09DK054-094/30GN,GT,GU040-420

38AH024-134
Accessory Low Ambient Operation
MotormasterT III Control
50/60 Hz

Installation Instructions
Part No. 30GT910079

CONTENTS SAFETY CONSIDERATIONS

Page
Installation, start-up, and servicing of this equipment can
GENERAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 be hazardous due to system pressures, electrical compo-
SAFETY CONSIDERATIONS . . . . . . . . . . . . . . . . . . . 1 nents, and equipment location (roofs, elevated structures, etc.)
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,2
Before Installing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Only trained, qualified installers and service technicians
should install, start up, and service this equipment.
APPLICATION NOTES . . . . . . . . . . . . . . . . . . . . . . . . 3
Winter Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 When working on this equipment, observe precautions in
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-29 the literature and on tags, stickers, and labels attached to the
Step 1 — Install Field-Fabricated equipment and any other safety precautions that may apply.
Wind Baffles and Brackets . . . . . . . . . . . . . . . . . . 4
Step 2 — Install Motormaster III Controls . . . . . 10
Step 3 — Make Electrical Connections . . . . . . . 18
• 09DK054,064/30GN,GT,GU040-050/38AH044-064 Open all remote disconnects before servicing this equip-
• 09DK074-094/30GN,GT,GU060-090 AND ment. Electrical shock could result in personal injury.
ASSOCIATED MODULAR UNITS/
38AH074-104
• 30GN,GT,GU100,110 AND ASSOCIATED INTRODUCTION
MODULAR UNITS
• 30GN,GT,GU130-210 AND ASSOCIATED The Motormaster III control is a motor speed control de-
MODULAR UNITS vice which adjusts condenser fan motor speed in response to
• 38AH024-034 UNITS declining liquid refrigerant temperatures. A properly applied
• 09DK054-094 UNITS WITH 100% SINGLE Motormaster III control extends the operating range of air-
CIRCUIT CONDENSER, 38AH044-084 conditioning systems and permits operation at lower out-
UNITS WITH FACTORY-INSTALLED door ambient temperatures.
SINGLE-CIRCUITING, AND MODULES
124A/B, 134A/B On 09DK units, the Motormaster III control is used in con-
• ALL 575-V UNITS junction with the standard fan cycling controls. See
START-UP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Table 2A or 2B for the ambient temperatures at which the
09DK units operate without modification.
TROUBLESHOOTING . . . . . . . . . . . . . . . . . . . . . . . . 30
Table 2A — Minimum Outdoor-Air Operating
Temperature — 09DK (English)
GENERAL
This book contains instructions for the installation, start- COMPRESSOR CAPACITY
up, and service of the Motormaster III control on Models HEAD (%)*
UNIT TD
09DK, 30G, and 38AH. The 30GN,GT,GU230-420 units are 09DK PRESSURE 100 75 50 25
shipped as 2 separate modules. See Table 1 for details of CONTROL (F) Minimum Outdoor-Air Temperature
modular combinations. (F)
054, FCPSs 30 29 34 38 51
25 38 40 42 53
Table 1 — 30GN,GT,GU080-210 and 064 (2 Fans)† 20 47 47 46 56
Associated Modular Units FCPSs 30 12 19 22 43
074- (2 Fans)† 25 22 25 29 47
UNIT ASSOCIATED UNIT MODULES 094 ATSs
30GN,GT,GU 30GN,GT,GU (2 Fans) 20 31 31 36 51
080 230B
090 245B NOTE: See Legend and Notes on page 2.
100 255B, 270B
110 290B, 315B
130 None
150 230A-255A
170 270A, 330A/B, 360B (50 Hz)
190 290A, 360A, 360B (60 Hz), 390B
210 315A, 390A, 420A/B

