX10 with addition of
Johnson Controls N2 compatibility.

FX10 w/LonWorks FX10 Control functions as both unitary heat Same as FX10 with LonWorks Optional Medium LonWorks
pump control and DDC communication, BAS compatibility. User Interface (MUI)
therefore detail operational and fault can be used as a
information is available to BAS. Other field service tool.
features are same as FX10 with addition of
LonWorks compatibility.

FX10 w/BACnet FX10 Control functions as both unitary heat Same as FX10 with BACnet Optional Medium BACnet - MS/TP
pump control and DDC communication, (19,200 Baud Rate)
BAS compatibility. User Interface (MUI)
therefore detail operational and fault can be mounted or
information is available to BAS. Other Due to communication speed, used as field service
features are same as FX10 with addition of no more than 30 units should tool.
BACnet compatibility. be connected to a single trunk
of the network.

31
NSKW INSTALLATION MANUAL

Optional Controls - FX10 cont.

FX10 Advanced Control Overview
• The Johnson Controls FX10 board is specifically designed
for commercial heat pumps and provides control of the
entire unit as well as input ports for Open N2, LonTalk,
BACnet (MS/TP @ 19,200 Baud Rate) communication
protocols as well as an input port for a user interface.
The user interface can be used to aid in diagnostics and
unit setup and is optional on all NSKW units. A 16-pin low
voltage terminal board provides terminals for common
field connections. The FX10 Control provides:
• Operational sequencing
• High and low-pressure switch monitoring Main FX 10 Board
• General lockout
• Freeze Detection Temperature Sensing Optional Plug-in Communication Modules -
• Lockout mode control (compatible with standard BAS protocols)
• Emergency shutdown mode
• Open N2
• Random start and short cycle protection
• LonTalk
• BACnet (MS/TP @ 19,200 Baud Rate, 30 unit max per
Short Cycle Protection trunk line)
Allows a minimum compressor “off” time of five minutes
and a minimum “on” time of two minutes. Display
One local display is optional on all NSKW units. Up to
Random Start 2 displays, either 1 local and 1 remote, or 2 remote. (A
A delay of 1 to 120 seconds is generated after each power- 2-display configuration requires identical displays.) Local
up to prevent simultaneous startup of all units within a display can be up to 3 meters from the controller, power
building after the release from an unoccupied cycle or supply, and data communication. Remote display can be up
power loss. to 300 meters from the controller. Remote display must be
independently powered with data communication done via
Emergency Shutdown 3 pole shielded cable.
A field-applied dry contact can be used to place the control
into emergency shutdown mode. During this mode, all Control Timing & Fault Recognition Delays
outputs on the board are disabled. Lead compressor “ON” delay ..........................................90 seconds
(not applicable for single compressor models)
Freeze Detection Temperature Limit Minimum compressor “ON” time ...................................... 2 minutes
(except for fault condition)
Field selectable for -9.4° or -1.1°C
Short cycle delay ..................................................................... 5 minutes
Random start delay .......................................................0-120 seconds
Installation Options High pressure fault ................................................................. <1 second
• Standalone controlled by standard aqua stat Low pressure fault ...............................................................30 seconds
• Integrated into BAS by adding communication module Freeze detection fault ................................................... 0-30 seconds
Low pressure/freeze fault bypass..................................... 2 minutes
Accessory Outputs
Quantity 2. Cycled with the compressor. Field selectable for
normally open (factory default) or normally closed through
the building automation system or user interface.

User Interface
4 x 20 backlit LCD

32
 NSKW INSTALLATION MANUAL

Optional Controls - FX10 cont.

FX10 Microprocessor and BAS System DDC Operation and Connection
Other optional network protocol boards that can be added
to the FX10 are:
• Johnson Control N2
• LonWorks
• BACnet
- MS/TP @ 19,200 Baud rate
- Limit devices to 30 on a single trunk line.

Control and Safety Feature Details

Emergency Shutdown
The emergency shutdown mode can be activated by a
command from a facility management system or a closed
contact on BI-2. The default state for the emergency
The FX10 is a microprocessor based control that not shutdown data point is off. When the emergency
only monitors and controls the heat pump but also can shutdown mode is activated, all outputs will be turned
communicate any of this information back to the building off immediately and will remain off until the emergency
automation system (BAS). This means that not only does shutdown mode is de-activated. The first time the
the control monitor the heat pump at the unit you can also compressor starts after the emergency shutdown mode
monitor and control many of the features over the BAS. has been de-activated, there will be a random start delay
This clearly puts the FX10 in a class of its own. present.

The control will enumerate all fault conditions (HP, LP,

Lockout Mode
LOC, and Freeze Detection) over a BAS as well as display
them on a medium user interface (MUI). HP, LP, and Freeze Lockout mode can be activated by any of the following
Detection faults can all be reset over a BAS. A Loss Of fault signals: refrigerant system high pressure, refrigerant
Charge fault can not be reset or bypassed until the problem system low pressure, or freeze detection. When any valid
has been corrected. A MUI is invaluable as a service tool for fault signal remains continuously active for the length
the building service team. of its recognition delay, the controller will go into fault
retry mode, which will turn off the compressor. After the
The unit can be commanded to run by applying Y1, Y2, and compressor short cycle delay, the compressor will attempt
O commands to the terminal board or commanded through to operate once again. If three consecutive faults occur
a BAS. The control board is wired with quick connect in 60 minutes, the unit will go into lockout mode, turning
harnesses for easy field change out of a faulty control off the compressor, enabling the alarm output until the
board. An alarm history can be viewed through the MUI and controller is reset. If the control faults due to the low
will be held in memory until the unit is power cycled. pressure input being open during the pre-compressor
startup check, the control will go into lockout mode
The FX10 control has unused analog and digital inputs for immediately, disabling the compressor from starting and
field installed items such as water temperature or current enabling the alarm output. The lockout condition can be
status switches. The control has unused binary and PWM reset by powering down the controller, by a command from
outputs that can be commanded over the BAS for field use. the BAS, or by holding the ESC and Return keys on the user
A Medium User Interface (MUI) for control setup and interface for 5 seconds.
advanced diagnostics is standard on all NSKW units.

