T6861-F Large LCD Digital Thermostat

230 VAC , Floating output

2-pipe fan coil control
Data sheet

Features
• Super modern appearance design, suitable for
office, hotel and residential building
• Horizontal and vertical model available for variant
application
• Slim design, direct installation on 86 size box
• Stylish and elegant blue/green backlight with white
• 2-pipe integrated into one unit with easy configuration
• Big LCD display with English and icons
• Easy to install and set-up
• Time on/off function
Application • Selectable room temperature or setpoint temperature
T6861-F digital thermostats are designed for display
application of 3-speed fan and floating valves in fan • Manual or automatic fan speed selection
coil system. • Remote sensor function
Including: • Adjustment of display room temperature
2-pipe cool only/heat only/manual changeover • Temperature unit either oC or oF
Ventilation mode • User setting can be kept when power off
Manual or automatic 3-speed fan control • Freezing protection function available
floating valve control • Lock or unlock keys or part of keys in Installer Set-up
• Heat and cool setpoint limitation for energy saving
Fan speed can be selected to automatic or manual
3-speed control mode.
In ventilation mode, fan only support manual speed
control.

Model summary
Horizontal/ Time 2-pipe/ Power supply Remote Manual/ Remote
Model Backlight Color Ring Ventilation
Vertical on/off 4-pipe (V) sensor Automatic Fan Setback

T6861H2WB-F Horizontal Blue White Y 2 230 Y Y Y N

T6861V2WB-F Vertical Blue White Y 2 230 Y Y Y N

T6861H2WG-F Horizontal Green White Y 2 230 Y Y Y N

T6861V2WG-F Vertical Green White Y 2 230 Y Y Y N

Note: Horizontal models are taken as samples for display, operation and installation pictures shown in below parts.

1
 Mechanical design Fan Operation

Thermostat appearnce
DIGITAL DISPLAY

FAN BUTTON
UP BUTTON

POWER BUTTON

MODE BUTTON DOWN BUTTON

PRESS THE FAN BUTTON TO SELECT

LOW, MED, HIGH OR AUTO

50030722-001 REV.A
Fan can be selected as manual or automatic 3-speed
operation. In Manual mode, the fan is switched to
LCD display the selected speed via control output Gh, Gm, Gl.
While in automatic mode, fan speed depends on the
difference between room temperature and setpoint.
When room temperature reaches setpoint, valve will
be closed and meanwhile, fan will be closed either.

100%
Fan speed is high
Open Degree of Valve

70%
Fan speed is medium
30%
Fan speed is low
0

Function
Fan speed ramping control algorithm
Floating Valve control
Thermostat acquires the room temperature via its
integrated sensor or external temperature sensor
and maintains the setpoint by delivering floating
valve control commands 3-position outputs. Temperature display
The displayed temperature can be set to acquired
room temperature or setpoint. The setting can be
made during Installer Set-Up process.

Time on/off
If the thermostat is off, hold power button for 3
seconds, system will be time on mode. If the
thermostat is on, hold power button for 3 seconds,
system will be time off mode.
The setting range is from 0 to 12 hours. The step is
PRESS THE MODE BUTTON TO SELECT
HEAT, COOL, AUTO OR VENT 0.5 hour with the default time is 0.

2
 Freezing protection mode
Freezing protection can be selected as disabled
(default) or enabled. In freezing protection mode
(no such mode in cool only application), when
thermostat is in OFF mode while the acquired
temperature is below 6oC, the thermostat will start
heat mode until the temperature rises to 8oC or the
thermostat is turned on.
INDICATES THERMOSTAT
HAS BEEN SET TIME OFF

Backlight
Any key press will activate the backlight. Backlights
will timeout 8 seconds after last key press. When
in Installer Set-up and Installer test mode, the
backlight will timeout 60 seconds after last key
press.

Keypad lock
Keypad lock can be set in ISU with default status
is all keys available. You may change into mode
button locked out, Fan and mode buttons locked out On/off mode
and All buttons locked out by changing the ISU. Pressing power button can switch between on and
off mode.

Operating modes
The following operating modes are available:

Comfort mode
In comfort mode, the setpoint can be changed by
pressing up and down button. Different applications
include cool only, heat only and manual heat/cool
changeover.