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 2 2 PC 111 Catalog No. 533-087 Printed in U.S.A. Form 30GT-52SI Pg 1 11-98 Replaces: 30GT-40SI
Tab 3a 4a 5c
 Table 2B — Minimum Outdoor-Air Operating • 09DK054-094 units with 100% condenser coil circuiting
Temperature — 09DK (SI) require only one control
• 38AH124,134 modular units require 2 controls (one per
COMPRESSOR CAPACITY (%)*
HEAD modular unit)
UNIT PRESSURE TD 100 75 50 25
09DK CONTROL (C) Minimum Outdoor-Air
Temperature (C)
054, FCPSs 16.7 −2 1 3 11 To avoid the possibility of electrical shock, open all dis-
064 (2 Fans)† 13.9 3 4 6 12 connects before installing or servicing this accessory.
11.1 8 8 8 13
FCPSs 16.7 −11 −7 −6 6
074- (2 Fans)† Before Installing — Inspect the contents of this acces-
094 ATSs 13.9 −6 −4 −2 8 sory package before installing. File a claim with the shipper
(2 Fans) 11.1 −1 −1 2 11 if you find shipping damage or if a part is missing.
LEGEND
Table 4 — Motormaster III Control Package
ATS — Air Temperature Switch Contents
FCPS — Fan Cycling Pressure Switch
TD — Temperature Difference (Saturated Condensing
Temperature Entering − Entering-Air Temperature) QUANTITY ITEM PART NO.
*Interpolation permitted. 1 Control HR46GN001
†Additional FCPSs needed for 67/33%, 33/33/33%, and 1 Sensor 30GT/GU412176
33/33/17/17% capacity. 4 Screw AL79AU216
NOTES:
1. Fans on the 09DK054-094 units are controlled by ATSs and FCPSs. Table 5 — Applicable Voltages and Motors
2. Minimum outdoor temperatures are determined for indoor and out-
door unit combinations of the same capacity. MOTOR
UNIT NAMEPLATE (FACTORY INSTALLED)
Table 3 shows the ambient temperature at which VOLTAGE* PART NO.
30G/38AH units operate without modification. 208/230-3-60 HD52AK652
380-3-60 HD52AK346
Table 3 — Minimum Outdoor-Air Operating 460-3-60 HD52AK652
Temperature — 30G/38AH 575-3-60† HD52AK652
230-3-50 HD52AK652
346-3-50 HD52AK346
TEMPERATURE 380/415-3-50 HD52AK652**
UNIT/SIZE
F C 380/415-3-50 HD52AK653††
30GN,GT,GU040-210 0 −18.0 *Not all voltages are available for all units. See base installation
30GN,GT,GU Modules 230-420 0 −18.0 instructions for available voltages.
024 53 11.7 †Requires special autotransformer circuit for each Motormaster III
028 50 10.0 control. Two transformers (Carrier Part No. HT01AH851) are re-
034 49 9.4 quired for each control.
044 50 10.0 **38AH, 09DK only.
054 48 8.0 ††30GN,GT,GU 380/415-3-50 units require motor changeout. Re-
064 39 3.9 place factory-installed motor with HD52AK652. See Fig. 12-14 for
38AH* 074 31 −0.5 motor locations.
084 20 −6.7
094 25 −3.9
104 14 −10.0
124 38 3.3
134 38 3.3
*Data based on standard units operating at 100% of system capacity.
Temperatures shown are for circuit A or B, whichever is higher.

To operate these units below the ambient temperatures listed,

Motormastert III controls (Fig. 1) must be added. Field-
supplied and installed wind baffles are also required for all
units except 38AH024-034 units. The Motormaster III con-
trol permits operation of the unit to an ambient temperature
of −20 F (−29 C). The control regulates the speed of 3-phase
fan motors that are compatible with the control. These mo-
tors are installed at the factory.
See Table 4 for the Motormaster III control accessory pack-
age contents and Table 5 for applicable voltages and motors.
Replacement of motor or fan blade on most units is not nec-
essary since the control is compatible with the factory-
installed fan motors. Only field wiring control is required.
There is an exception with unit 30GN,GT,GU
380/415-3-50. Motor replacement for this unit is required.
See Table 5 for applicable motor.
NOTE: Two Motormaster III controls must be added for each
unit (one for each circuit) with the following exceptions:
• 30GN,GT,GU230-420 modular units require 4 controls
(2 per modular unit)
• 38AH024-034 units require only one control
Fig. 1 — Motormaster III Control
• 38AH044-084 units with optional single circuiting require
only one control
2
 APPLICATION NOTES Table 6B — Minimum Capacity Step (%) —
For the 09DK units, the information in this book is 30GN,GT,GU — 50 Hz
applicable when either 100% or 50/50% condenser coil cir- STANDARD
cuiting is used. UNIT/SIZE STANDARD UNIT WITH
NOTE: If other than 100% or 50/50% coil circuiting is used, 30GN,GT,GU UNIT ACCESSORY
UNLOADER(S)*
an accessory Motormastert III Relay/Sensor kit is required
040 24† 21**
for efficient control. See accessory installation instructions
for more information. 045 31† 18**
050 28† 15**
There are no minimum capacity step (%) tables with the
060 33† 16**
09DK condensers, because capacity steps are dependent on
the compressor-bearing unit. Refer to base unit product data 070 19† 11**
literature for further details. 080; Module 230B 22 8
090; Module 245B 14 7
Corrosion-inhibited antifreeze solution approved for
30G chiller use must be added to the cooler fluid loop to 100; Modules 255B,
270B 13 7
protect it to temperatures 15° F (9° C) below the lowest ex-
110; Modules 290B,
pected outdoor temperature. 315B 17 8
Widely varying cooling loads are often encountered 130 10 6
during low ambient temperature operation of the 30G chiller. 150; Modules 230A,
To minimize compressor cycling as a result of these condi- 245A, 255A 13 6
tions, provide sufficient volume in the chiller fluid loop, add- 170; Modules 270A, 9 5
ing a properly baffled storage tank to the system if neces- 330A/B, 360B
sary. At least 6 gal per ton (6.5 L per kW) of refrigeration is 190; Modules 290A, 17 11
recommended for a moderate system load. 360A, 390B
210; Modules 315A, 9 7
390A, 420A/B
*30GN,GU080-210 and associated modules (see Table 1): Acces-
Operation at low ambient temperature is not rec- sory unloaders available. 30GT080-210 and associated modules
ommended if the minimum load on the 30G chiller or (see Table 1): Accessory unloaders not available.
the 38AH condensing unit is below its minimum step of †A1 compressor with standard unloader, OR
capacity. Unstable operation may result. See Table 6A, A1 compressor with standard unloader and B1 compressor with
accessory unloader.
6B, or 6C. **A1 compressor with standard unloader and accessory unloader, and
B1 compressor with accessory unloader, OR
A1 compressor with standard unloader and accessory unloader, and
B1 compressor with 2 accessory unloaders.
Table 6A — Minimum Capacity Step (%) —
30GN,GT,GU — 60 Hz
Table 6C — Minimum Capacity Step (%) —
STANDARD 38AH — 50/60 Hz
UNIT/SIZE STANDARD UNIT WITH
30GN,GT,GU UNIT ACCESSORY
UNLOADER(S)* OPTIONAL VAV UNIT WITH
UNIT STANDARD ELECTRIC UNLOADERS OR
040 25† — STANDARD UNIT WITH
38AH UNIT ACCESSORY UNLOADER(S)
045 24† 21**
ON LEAD COMPRESSOR
050 31† 20**
024 33 17
060 28† 18**
028 33 17
070 33† 16**
034 28 14
080; Module 230B 22 11
044 25 —
090; Module 245B 18 9
054 21 22
100; Modules 255B, 16 8
270B 064 32 16
110; Modules 290B, 074 29 14
315B 14 7
084 33 17
130 14 8 094 22 22
150; Modules 230A, 11 6 104 18 17
245A, 255A
Modules
170; Modules 270A, 11 6 124A, 124B, 32 9
330A/B 134A
190; Modules 290A, 13 9 Module 134B 29 8
360A/B, 390B
210; Modules 315A, VAV — Variable Air Volume
390A, 420A/B 11 8