Standard Features
• Anti Short Cycle
• High Pressure Protection
• Low Pressure Protection
• Freeze Detection
• Loss of Charge Detection
• Random Start
• Display for diagnostics
• Reset Lockout at disconnect or through BAS
• 2 Accessory outputs
• Optional BAS add-on controls

33
NSKW INSTALLATION MANUAL

Optional Controls - FX10 cont.

Freeze Detection Sequence of Operation
The freeze detection sensor will monitor the liquid Power Fail Restart
refrigerant temperature entering the water coil in the When the controller is first powered up, the outputs will
heating mode. If the temperature drops below the freeze be disabled for a random start delay. The delay is provided
detection trip point for the recognition delay period, the to prevent simultaneous starting of multiple heat pumps.
condition will be recognized as a fault. The freeze detection Once the timer expires, the controller will operate normally.
trip point will be factory set for -1.1°C and will be field
selectable for -9.4°C by removing a jumper wire on BI-4
for the source and BI-5 for the load. The freeze detection
Random Start Delay
fault condition will be bypassed for 2 minutes at normal This delay will be used after every power failure, as well as
compressor startup to allow the refrigeration circuit to the first time the compressor is started after the control
stabilize. If the freeze detection sensor becomes unreliable exits the unoccupied mode or the emergency shutdown
at any time compressor operation will immediately be mode. The delay should not be less than 1 second and not
suspended until the problem is corrected. This will be longer than 120 seconds. If the control is in test mode the
displayed as an alarm on the BAS and the MUI. This alarm random start delay will be shortened to 5 seconds.
will be reported as “Water Low Temp Limit”.
Compressor Minimum On Delay
High Pressure The compressor minimum on delay will ensure that the
The high-pressure switch shall be a normally closed (NC) compressor output is enabled for a minimum of two (2)
switch that monitors the systems refrigerant pressure. If minutes each time the compressor output is enabled. This
the input senses the high-pressure switch is open it must will apply in every instance except in the event the high
disable the compressor output immediately and count the pressure switch is tripped or emergency shutdown then the
fault. The compressor minimum on time does not apply if compressor output will be disabled immediately.
the high-pressure switch opens. The compressor will not
restart until the compressor short cycle time delay has Compressor Minimum Off Delay Time
been satisfied. The compressor minimum time delay will ensure that the
compressor output will not be enabled for a minimum
Low Pressure of five (5) minutes after it is disabled. This allows for
The low-pressure switch shall be a normally closed (NC) the system refrigerant pressures to equalize after the
switch that monitors the systems refrigerant pressure. compressor is disabled.
The input shall be checked 5 seconds before compressor
start up and then ignored for the first 2 minutes after the Heating Cycle
compressor output (BO-2) is enabled. If the switch is open The control will run the unit in heating mode when there is
continuously for 30 seconds during compressor operation no command on the O/B terminal on the terminal board.
the compressor output (BO-2) will be disabled. The
compressor will not restart until the compressor short cycle
Cooling Cycle
time delay has been satisfied.
The control will run the unit in cooling mode when there is
a command on the O/B terminal on the terminal board.
Alarm Outputs
The alarm output will be enabled when the control is in
MUI Alarm History Reporting
the lockout mode and will be disabled when the lockout is
reset. If a fault occurs the fault will be recorded in history for
display on the medium user interface in the History Menu.
Each fault type will be displayed in the history menu with
Test Mode
a number between 0 and 3. A reading of 3+ will mean that
By holding the ESC and down arrow keys on the MUI for 5 fault has occurred more than three times in the past. The
seconds will put the control into test mode. In test mode history menu can be cleared with a power cycle only. Alarm
the random start delay and the compressor fixed on delay date and time are not included in the history.
time will both be shortened to 5 seconds and the reversing
valve will be allowed to cycle without shutting down the
compressor. If an MUI is connected to the control LED 8 will
flash and the words “Test Mode Enabled” will be shown on
the LCD display when the control is in test mode. Test mode
will be disabled after a power cycle, 30 minute timeout, or
by holding the ESC and Up arrow keys on the MUI.

34
 NSKW INSTALLATION MANUAL

Optional Controls - FX10 cont.

Inputs and Outputs Configuration Control Accessories
Field Selectable Options • A99 Sensor
Load and Source Freeze Detection Setpoint • MUI (LCD User interface) for diagnostics and
The freeze detection setpoint input allows you to commissioning
adjust the freeze detection setpoint for either the • MUIK3 - Panel Mount, Portable
load or source sides of the heat pump. When the • MUIK4 - Wall Mount
jumper is installed on BI-5 the load freeze detection
setpoint is factory set for -1.1°C. When the jumper on
BI-5 is removed the load freeze detection setpoint will
be -9.4°C. When the jumper is installed on BI-4 the
source freeze detection setpoint is factory set for -1.1°C.
When the jumper on BI-4 is removed the source freeze
detection setpoint will be -9.4°C. NOTE: Piping circuit
must be antifreeze protected to the set levels or the
warranty will be voided.

Accessory Output
The Accessory Outputs will be energized 90 seconds
prior to the compressor output being energized. When
the compressor output is turned off the accessory
outputs will be deactivated immediately. The outputs
are selectable for normally open or normally closed
operation through the Medium User Interface or through
the Building Automation System.