*30GN,GU080-210 and associated modules (see Table 1): Acces- Winter Start — All 30GN,GT,GU chillers have winter
sory unloaders available. 30GT080-210 and associated modules start features included in their microprocessor control logic.
(see Table 1): Accessory unloaders not available.
†A1 compressor with standard unloader, OR All 38AH units have winter start features included in their
A1 compressor with standard unloader and B1 compressor with standard controls. The 09DK compressorless condenser sec-
accessory unloader. tions do not need to be directly modified, however, the total
**A1 compressor with standard unloader and accessory unloader, and system may require winter start control. Refer to indoor
B1 compressor with accessory unloader, OR
A1 compressor with standard unloader and accessory unloader, and base unit installation instructions. No additional provisions
B1 compressor with 2 accessory unloaders. are necessary.

3
 INSTALLATION sizes of brackets and baffles required and for bracket and
baffle details. Use 20-gage (1 mm) galvanized sheet metal,
Step 1 — Install Field-Fabricated Wind Baffles or similar corrosion-resistant material for the baffles. Use
14-gage (1.85 mm) galvanized sheet metal or similar corrosion-
and Brackets resistant material for the brackets. Use field-supplied screws
to attach baffles and brackets to unit. Screws should be
1⁄4-in. (6.3 mm) diameter or larger. Drill required screw holes

for mounting baffles and brackets.

To avoid the possibility of electrical shock, open all dis-
connects before installing or servicing this accessory.
Wind baffles and brackets must be field fabricated for all To avoid damage to refrigerant coils and electrical com-
units (except 38AH024-034 units) to ensure proper cool- ponents, use extreme care when drilling screw holes and
ing cycle operation at low-ambient temperatures with screwing in fasteners.
Motormastert III controls. See Fig. 2-10 for the number and

Summary of Baffles and Brackets

BAFFLE TYPE AND QUANTITY BRACKETS*
UNIT Length
A B C D E F QTY
in. mm
09DK054,064 — — — — — 2 6 363⁄8 924
09DK074,084 2 — — — 4 — 8 443⁄8 1127
09DK094 2 4 — — — — 8 443⁄8 1127
30GN,GT,GU040-050 — — — — — 2 6 363⁄8 924
30GN,GT,GU060,070 2 — — — 4 — 8 443⁄8 1127
30GN,GT,GU080,090; Modules 230B,245B 2 4 — — — — 8 443⁄8 1127
30GN,GT,GU100,110; Modules 255B-315B — — 2 4 — — 8 443⁄8 1127
38AH094,104 2 4 — — — — 8 443⁄8 1127
38AH044-064; Modules 124A,124B,134A — — — — — 2 6 363⁄8 924
38AH074,084; Module 134B 2 — — — 4 — 8 443⁄8 1127
*See Fig. 7 for bracket construction.
NOTE: Due to horizontal coil position, brackets and baffles are not required for 38AH024-034 units.

BAFFLE SIZE
BAFFLE
in. mm
A 26 x 4111⁄16 660 x 1059
B 47 x 417⁄8 1194 x 1064
C 32 x 4111⁄16 813 x 1059
D 61 x 417⁄8 1549 x 1064
E 42 x 417⁄8 1067 x 1064
F 85 x 3311⁄16 2159 x 856
NOTES
1. Unit 09DK condensers are not pro-
vided with compressors.
2. See Fig. 3-6 for baffle construction.

09DK054,064/30GN,GT,GU040-050/ 09DK074,084/30GN,GT,GU060,070/
38AH044-064 AND 38AH074,084 AND
MODULES 124A/B,134A MODULE 134B

09DK094/30GN,GT,GU080,090 30GN,GT,GU100,110 AND

AND MODULES 230B,245B/ MODULES 255B-315B
38AH094,104

Fig. 2 — Baffle Configuration for 09DK/30GN,GT,GU040-110 and Associated Modular Units

(See Table 1)/38AH044-134 Low-Ambient Operation

4
 LEGEND
TYP — Typical
NOTES:
1. Dimensions in ( ) are millimeters.
2. All units listed as modules consist of one module ‘‘A’’
plus one module ‘‘B.’’

Fig. 3 — ‘‘A’’ Baffle for Coil Section (09DK074-094/30GN,GT,GU060-090 and

Modules 230B,245B/38AH074-104 and Module 134B); ‘‘B’’ Baffle for Coil Section
(09DK094/30GN,GT,GU080,090 and Modules 230B,245B/38AH094,104)

LEGEND
TYP — Typical
NOTES:
1. Dimensions in ( ) are millimeters.
2. All units listed as modules consist of one module ‘‘A’’
plus one module ‘‘B.’’

Fig. 4 — ‘‘C’’ and ‘‘D’’ Baffles for Coil Section

(30GN,GT,GU100,110 and Modules 255B-315B)

5
 LEGEND
TYP — Typical
NOTES:
1. Dimensions in ( ) are millimeters.
2. All units listed as modules consist of one
module ‘‘A’’ plus one module ‘‘B.’’

Fig. 5 — ‘‘E’’ Baffles for Coil Section

(09DK074,084/30GN,GT,GU060,070/38AH074,084;
Module 134B)

LEGEND
TYP — Typical
NOTES:
1. Dimensions in ( ) are millimeters.
2. All units listed as modules consist of one
module ‘‘A’’ plus one module ‘‘B.’’

Fig. 6 — ‘‘F’’ Baffles for Coil Section

(09DK054,064/30GN,GT,GU040-050/38AH044-064;
Modules 124A/B, and 134A)

6
 09DK054,064/
30GN,GT,GU040-050/38AH044-064 AND
MODULES 124A/B,134A

09DK074-094/30GN,GT,GU060-110
AND MODULES 230B-315B/38AH074-104 AND
MODULE 134B
LEGEND
TYP — Typical
NOTES:
1. Dimensions in ( ) are millimeters.
2. All units listed as modules consist of one
module ‘‘A’’ plus one module ‘‘B.’’
Fig. 7 — Brackets for Coil Section (09DK/30GN,GT,GU040-110 and all
Associated Modular Units [See Table 1]/38AH044-134 Units)

7
 Summary of Baffles and Brackets
BAFFLE TYPE AND QUANTITY BRACKETS*
UNIT Length
30GN,GT,GU C D E QTY
in. mm
130-170,230A-270A 2 4 2 14 483⁄8 1229
190-210,290A,315A 4 8 — 16 483⁄8 1229
330A/B† 4 8 4 28 483⁄8 1229
360A/B (50 Hz)† 6 12 2 30 48 ⁄8
3 1229
360A/B (60 Hz)†, 390A/B†, 420A/B† 8 16 — 32 48 ⁄8
3 1229
*See Fig. 10 for bracket construction.
†Total unit (includes both modules).

BAFFLE SIZE
BAFFLE
in. mm
C 26 x 4511⁄16 660 x 1160
D 47 x 457⁄8 1194 x 1165
E 80 x 4511⁄16 2032 x 1160
NOTE: See Fig. 9 for baffle construction.