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NSKW INSTALLATION MANUAL

Reference Calculations Pressure Drop

Heating Calculations: Cooling Calculations: Pressure Drop (kPa)
Model L/s
HE HR 0°C 15°C 25°C 35°C 50°C
LWT = EWT - LWT = EWT +
L/s x 4.2* L/s x 4.2* 0.25 6.2 4.8 4.1 3.4 2.8

NOTE: * When using water. Use 4.1 for 15% methanol/water 0.35 13.8 13.1 12.4 11.7 10.3
06
or Environol solution. 0.45 22.1 20.7 20.0 19.3 17.9
0.55 30.3 29.0 27.6 26.2 25.5
0.30 6.2 4.1 3.9 3.7 3.4
0.45 15.9 14.1 13.4 12.8 12.1
08
0.65 25.5 24.1 23.0 21.9 20.7
0.80 34.5 32.4 30.3 29.0 27.6
0.50 11.7 9.7 9.4 9.2 9.0
0.75 24.8 23.4 22.0 20.5 19.0
12
1.00 38.6 37.2 34.5 31.7 29.0
1.20 57.2 55.8 52.4 49.6 46.9
0.60 22.1 20.7 19.5 18.3 17.2
0.90 37.9 36.5 35.2 33.5 32.1
17
1.20 54.5 52.4 50.3 48.7 46.9
1.50 79.3 77.9 75.8 74.5 72.4

NOTE: Temperatures are Entering Water Temperatures 2/14/12

Operating Limits
Cooling Heating Heating with High Source Temperatures
Operating Limits
°C °C Heating water with a water to water unit using high source
temperatures can lead to operating conditions that fall
Source Side Water Limits
outside of the system operating range. The condition occurs
Minimum Entering Water -1.1 -6.7
when the loop (source) temperature exceeds 21.1°C with
Normal Entering Water 29.4 15.6 a full flow of 0.054 L/s per kW. Under this scenario, the
Maximum Entering Water 43.3 32.2 evaporating temperature can fall outside of the compressor
Load Side Water Limits operating window.
Minimum Entering Water 10.0 15.6
To allow the system to operate correctly, restricting the
Normal Entering Water 15.6 37.8
source side flow when the evaporating temperature exceeds
Maximum Entering Water 32.2 48.9 12.7°C is recommended. One way of accomplishing this is to
NOTES: Minimum/maximum limits are only for startup use a flow-restricting valve on the source loop circuit that
conditions, and are meant for bringing the space up to is controlled by the evaporating temperature. Locate the
occupancy temperature. Units are not designed to operate sensing device on the refrigerant inlet of the evaporator.
at the minimum/maximum conditions on a regular basis.
The operating limits are dependent upon three primary As an alternative to the evaporating temperature, the
factors: 1) entering source temperature, 2) entering load suction line temperature can be monitored with the same
temperature, and 3) flow rate L/s. When any of the factors control capability. In this control, temperature should be a
are at the minimum or maximum levels, the other two maximum of 18.3°C.
factors must be at the normal level for proper and reliable
unit operation. Consult the Performance Tables for each
model to determine allowable normal operating conditions.
Units are not designed for outdoor installation.

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 NSKW INSTALLATION MANUAL

Flow Rates
Source Flow Rates (L/S) Load Flow Rates (L/S)
Model Minimum Open Minimum Closed
Normal Maximum Minimum Normal Maximum
Loop Loop
06 0.25 0.30 0.45 0.60 0.25 0.45 0.60
08 0.30 0.50 0.65 0.75 0.30 0.65 0.75
12 0.50 0.75 1.00 1.10 0.50 1.00 1.10
17 0.65 0.90 1.20 1.30 0.60 1.20 1.30
2/14/12

Thermistor Resistance
Thermistor Temperature (°C) Resistance (Ohms)
26.0 9,230 - 10,007
25.3 9,460 - 10,032
24.7 9,690 - 10,580
24.2 9,930 - 10,840
0.8 30,490 - 32,080
0.3 31,370 - 33,010
-0.3 32,270 - 33,690
-0.8 33,190 - 34,940
-16.9 79,110 - 83,750
-17.5 81,860 - 86,460
-17.8 82,960 - 87,860

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NSKW INSTALLATION MANUAL

Operating Parameters
Heating Mode
Entering Entering Suction Discharge Superheat Subcooling
Load Temp (°C) Source Temp (°C) Pressure (kPa) Pressure (kPa) (°C) (°C)
-15 358-462 1344-1565 4-9 3-8
0 462-565 1434-1620 4-8 3-8
15 10 655-779 1489-1689 4-8 3-7
20 855-993 1551-1758 4-11 3-8
30 986-1151 1586-1896 8-14 4-7
-15 372-476 1951-2179 4-9 4-8
0 476-579 2020-2227 6-7 4-10
25 10 676-862 2082-2310 7-8 4-9
20 834-1020 2144-2386 8-10 4-9
30 993-1234 2199-2503 8-14 4-9
-15 386-490 2544-2792 4-6 3-8
0 531-586 2606-2834 6-7 4-8
35 10 441-869 2675-2930 7-8 4-8
20 848-359 2744-3020 8-10 2-7
30 1020-1317 2813-3116 8-12 2-7
-15 407-510 3137-3413 4-10 2-9
0 510-600 3199-3447 3-9 3-9
50 10 731-883 3268-3551 3-9 3-8
20 862-1076 3344-3654 3-9 2-8
30 operation not recommended
9/26/11

Cooling Mode
Entering Entering Suction Discharge Superheat Subcooling
Load Temp (°C) Source Temp (°C) Pressure (kPa) Pressure (kPa) (°C) (°C)
0 593-683 931-1103 7-12 1-8
10 634-738 1317-1475 6-11 2-8
10 20 676-793 1710-1848 3-8 3-9
30 696-820 2310-2530 3-8 4-9
45 724-841 2930-3206 4-9 6-11
0 614-731 903-1124 8-11 2-3
10 710-862 1338-1538 6-8 3-5
20
20 814-986 1772-1882 6-8 5-7
30 862-1041 2372-2627 4-7 7-8
0 634-779 883-1145 8-11 2-3
10 793-986 1358-1606 6-8 3-5
30
20 889-1089 1834-2027 6-8 5-7
30 1034-1158 2441-2723 4-7 7-8
0 662-834 862-1172 31-36 1-11
10 876-1110 1379-1675 23-29 2-4
45
20 1089-1379 1896-2172 12-21 4-11
30 operation not recommended

9/26/11
NOTE: Operating parameters based on normal conditions with 0.19 L/s per kW output for the load and source.