30GN,GT,GU130-170 AND MODULES 230A-270A, 330A/B

360B (50 Hz)

30GN,GT,GU190-210 AND MODULES 290A,315A,360A (50 AND 60 Hz),

360B (60 Hz), 390A/B,420A/B
Fig. 8 — Baffle Configuration for 30GN,GT,GU, Sizes 130-210,230A-315A,
330A/B-420A/B

8
 LEGEND
TYP — Typical
NOTE: Dimensions in ( ) are millimeters.
Fig. 9 — ‘‘C,’’ ‘‘D,’’ and ‘‘E’’ Baffles for 30GN,GT,GU130-210,230A-315A,
330A/B-420A/B

9
 LEGEND
TYP — Typical
NOTE: Dimensions in ( ) are millimeters.
Fig. 10 — Brackets for Coil Section — 30GN,GT,GU130-210,230A-315A,
330A/B-420A/B

Step 2 — Install MotormasterT III Controls —

Two Motormaster III controls must be added for each unit
(one control for each refrigerant circuit) with the following To avoid damaging components and wiring, use ex-
exceptions: treme care when drilling screw holes and screwing in
fasteners.
• 09DK054-094 units with 100% condenser coil circuiting
require only one control
• 30GN,GT,GU230-420 modular units require 4 controls SENSORS — Install sensor for thermistor input control in
(2 per modular unit) proper location on condenser coil. See Fig. 16-19. Connect
sensor leads to the violet and gray control signal leads on the
• 38AH024-034 units require only one control appropriate Motormaster III control. (Refer to Step 3 — Make
• 38AH044-084 units with factory-installed single circuit op- Electrical Connections on page 18 for wiring diagram
tion require only one control references for specific units).
• 38AH124,134 modular units require 2 controls (one per
modular unit) CONTROL SIGNAL SELECTION SWITCH — Remove
the cover of the Motormaster III control. Set switch on
See Fig. 11-15 for proper control mounting locations. Use Motormaster III control board (underneath cover) to accept
fasteners provided with controls to mount controls to parti- the thermistor sensor input signal. Also, set the frequency
tions. Drill required screw holes. selection switch to match unit power supply (50 Hz or
NOTE: Fan motors numbered in Fig. 11-15 are factory- 60 Hz). See Fig. 20 for switch locations and proper position.
installed motors that are compatible with the Motormaster III Replace the cover.
control.

10
 LEGEND
ATS — Air Temperature Switch
CR — Control Relay
DU — Dummy Terminal
EQUIP — Equipment
FC — Fan Contactor
FCPS — Fan Cycling Pressure Switch
FIOP — Factory-Installed Option
FM — Fan Motor
GND — Ground
MMSN — Motormaster Sensor
NEC — National Electrical Code
PL — Plug Assembly
TB — Terminal Block
TRAN — Transformer
XL — Across-The-Line Start
Terminal Block Connection
Marked Terminal
Unmarked Terminal
Unmarked Splice
Marked Wire
Factory Wiring
Field Wiring
Indicates Common Potential,
Does Not Represent Wiring
09DK054,064 09DK074-094
Fig. 11 — MotormasterT III Control Location; 09DK054-094 Units
(074-094 Units Shown)

11
 30GN,GT,GU040-050/38AH044-064;
MODULES 38AH124A/B,134A

30GN,GT,GU060,070/38AH074,084;
MODULE 38AH134B

NOTES:
1. For 38AH044-084 units with factory-installed single
circuiting, mount Motormaster control in position ‘‘A.’’
2. For 38AH124,134 modular units, mount Motormaster
control in position ‘‘A’’ in each module.

Fig. 12 — MotormasterT III Control Location;

30GN,GT,GU040-070/38AH044-084,124,134

30GN,GT,GU080,090; 30GN,GT,GU100,110;
MODULES 230B,245B/38AH094,104 MODULES 255B-315B

Fig. 13 — Motormaster III Control Location; 30GN,GT,GU080-110 and

Associated Modular Units (See Table 1)/38AH094,104

12
 Fig. 14 — MotormasterT III Control Locations
(30GN,GT,GU130-210; Modules 230A-315A and 330A/B-420A/B)

13
NOTE: Dimensions in ( ) are in millimeters.
Fig. 15 — MotormasterT III Control Location;
38AH024-034

14
NOTES:
1. Fan motor no. 1 Motormaster III control utilizes sensor 1.
2. Fan motor no. 2 Motormaster III control utilizes sensor 2.
3. For 09DK054-084 units with 100% condenser coil circuiting, mount sensor in position ‘‘1.’’
4. All views are from unit end opposite the control box.
5. For 09DK094, see Fig. 18.
Fig. 16 — MotormasterT III Sensor Locations
(09DK054-084)

15
 30GN,GT,GUT040,045/38AH044,054

30GN,GT,GU050/38AH064; MODULES 124A/B,134A

30GN,GT,GU060/38AH074; MODULE 134B

30GN,GT,GU070/38AH084
NOTES:
1. For 38AH044-084 units with factory-installed single circuiting, mount sensor in position ‘‘A.’’
2. For 38AH124,134 modular units, mount sensor in position ‘‘A.’’

Fig. 17 — MotormasterT III Sensor Locations

(30GN,GT,GU040-070/38AH044-084,124,134)

16
 09DK094/30GN,GT,GU080-110; MODULES 230B-315B/38AH094,104
NOTE: For 09DK094 unit with 100% condenser coil circuitry, mount sensor in position ‘‘A.’’