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 NSKW INSTALLATION MANUAL

Antifreeze Correction
Catalog performance can be corrected for antifreeze use. Please use the following table and note the example given.

Antifreeze % Heating Cooling Pressure

Antifreeze Type
by wt Load Source Load Source Drop
EWT - °C 26.7 -1.1 10.0 32.2 -1.1
Water 0 1.000 1.000 1.000 1.000 1.000
10 0.990 0.973 0.976 0.991 1.075
20 0.978 0.943 0.947 0.979 1.163
Ethylene Glycol 30 0.964 0.917 0.921 0.965 1.225
40 0.953 0.890 0.897 0.955 1.324
50 0.942 0.865 0.872 0.943 1.419
10 0.981 0.958 0.959 0.981 1.130
20 0.967 0.913 0.921 0.969 1.270
Propylene Glycol 30 0.946 0.854 0.869 0.950 1.433
40 0.932 0.813 0.834 0.937 1.614
50 0.915 0.770 0.796 0.922 1.816
10 0.986 0.927 0.945 0.991 1.242
20 0.967 0.887 0.906 0.972 1.343
Ethanol 30 0.944 0.856 0.869 0.947 1.383
40 0.926 0.815 0.830 0.930 1.523
50 0.907 0.779 0.795 0.911 1.639
10 0.985 0.957 0.962 0.986 1.127
20 0.969 0.924 0.929 0.970 1.197
Methanol 30 0.950 0.895 0.897 0.951 1.235
40 0.935 0.863 0.866 0.936 1.323
50 0.919 0.833 0.836 0.920 1.399

WARNING: Gray area represents antifreeze concentrations greater than 35% by weight and should
be avoided due to the extreme performance penalty they represent.

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NSKW INSTALLATION MANUAL

Troubleshooting Guideline for Refrigerant Circuit

The chart below will assist in determining if measurements taken at the unit are within factory specifications and aid in
accurate diagnosis (SYMPTOM) and repair. The chart is general in nature and represents whether a symptom would result in
normal, high, or low readings from the typical operating range.

Water (Loop)
Head Suction Compressor
Symptom Superheat Subcooling Temperature
Pressure Pressure AMP Draw
Differential
Under Charged System (Possible Leak) Low Low Low High* Low Low
Over Charged System High High High Normal High Normal
Low Air Flow Heating High High High* High/Normal Low Low
Low Air Flow Cooling Low Low Low Low/Normal High Low
Low Water Flow Heating Low/Normal Low/Normal Low Low High High
Low Water Flow Cooling High High High High* Low High
High Air Flow Heating Low Low Low Low High Low
High Air Flow Cooling Low High Normal High* Low Normal
High Water Flow Heating Normal Low Normal High* Normal Low
High Water Flow Cooling Low Low Low Low High Low
Low Indoor Air Temperature Heating Low Low Low Normal High Normal/High
Low Indoor Air Temperature Cooling Low Low Low Normal/Low High Low
High Indoor Air Temperature Heating High High High Normal/High* Normal/Low Normal
High Indoor Air Temperature Cooling High High High High* Low High
Restricted TXV High Low Normal/Low High* High Low
Insufficient Compressor (Possible Bad Values) Low High Low High* Normal/High Low
TXV - Bulb Loss of Charge High Low Low High* High Low
Scaled Coaxial Heat Exchange Heating Low Low Low Normal/Low High Low
Scaled Coaxial Heat Exchanger Cooling High High High Normal/Low Low Low
Restricted Filter Drier Check temperature difference (delta T) across filter drier
* Superheat will be high with high evaporator temperatures.

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 NSKW INSTALLATION MANUAL

Heating Cycle Analysis

______kPa = ______SAT°C

______°C

Suction

RV Compressor

Load Source Discharge

Coax Coax

FD ______kPa = ______SAT°C

______°C

______°C Liquid Line

Entering Source Water °C

Entering Water Pressure kPa
Leaving Source Water °C

Unit Amp Draw Leaving Water Pressure kPa

Line Voltage Entering Load Water °C

Loop: Open Closed Entering Load Water Pressure kPa
Subcooling Leaving Load Water °C
Superheat Leaving Load Water Pressure kPa

NOTE: Do not attach refrigerant gauges unless a problem is suspected!

Cooling Cycle Analysis

______kPa = ______SAT°C

______°C

Suction

RV Compressor

Load Source Discharge

Coax Coax

FD ______kPa = ______SAT°C

______°C

______°C Liquid Line

Entering Source Water °C

Entering Water Pressure kPa
Leaving Source Water °C
Leaving Water Pressure kPa
Unit Amp Draw
Line Voltage Entering Load Water °C
Loop: Open Closed Entering Load Water Pressure kPa
Subcooling Leaving Load Water °C
Superheat Leaving Load Water Pressure kPa

NOTE: Do not attach refrigerant gauges unless a problem is suspected!