30GN,GT,GU130-210; MODULES 230A-315A,330A/B-420A/B

NOTE: Determine sensor location by viewing inside unit at 3-deck section, with compressors on left and
coolers on right.
Fig. 18 — MotormasterT III Sensor Locations
(09DK094/30GN,GT,GU080-420/38AH094,104)

HEADER END — 38AH024,028

HEADER END — 38AH034

Fig. 19 — Motormaster III Sensor Locations
(38AH024-034)

17
 LEGEND
GND — Ground *For thermistor (sensor) signal, move switch to the left.
NOTE: Thermistor is designated in text as ‘‘sensor.’’
Fig. 20 — MotormasterT III Control Signal Selection Switch

Step 3 — Make Electrical Connections NOTE: Check to be sure fan motor 1 is wired to
Motormaster III control A, and fan motor 2 is wired to
Motormaster III control B. For modular units, repeat this
installation in both modules.
To avoid possibility of electrical shock and personal in-
jury, turn off all power to unit before making electrical 30GN,GT,GU100,110 AND ASSOCIATED MODULAR
connections. Tag all disconnects to alert others not to UNITS (SEE TABLE 1)
turn power on until work is completed. 1. Connect the power wires to the control from the appro-
priate fan contactor, FC-A1 or FC-B1.
All the necessary wires required for wiring the 2. Remove the gray, orange, and blue wires from the ap-
Motormaster III control into the unit are in the wire harness propriate fan contactor.
for the unit.
3. Connect the gray fan motor wire to the red wire of the
09DK054,064/30GN,GT,GU040-050/38AH044-064 control.
1. Connect the power wires to the control from the appro- 4. Connect the orange fan motor wire to the brown wire of
priate fan contactor, FC-A1 or FC-B1 (FC1 or FC2 for the control.
09DK). 5. Connect the blue fan motor wire to the orange wire of the
2. Remove the red, brown, and orange wires from the fan control. See Fig. 25.
contactor. 6. Connect the green wire from the control to ground.
3. Connect the red fan motor wire to the red wire of the NOTE: Check to be sure fan motor 1 is wired to
control. Motormaster III control A, and fan motor 2 is wired to
4. Connect the brown fan motor wire to the brown wire of Motormaster III control B. For modular units, repeat this in-
the control. stallation in both modules.
5. Connect the orange fan motor wire to the orange wire of 30GN,GT,GU130-210 AND ASSOCIATED MODULAR
the control. See Fig. 21 (09DK) and 22 (30G/38AH). UNITS (SEE TABLE 1)
6. Connect the green wire from the control to ground. 1. Connect the power wires from Motormaster III control A
NOTE: Check to be sure fan motor 1 is wired to to FC-A1 and Motormaster III control B to FC-B1 as
Motormaster III control A, and fan motor 2 is wired to follows:
Motormaster III control B. a. Remove the red, brown, and orange wires from fan
motors 5 and 7 at FC-A1. Connect the red fan motor
09DK074-094/30GN,GT,GU060-090 AND ASSOCIATED wires to the red wire of control A, the brown fan mo-
MODULAR UNITS (SEE TABLE 1)/38AH074-104 tor wires to the brown wire of the control, and the
1. Connect the power wires to the control from the appro- orange fan motor wires to the orange wire of the con-
priate fan contactor, FC-A1 or FC-B1 (FC1 or FC2 for trol. See Fig. 26.
09DK). b. Remove the red, brown, and orange wires from fan
2. Remove the pink, violet, and gray wires from the appro- motors 6 and 8 at FC-B1. Connect the red fan motor
priate fan contactor. wires to the red wire of control B, the brown fan mo-
3. Connect the pink fan motor wire to the red wire of the tor wires to the brown wire of the control, and the
control. orange fan motor wires to the orange wire of the con-
4. Connect the violet fan motor wire to brown wire of the trol. See Fig. 26.
control. 2. Connect the green wire from the control to ground.
5. Connect the gray fan motor wire to the orange wire of the NOTE: For modular units, repeat this installation in both
control. See Fig. 23 (09DK) and Fig. 24 (30G/38AH). modules.
6. Connect the green wire from the control to ground.

18
38AH024-034 UNITS 3. Connect the red or pink fan motor wire to the red wire of
1. Cut the black, yellow, and blue wires that run out the back the control.
of the control box to outdoor fan motor no. 1 (FM1). Strip 4. Connect the brown or violet fan motor wire to the brown
the insulation back so that the wires can be connected wire of the control.
with field-supplied wire nuts to the power input wires on 5. Connect the orange or gray fan motor wire to the orange
the control. wire of the control.
2. Connect the black, yellow, and blue power wires from 6. Connect the green wire from the control to ground.
the back of the control box to the same color wires of the
control. ALL 575-V UNITS — If primary voltage is 575 v,
3. Connect the black wire from FM1 to the red wire of the 2 transformers (Carrier part no. HT01AH851) for each
control. Motormastert III control must be used to lower the supply
voltage to the control to 460 v. See Table 5 for ordering
4. Connect the yellow wire from FM1 to the brown wire of information and Fig. 29-36 for wiring.
the control.
On all units except 38AH024-034, transformers can be
5. Connect the blue wire from FM1 to the orange wire of mounted anywhere outside the control box.
the control. See Fig. 27.
On 38AH024-034 units, the transformers can be mounted
6. Connect the green wire from the control to ground. on a field-fabricated and supplied bracket at the end of the
09DK054-094 UNITS WITH 100% SINGLE CIRCUIT unit opposite the compressors. See Fig. 37. Mount the bracket
CONDENSER, 38AH044-084 UNITS WITH FACTORY- on the rail that supports the liquid and suction tubes (see
INSTALLED SINGLE CIRCUITING, AND MODULES Fig. 38). Cut a hole in the lower compressor compartment
124A/B,134A/B partition and use a 3⁄4-in. trade-size electrical connector to
run the wires into the compressor compartment (see Fig. 38
NOTE: For 124 and 134 units, instructions are per module. for hole location). Run the wires in conduit to comply with
1. Connect the power wires to the control from fan con- CSA (Canadian Standards Association) requirements.
tactor FC-A1 (FC1 for 09DK). On 09DK units, 4 access holes have been provided under
2. Remove the red, brown, and orange OR the pink, violet, the control box for incoming wiring. See Fig. 31.
and gray wires from the fan contactor. See Fig. 28.

LEGEND
FC — Fan Contactor
FM — Fan Motor
MMSN — Motormaster III Control Sensor
Fig. 21 — Fan Power Wiring — 09DK054,064
19
 LEGEND
FC — Fan Contactor
FCB — Fan Circuit Breaker
FM — Fan Motor
MMSN — MotormasterT III
Control Sensor
Fig. 22 — Fan Power Wiring — 30GN,GT,GU040-050/38AH044-064

LEGEND
FC — Fan Contactor
FM — Fan Motor
MMSN — Motormaster III
Control Sensor
Fig. 23 — Fan Power Wiring — 09DK074-094

20
 LEGEND
FC — Fan Contactor
FCB — Fan Circuit Breaker
FM — Fan Motor
MMSN — MotormasterT III
Control Sensor
Fig. 24 — Fan Power Wiring — 30GN,GT,GU060-090;
Modules 230B,245B/38AH074-104

LEGEND
FC — Fan Contactor
FCB — Fan Circuit Breaker
FM — Fan Motor
MMSN — Motormaster III
Control Sensor
Fig. 25 — Fan Power Wiring — 30GN,GT,GU100,110;
Modules 255B-315B

21
 LEGEND
FC — Fan Contactor
FCB — Fan Circuit Breaker
FM — Fan Motor
GND — Ground
MMSN — MotormasterT III Control
Sensor
Fig. 26 — Fan Power Wiring — 30GN,GT,GU130-210;
Modules 230A-315A, 330A/B-420A/B

LEGEND
CB — Circuit Breaker
FC — Fan Contactor
FM — Fan Motor
MMSN — Motormaster III Control Sensor
Fig. 27 — Fan Power Wiring — 38AH024-034
22
 LEGEND
FC — Fan Contactor
FM — Fan Motor
GND — Ground
MMSN — MotormasterT III Control Sensor
*RED, BRN, ORN — 38AH044-064, 38AH124A/B,
09DK054-064; PNK, VIO, GRA — 38AH074-
084, 38AH134A/B, 09DK074-094.

Fig. 28 — Fan Power Wiring — 09DK054-094 Units with 100% Condenser Coil Circuitry, 38AH044-084 Units
with Single-Circuit Option and Modules 38AH124A/B,134A/B

LEGEND
FC — Fan Contactor
FM — Fan Motor
MMSN — Motormaster III Control Sensor
TRAN — Transformer

Fig. 29 — 575-v Units, Autotransformer Circuit —

09DK054,064

23
 LEGEND
FC — Fan Contactor
FM — Fan Motor
MMSN — MotormasterT III Control
Sensor
TRAN — Transformer
Fig. 30 — 575-v Units, Autotransformer Circuit — 09DK074-094

LEGEND
ATS — Air Temperature Switch
Fig. 31 — 575-v Units, Power Wiring Access Holes — 09DK

24
 LEGEND
FC — Fan Contactor
FCB — Fan Circuit Breaker
FM — Fan Motor
MMSN — MotormasterT III
Control Sensor
Fig. 32 — 575-v Units, Autotransformer Circuit —
30GN,GT,GU040-050, 38AH044-064

LEGEND
FC — Fan Contactor
FCB — Fan Circuit Breaker
FM — Fan Motor
MMSN — Motormaster III
Control Sensor
TRAN — Transformer *And associated modular units.
Fig. 33 — 575-v Units, Autotransformer Circuit — 30GN,GT,GU060-110;
Modules 230B-315B; 38AH074-104