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NSKW INSTALLATION MANUAL

Startup and Troubleshooting Form

Company Name: _________________________________ Company Phone No: ______________________________
Technician Name: ________________________________ Date: __________________________________________
Model No: ______________________________________ Serial No:_______________________________________
Owner’s Name: __________________________________ Open or Closed Loop: _____________________________
Installation Address: ______________________________ Installation Date: _________________________________

Check One
T Start up/Check-out for new installation T Troubleshooting Problem:___________________________________

1. FLOW RATE IN L/s (SOURCE SIDE HEAT EXCHANGER)

Water In Pressure: a.______ kPa
Water Out Pressure: b.______ kPa
Pressure Drop = a - b c.______ kPa
Convert Pressure Drop to Flow Rate
(refer to Pressure Drop table) d.______ L/s

2. TEMPERATURE RISE OR DROP ACROSS SOURCE SIDE HEAT EXCHANGER

COOLING HEATING
Water In Temperature: e.______ °C e.______ °C
Water Out Temperature: f. ______ °C f. ______ °C
Temperature Difference: g.______ °C g.______ °C

3. TEMPERATURE RISE OR DROP ACROSS LOAD SIDE HEAT EXCHANGER

COOLING HEATING
Water In Temperature: h.______ °C h.______ °C
Water Out Temperature: i. ______ °C i. ______ °C
Temperature Difference: j. ______ °C j. ______ °C

4. HEAT OF REJECTION (HR) / HEAT OF EXTRACTION (HE) CALCULATION

HR or HE = Flow Rate x Temperature Difference x Brine Factor*
d. (above) x g. (above) x 4.1 for Methanol or Environol, 4.2 for water*
Heat of Extraction (Heating Mode) = kW/hr
Heat of Rejection (Cooling Mode) = kW/hr
Compare results to Capacity Data Tables
Note: Steps 5 through 8 need only be completed if a problem is suspected

5. WATTS
COOLING HEATING HYDRONIC
Volts: m._____ VOLTS m.______ VOLTS m. ______ VOLTS
Total Amps (Comp. + Fan): n. _____ AMPS n. ______ AMPS n. ______ AMPS
Watts = m. x n. x 0.85 o. _____ WATTS o. ______ WATTS o. ______ WATTS

6. CAPACITY
Cooling Capacity = HR. - o. p. _____ kW/hr
Heating Capacity= HE. + o. p. _____ kW/hr

7. EFFICIENCY
Cooling EER = p. / o. q. _____ COP
Heating COP = p. / o. q. _____ COP

8. SUPERHEAT (S.H.) / SUBCOOLING (S.C.)

COOLING COOLING HEATING HYDRONIC
Suction Pressure: r. ______ kPa r. ______ kPa r. ______ kPa
Suction Saturation Temperature: s. ______ °C s. ______ °C s. ______ °C
Suction Line Temperature: t. ______ °C t. ______ °C t. ______ °C
Superheat = t. - s. u. _____ °C u. ______ °C u. ______ °C

Head Pressure: v. ______ kPa v. ______ kPa v. ______ kPa

High Pressure Saturation Temp.: w. _____ °C w. _____ °C w. _____ °C
Liquid Line Temperature*: x. ______ °C x. ______ °C x. ______ °C
Subcooling = w. - x. y. ______ °C y. ______ °C y. ______ °C
* Note: Liquid line is between the source heat exchanger and the expansion valve in the cooling mode;
between the load heat exchanger and the expansion valve in the heating mode.

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 NSKW INSTALLATION MANUAL

Troubleshooting
Should a major problem develop, refer to the following 9. The internal winding of the compressor motor may be
information for possible causes and corrective steps: grounded to the compressor shell. If so, replace the
compressor.
Compressor Won’t Run 10. The compressor winding may be open. Check continuity
with an ohm meter. If the winding is open, replace the
1. The fuse may be blown or the circuit breaker is open.
compressor.
Check electrical circuits and motor windings for shorts
or grounds. Investigate for possible overloading.
Replace fuse or reset circuit breakers after the fault is Insufficient Cooling or Heating
corrected. 1. Check aquastat for improper location (secondary mode
2. Supply voltage may be too low. Check voltage with a only).
volt meter. 2. Check for restriction in water flow.
3. Remote control system may be faulty. Check aquastat 3. Check subcooling for low refrigerant charge.
for correct wiring, setting and calibration. Check 24-volt 4. The reversing valve may be defective and creating a
transformer for burnout. bypass of refrigerant. If the unit will not cool, check the
4. Wires may be loose or broken. Replace or tighten. reversing valve coil.
5. The low pressure switch may have tripped due to one or 5. Check thermal expansion valve for possible restriction of
more of the following: refrigerant flow.
a. Fouled or plugged coaxial heat exchangers
b. Low or no water flow (source side heating, load Noisy Unit Operation
side cooling)
1. Check compressor for loosened mounting bolts. Make
c. Water too cold (source side heating)
sure compressor is floating free on its isolator mounts.
d. Low refrigerant
2. Check for tubing contact with the compressor or other
6. The high pressure switch may have tripped due to one
surfaces. Readjust it by bending slightly.
or more of the following:
3. Check screws on all panels.
a. Fouled or plugged coaxial heat exchanger
4. Check for chattering or humming in the contactor or
b. Low or no water flow (source side cooling, load
relays due to low voltage or a defective holding coil.
side heating)
Replace the component.
c. Water too warm (source side cooling)
5. Check for proper installation of vibration absorbing
7. Check the capacitor (Single Phase only).
material under the unit. Unit must be fully supported,
8. The compressor overload protection may be open. If
not just on corners.
the compressor dome is extremely hot, the overload will
6. Check for abnormally high discharge pressures.
not reset until cooled down. If the overload does not
reset when cool, it may be defective. If so, replace the
compressor.

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NSKW INSTALLATION MANUAL

Troubleshooting cont.
Troubleshooting Controls Check the jumpers on the control board:
Check the unit. If a lockout mode is displayed, refer to the 1. Refer to the Control Board with Jumper illustration in
table below to determine the meaning of the failure. Follow the Converting to a Dedicated Cooling Unit section to
the procedure listed to correct the problem. see the location of the jumper on the board. If the unit is
a heating only unit, the jumper should be across 1 and 2.
2. If the unit is a cooling only unit, the jumper should be
Check the mode:
across 2 and 3.
1. If the unit is running on the internal aquastat, verify the
3. If the unit is a reversible unit, the jumper should be
unit is in “Primary” mode. The SL should be set to 0 in
across 3 and 4.
the setup menu.
2. If the unit is running on an external aquastat, the SL
should be set to 1. Check the thermistor calibration:
1. Using a thermometer in the P/T port, check the
incoming water temperature.
2. Verify that the measured temperature is within 3
degrees of the temperature displayed on the unit.
3. If it is not, adjust the calibration in the setup menu.

Standard Control Diagnostic Table

DISPLAY FAILURE DIAGNOSTIC
DC Freeze detection thermistor is closed (shorted) Replace the freeze detection thermistor (clip-on
thermistor)
DO Freeze detection thermistor is open Verify that the freeze detection thermistor is
secured properly in the board connector. If the
connection is secure, replace the thermistor.
FP Freeze detection The water going through the unit has reached the
freeze point setting (P=5, CL=15, OL=30). Verify
that the freeze detection setting is correct for the
application.
HC Water set point thermistor is closed (shorted) Replace the water set point thermistor (threaded
thermistor).
HP High Pressure The unit has cut out on high pressure. Discharge
pressure is >4.1 kPa.
LP Low Pressure The unit has cut out on low pressure. Suction
pressure is <275 Pa.
PO Water set point thermistor is open Verify that the water set point thermistor is
properly secured in the board connector. If the
connection is secure, replace the thermistor.

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 NSKW INSTALLATION MANUAL

Preventive Maintenance
1. Keep all air out of the water lines. An open loop system 4. Connect a plastic hose from the circulating pump inlet
should be checked to ensure that the well head is not to the bottom of a plastic five (5) gallon pail (refer to
allowing air to infiltrate the water line. Lines should the Cleaning Connections illustration).
always be airtight. 5. Connect a plastic hose from the inlet line of the water-
2. Keep the system under pressure at all times. In open to-refrigerant heat exchanger to the plastic pail. Secure
loop systems, it is recommended that a water control tightly to ensure that circulating solution does not spill
valve be placed in the discharge line to prevent loss of (refer to the Cleaning Connections illustration).
pressure during off cycles. Closed loop systems must 6. Partially fill the plastic pail with clear water (about two-
have a positive static pressure. thirds full) and prime the circulating pump. Circulate
until lines are full.
NOTES: If the installation is performed in an area with 7. Start the circulating pump and slowly add a commercial
a known high mineral content in the water, it is best to scale remover* to the water as recommended by the
establish a periodic maintenance schedule to check the scale remover manufacturer’s directions.
water-to-refrigerant heat exchanger on a regular basis. 8. Be sure the pump circulation is opposite to the normal
Should periodic cleaning be necessary, use standard water flow through the water-to-refrigerant heat
cleaning procedures which are compatible with either the exchanger.
cupronickel or copper water lines. Generally, the more water 9. Maintain re-circulation until all scale and other material
flowing through the unit, the less chance there is for scaling. has been dissolved and flushed from the heat exchanger.
Low flow rates produce higher temperatures through the 10. Upon completion of the procedure. Safely dispose of the
coil. To avoid excessive pressure drop and the possibility of solution.
copper erosion, do not exceed flow rate as shown on the 11. Rinse the pump and plastic pail. Refill with clear water.
specification sheets for each unit. 12. Start the pump circulation and flush the system until all
acid residue has been removed from the system. Refill
Cleaning Procedure the plastic pail until only clear water is circulated.
13. Turn off the circulating pump and disconnect all hoses
1. Close the inlet and outlet water valves to isolate the heat
and fittings.
pump from the well system, water heater or loop pumps.
14. Replace solenoid valves, pumps, hoses and other
2. Disconnect piping and remove solenoid valve, pumps,
devices in their original locations. On closed loop
etc, from the inlet and outlet connections on the heat
systems, be sure to purge between the flow center and
pump.
unit to avoid getting air into the loop.
3. Connect plastic hoses from the circulating pump to the
15. Put the heat pump back into operation. Check for
outlet of the water-to-refrigerant heat exchanger to be
proper operating temperature.
de-limed (refer to the Cleaning Connections illustration).

Cleaning Connections

Five-gallon Bucket

Pump
WARNING: This process involves a caustic
solution and may be harmful to people and
animals. Wear protective equipment (glasses,
rubber gloves, apron, etc.)

NOTE: *Virginia Chemical Co. makes a liquid ice machine cleaner which should be used on water-to-refrigerant heat
exchangers serving a domestic hot water system. Calci-Solve by NYCO is available for use on other heat exchangers

45
NSKW INSTALLATION MANUAL

Service Parts
Part Description 06 08 12 17
Compressor 220-240/50/1 34P583-02 34P621-02 34P580-02 34P614-02
380-420/50/3 34P583-04 34P621-04 34P580-04 34P614-04
Refrigeration Components

Compressor Capacitor 220-240/50/1 16P002D20 16P002D36 16P002D39 16P002D36

Compressor Sound Jacket 92P504A05 92P519-01 92P519-02 92P519-02
Thermal Expansion Valve 33P605-18 33P605-10 33P605-17 33P605-17
Filter Drier for ‘Reversible Models’ 36P500B01 36P500B01 36P500B02 36P500B02
Reversing Valve with Coil 33P506-04 33P503-05 33P526-04 33P526-04
Hot Water Generator Coil n/a 62I516-03 62I516-03 62I516-03
Source Coaxial Heat Exchanger (copper) 62I573-01 62I574-01 62I543-04 62I557-01
Source Coaxial Heat Exchanger (cupronickel) 62I573-02 62I574-02 62I543-03 62I557-02
Load Coaxial Heat Exchanger (copper) 62I573-01 62I574-01 62I543-04 62I557-01
Load Coaxial Heat Exchanger (cupronickel) 62I573-02 62I574-02 62I543-03 62I557-02
DHW Load Coax Vented Double Wall (copper) 62P549-01 n/a n/a n/a
Safeties / Sensors