25
 LEGEND
FC — Fan Contactor
FCB — Fan Circuit Breaker
FM — Fan Motor
MMSN — MotormasterT III Control Sensor
TRAN — Transformer
Fig. 34 — 575-v Units, Autotransformer Circuit — 30GN,GT,GU130-210;
Modules 230A-315A, 330A/B-420A/B

26
 LEGEND
CB — Circuit Breaker
FC — Fan Contactor
FM — Fan Motor
MMSN — MotormasterT III
Control Sensor
TRAN — Transformer
Fig. 35 — 575-v Units, Autotransformer Circuit —
38AH024-034

LEGEND
FC — Fan Contactor
FM — Fan Motor
GND — Ground
MMSN — Motormaster III
Control Sensor
TRAN — Transformer
*RED, BRN, ORN — 38AH044-064, 38AH124A/B,
09DK054-064; PNK, VIO, GRA — 38AH074-
084, 38AH134A/B, 09DK074-094.
Fig. 36 — 575-v Units, Autotransformer Circuit — 09DK054-094 Units with 100% Condenser Coil Circuiting,
38AH044-084 Units with Single-Circuit Option and Modules 38AH124A/B, 134A/B

27
 14 GA. HOLES
mm (in.)
Symbol Diameter Number
Required
R 7.75/8.00 8
(.305/.315)
X 5.13/5.23 22
(.202/.206)

NOTE: Dimensions are in mm.

DIMENSIONS
mm in. mm in.
0.5 0.02 103.0 4.06
1.0 0.04 106.0 4.17
13.0 0.51 127.0 5.00
17.5 0.69 142.0 5.59
19.0 0.75 152.0 5.98
35.0 1.38 174.8 6.88
36.5 1.44 226.0 8.90
38.1 1.50 246.1 9.69
51.0 2.01 324.6 12.78
69.9 2.75 352.6 13.88
73.0 2.87 358.0 14.09
76.2 3.00 363.8 14.32
83.8 3.30 367.0 14.45
87.4 3.44 380.0 14.96
96.8 3.81 386.0 15.20
101.6 4.00 492.3 19.38

Fig. 37 — Field-Fabricated Transformer Mounting Bracket,

38AH024-034

28
NOTE: Dimensions are in inches. Dimensions in ( ) are in mm.
Fig. 38 — Recommended Transformer and Bracket Location,
38AH024-034

29
 START-UP 2. The power frequency switch must be in the correct po-
1. When all electrical connections are made, check that they sition for the power supply used and the control input
are correct and tight. switch must be turned toward the thermistor sensor
setting.
2. Check phase indicator light on Motormastert III control
after powering up the unit. The light should be out. If the 3. The only acceptable condenser-fan motors that can be used
light is lit, shut off power and reverse L1 (black) and L2 with Motormaster III control are Carrier part no.
(yellow) power leads. The motor will not operate when HD52AK346 and HD52AK652. If some other condenser-
the phase indicator light is lit. fan motor is installed, it must be changed to either an
HD52AK346 or an HD52AK652 motor. See Table 5.
3. With phasing to the Motormaster III control correct
(Step 2), check for correct rotation of the condenser fans 4. A true ‘‘root mean square’’ (RMS) meter is required
(clockwise). If fan rotation is backwards, shut off power, to accurately read the output from the Motormaster III
and reverse 2 of the supply power leads (red and orange) control because of the electronically controlled output
between the Motormaster III control and the condenser- voltage.
fan motors to correct fan rotation. 5. Thermistor sensor lead connections should be carefully
rechecked if there is an operational problem. The ther-
mistor characteristics shown in Table 7 apply to
TROUBLESHOOTING 30GT/GU412176. The control operates between 1600 ohms
The Motormaster III control is an electronic device. If a and 5800 ohms. At 1600 ohms, the control output is at
problem is discovered, check the following: full voltage and at 5800 ohms, the control output is at
1. The Motormaster III control device green ground wire minimum voltage or about 10% motor speed.
must be securely grounded to the cabinet of the unit to
function properly.

Table 7 — 30GT/GU412176 Thermistor Characteristics

TEMPERATURE RESISTANCE (OHMS)
°F °C Minimum Typical Maximum
60 15.5 7000 7750 8550
70 21.1 5300 5900 6500
77 25.0 4500 5000 5500
80 26.7 4175 4650 5100
90 32.2 3300 3650 4000
100 37.8 2600 2875 3180
110 43.3 2050 2275 2525
120 48.9 1650 1850 2050

30
Copyright 1998 Carrier Corporation

Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 1 2 2 PC 111 Catalog No. 533-087 Printed in U.S.A. Form 30GT-52SI Pg 32 11-98 Replaces: 30GT-40SI
Tab 3a 4a 5c