High Pressure Switch 35P506B02 35P506B02 35P506B02 35P506B02

Low Pressure Switch 35P506B01 35P506B01 35P506B01 35P506B01
Water Temperature Sensor for Standard Control
12P541-01 12P541-01 12P541-01 12P541-01
Board
Freeze Detection Sensor for Standard Control
12P505-05 12P505-05 12P505-05 12P505-05
Board
Compressor Contactor - Single Phase 13P004A03 13P004A03 13P004A03 13P004A03
Compressor Contactor - Three Phase 13P537B03 13P537B03 13P537B03 13P537B03
Transformer - 220-240v 15P501-02 15P501-02 15P501-02 15P501-02
Transformer - 380-420v 15P511-02 15P511-02 15P511-02 15P511-02
Connection Block - 3 Position 12P503-06 12P503-06 12P503-06 12P503-06
Connection Block - 12 Position 12P503-07 12P503-07 12P503-07 12P503-07
Connection Block - 12 Position Double Tab 12P528B01 12P528B01 12P528B01 12P528B01
Control Touch Screen 19S561-02 19S561-02 19S561-02 19S561-02
Electrical

Standard Control Board 17P549-04 17P549-04 17P549-04 17P549-04

FX10 Control Board w/ Harness 17S51606-00 17S51606-00 17S51606-00 17S51606-00
FX10 Communication Card - Open N2 17P516-08 17P516-08 17P516-08 17P516-08
FX10 Communication Card - Lonworks 17P516-09 17P516-09 17P516-09 17P516-09
FX10 Communication Card - Backnet 17P516-10 17P516-10 17P516-10 17P516-10
MUI - Medium User Interface 19P580-01 19P580-01 19P580-01 19P580-01
MUI Card 17P516-11 17P516-11 17P516-11 17P516-11
IntelliStart Soft Starter
IntelliStart Power Block 12P546-01 12P546-01 12P546-01 12P546-01
Grounding Lug 12P004A 12P004A 12P004A 12P004A
Rear Access Panel 40F749-01 40F749-01 40F749-01 40F749-01
Cabinet

Front Access Panel without MUI 40F749-01 40F749-01 40F749-01 40F749-01

Front Access Panel with MUI 40F749-02 40F749-02 40F749-02 40F749-02
Front Plastic Access Panel 40P542-50 40P542-50 40P542-50 40P542-50
Top Panel 42P557-01W 42C544-01 42C544-01 42C544-01
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 NSKW INSTALLATION MANUAL

Technical Documentation
Model NSKW06
Air-water
Exhaust-water
Type of heat pump
Brine-water
Water-water
Low-temperature heat pump Yes No Yes No
Integrated immersion heater for additional heat Yes No
Heat pump combination heater Yes No Yes No
Climate Average Cold Warm
Temperature application Average (55°C) Low (35°C)
Applied standards EN-14825

Rated heat output Prated 5.27 kW Seasonal space heating energy efficiency nc 119 %

Declared capacity for space heating at part load and at outdoor Declared coefficient of performance for space heating at part load
temperature Tj and at outdoor temperature Tj

Tj = -7 °C Pdh 5.34 kW Tj = -7 °C COPd 2.66

Tj = +2 °C Pdh 5.55 kW Tj = +2 °C COPd 3.16
Tj = +7 °C Pdh 5.68 kW Tj = +7 °C COPd 3.54
Tj = +12 °C Pdh 5.81 kW Tj = +12 °C COPd 4.01
Tj = biv Pdh 5.27 kW Tj = biv COPd 2.50
Tj = TOL Pdh 5.27 kW Tj = TOL COPd 2.50
Tj = -15 °C (if TOL < -20 °C) Pdh - kW Tj = -15 °C (if TOL < -20 °C) COPd -

Bivalent temperature Tbiv -10 °C Min. outdoor air temperature TOL -10 °C
Cycling interval capacity Pcych - kW Cycling interval efficiency COPcyc - -
Degradation coefficient Cdh 1.00 - Max supply temperature WTOL 55.0 °C
Power consumption in modes other than active mode Additional heat Additional heat
Off mode POFF 0.010 kW Rated heat output Psup - kW
Thermostat-off mode PTO 0.005 kW
Standby mode PSB 0.002 kW Type of energy input Electric
Crankcase heater mode PCK - kW
Other items
Capacity control Fixed Rated airflow (air-water) - m3/h
Sound power level, indoors/outdoors LWA 57/0 dB Nominal heating medium flow 1.26 m3/h
Brine flow brine-water or water-water
Annual energy consumption QHE 3432 kWh 1.62 m3/h
heat pumps
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NSKW INSTALLATION MANUAL

Technical Documentation cont.

Model NSKW08
Air-water
Exhaust-water
Type of heat pump
Brine-water
Water-water
Low-temperature heat pump Yes No Yes No
Integrated immersion heater for additional heat Yes No
Heat pump combination heater Yes No Yes No
Climate Average Cold Warm
Temperature application Average (55°C) Low (35°C)
Applied standards EN-14825
Rated heat output Prated 7.71 kW Seasonal space heating energy efficiency nc 132 %
Declared coefficient of performance for space heating at part load
Declared capacity for space heating at part load and at outdoor temperature Tj
and at outdoor temperature Tj
Tj = -7 °C Pdh 7.81 kW Tj = -7 °C COPd 2.92
Tj = +2 °C Pdh 8.13 kW Tj = +2 °C COPd 3.48
Tj = +7 °C Pdh 8.33 kW Tj = +7 °C COPd 3.90
Tj = +12 °C Pdh 8.52 kW Tj = +12 °C COPd 4.42
Tj = biv Pdh 7.71 kW Tj = biv COPd 2.75
Tj = TOL Pdh 7.71 kW Tj = TOL COPd 2.75
Tj = -15 °C (if TOL < -20 °C) Pdh - kW Tj = -15 °C (if TOL < -20 °C) COPd -

Bivalent temperature Tbiv -10 °C Min. outdoor air temperature TOL -10 °C
Cycling interval capacity Pcych - kW Cycling interval efficiency COPcyc - -
Degradation coefficient Cdh 1.00 - Max supply temperature WTOL 55.0 °C
Power consumption in modes other than active mode Additional heat Additional heat
Off mode POFF 0.010 kW Rated heat output Psup - kW
Thermostat-off mode PTO 0.005 kW
Standby mode PSB 0.007 kW Type of energy input -
Crankcase heater mode PCK - kW
Other items
Capacity control Fixed Rated airflow (air-water) - m3/h
Sound power level, indoors/outdoors LWA 57/0 dB Nominal heating medium flow 1.80 m3/h
Brine flow brine-water or water-water
Annual energy consumption QHE 4543 kWh 2.34 m3/h
heat pumps

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48
 NSKW INSTALLATION MANUAL

Technical Documentation cont.

Model NSKW12
Air-water
Exhaust-water
Type of heat pump
Brine-water
Water-water
Low-temperature heat pump Yes No Yes No
Integrated immersion heater for additional heat Yes No
Heat pump combination heater Yes No Yes No
Climate Average Cold Warm
Temperature application Average (55°C) Low (35°C)
Applied standards EN-14825
Rated heat output Prated 11.14 kW Seasonal space heating energy efficiency nc 137 %
Declared coefficient of performance for space heating at part load
Declared capacity for space heating at part load and at outdoor temperature Tj
and at outdoor temperature Tj
Tj = -7 °C Pdh 11.22 kW Tj = -7 °C COPd 3.01
Tj = +2 °C Pdh 11.46 kW Tj = +2 °C COPd 3.58
Tj = +7 °C Pdh 11.60 kW Tj = +7 °C COPd 4.03
Tj = +12 °C Pdh 11.74 kW Tj = +12 °C COPd 4.60
Tj = biv Pdh 11.14 kW Tj = biv COPd 2.86
Tj = TOL Pdh 11.14 kW Tj = TOL COPd 2.86
Tj = -15 °C (if TOL < -20 °C) Pdh - kW Tj = -15 °C (if TOL < -20 °C) COPd -

Bivalent temperature Tbiv -10 °C Min. outdoor air temperature TOL -10 °C
Cycling interval capacity Pcych - kW Cycling interval efficiency COPcyc - -
Degradation coefficient Cdh 1.00 - Max supply temperature WTOL 55.0 °C
Power consumption in modes other than active mode Additional heat Additional heat
Off mode POFF 0.010 kW Rated heat output Psup - kW
Thermostat-off mode PTO 0.005 kW
Standby mode PSB 0.007 kW Type of energy input -
Crankcase heater mode PCK - kW
Other items
Capacity control Fixed Rated airflow (air-water) - m3/h
Sound power level, indoors/outdoors LWA 57/0 dB Nominal heating medium flow 2.70 m3/h
Brine flow brine-water or water-water heat
Annual energy consumption QHE 6343 kWh 3.60 m3/h
pumps
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49
NSKW INSTALLATION MANUAL

Technical Documentation cont.

Model NSKW17
Air-water
Exhaust-water
Type of heat pump
Brine-water

Water-water

Low-temperature heat pump Yes No Yes No

Integrated immersion heater for additional heat Yes No
Heat pump combination heater Yes No Yes No

Climate Average Cold Warm

Temperature application Average (55°C) Low (35°C)

Applied standards EN-14825
Rated heat output Prated 15.62 kW Seasonal space heating energy efficiency nc 126 %
Declared coefficient of performance for space heating at part
Declared capacity for space heating at part load and at outdoor temperature Tj
load and at outdoor temperature Tj
Tj = -7 °C Pdh 16.06 kW Tj = -7 °C COPd 2.82
Tj = +2 °C Pdh 16.52 kW Tj = +2 °C COPd 3.30
Tj = +7 °C Pdh 16.80 kW Tj = +7 °C COPd 3.66
Tj = +12 °C Pdh 17.08 kW Tj = +12 °C COPd 4.09
Tj = biv Pdh 15.93 kW Tj = biv COPd 2.70
Tj = TOL Pdh 15.93 kW Tj = TOL COPd 2.70
Tj = -15 °C (if TOL < -20 °C) Pdh - kW Tj = -15 °C (if TOL < -20 °C) COPd -

Bivalent temperature Tbiv -10 °C Min. outdoor air temperature TOL -10 °C
Cycling interval capacity Pcych - kW Cycling interval efficiency COPcyc - -
Degradation coefficient Cdh 1.00 - Max supply temperature WTOL 55.0 °C
Power consumption in modes other than active mode Additional heat Additional heat
Off mode POFF 0.010 kW Rated heat output Psup - kW
Thermostat-off mode PTO 0.005 kW
Standby mode PSB 0.007 kW Type of energy input -
Crankcase heater mode PCK - kW
Other items
Capacity control Fixed Rated airflow (air-water) - m3/h
Sound power level, indoors/outdoors LWA 63/0 dB Nominal heating medium flow 3.24 m3/h
Brine flow brine-water or water-water
Annual energy consumption QHE 9656 kWh 4.32 m3/h
heat pumps
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50
Revision Table
Pages: Description: Date: By:
Mult. Added Energy Labelling and Technical Documentation 18 Mar 2016 MA
All Updated Nomenclature, Electric Heating Data, Service Parts List and Physical Data 05 May 2015 MA
All Revision table added 05 May 2015 MA
Manufactured by
WaterFurnace International, Inc.
9000 Conservation Way
Fort Wayne, IN 46809
www.waterfurnace.com

Product: Envision NSKW

Type: Geothermal Hydronic Heat Pump - 50 Hz
Size: 06-17 kW
Document: Installation Manual

©2016 WaterFurnace International, Inc., 9000 Conservation Way, Fort Wayne, IN 46809-9794. WaterFurnace has a policy
of continual product research and development and reserves the right to change design and specifications without notice. IM1066WN 03/16