INDICATES THERMOSTAT
HAS BEEN SET TIME OFF
TEMPERATURE
SETTING
PRESS THIS BUTTON TO
RAISE THE TEMPERATURE
SETTING

Technical specification
Power supply 230 (+10%, -10%) VAC
Frequency 50Hz
Control algorithm PI, floating output
Accuracy +/-1oC at 21oC
Rating capacity For 230V power supply:
10(2)A for fan load, 3(1)A for valve
Ventilation mode Cycle times 100,000 times
Press mode button to enter ventilation mode. In Setpoint range 10~32oC
ventilation mode, no output for floating valve while Display range 0~37oC
the fan will operate according to selected fan speed. Installation Installed on 86×86mm
junction box or 3×3 inch.
Remote temperature sensor Protection Class IP20
T6861 provides control either depending on the Environmental Operation temperature -18~49oC
acquired room temperature or depends on the return Conditions Shipping temperature -35~65oC
air temperature. The model of remote temperature Relative humidity 5~90%,
sensor is (NTC20K). noncondensing

3
 Terminal Designations Application 3: 2 pipes 1 stage Heat or 1 stage Cool
MCO wiring diagram
Terminal Description

L Line voltage Power

Ch/Cc Valve close valve

W/Y Valve open

N Line voltage ground

Gl Low speed fan relay

Fan
Gm Medium speed fan relay

Gh High speed fan relay

remote sensor
Sc Ground for remote sensor

Rs Remote sensor
Figure 0-3 Typical wiring for 3-wire control in 2 pipes 1H1C

Wiring diagram Installation & Commissioning

Install the thermostat about 5 feet (1.5m) above the
Application 1: 2 pipes heat only wiring diagram floor in an area with good air circulation at average
temperature.

Heat valve

Fan

remote sensor

Do not install in locations where the thermostat can

Figure 0-1 Typical wiring for 3-wire control in 2 pipe heating only
be affected by:
• Drafts or dead spots behind doors and in corners
• Hot or cold air from ducts
• Sunlight or radiant heat from appliances
• Concealed pipes or chimneys
• Unheated/uncooled areas such as an outside wall
Application 2: 2 pipes Cool only wiring diagram

1 Pull wires through wire hole.

Cool valve Loosen screw terminals, insert wires into terminal
Block, then retighten screws.

Fan

remote sensor

Figure 0-2 Typical wiring for 3-wire control in 2 pipe cooling only

4
2 Push the Power box into the junction box. Installer system test
After completing the installer setup above, press the
button again to begin a system test
Follow the procedure below to test the heating and
cooling and fan system.

System test No.

System

3 Place Back cover over junction box, insert and

tighten mounting screws. Press and hold and buttons 3 seconds to enter
test mode.
Press or button to change system status.
Press button to advance to next test number.
Press and button hold to terminate system test
at any time.

System Test System Status

10 Valve open degree
0 Stop
1 Open
2 Close
40 Fan 0 Fan off
1 Low speed Fan on
4 Insert the cable into connector on circuit board of
2 Medium speed Fan on
thermostat.
3 High speed Fan on
70 Thermostat information (for reference only)
71 Software revision number (major revisions)
72 Software revision number (minor revisions)
73 Configuration identification code (major)
74 Configuration identification code (minor)
75 Production configuration date code (week)
76 Production configuration date code (year)

Installer Set-Up (ISU) setting

Press and simultaneously for 3 seconds to
enter ISU as below:
5 Align the 4 tabs on the Back cover with corresponding
slots on the back of the thermostat, and then push it
until the thermostat snaps in place.
Number

Setting

Press or to change settings

Press to advance to next function
Press and hold and buttons 3 seconds to
exit and save settings

5
 Setup Function Settings & Options Troubleshooting Tips
ISU Code Description Possible Options If… Then…
♦ Press
 Up and Down button and hold them about 3s.
0 Heat only ♦P ress Mode button to adjust the item to "10", and
Valve doesn't Press the Up button to modify the value to "2".
1 System Type 1 Cool only open ♦ Check the actuator. It must turn on slowly.
♦C heck the valve, if it still doesn't open, please call
2 Two pipes 1H1C manual (Default)
your supplier.
Floating Actuator 24 (120 seconds Default) The fan doesn’t ♦ Check whether the Fan mode is set to Auto
3
Running Time Range 6~32 (30~160 seconds) work. ♦ Check whether valve is open
The Mode
0 Onboard Sensor (Default) ♦ Check whether the keypad is locked or not.
button doesn’t
5 Remote Sensor
♦ Check whether the thermostat is off.
1 Remote sensor work.
(NTC20K, T7770A1006)
The Fan button ♦ Check whether the keypad is locked or not.
doesn’t work. ♦ Check whether the thermostat is off.
0 ºF
9 Temperature Scale The Up or Down
1 ºC (Default) ♦ Check whether the keypad is locked or not.
button doesn’t
♦ Check whether the thermostat is off.
work.
0 Auto Only

10 Fan Control Type 1 Constant Only

2 Both (Default)

-2 ºC (-4 ºF)
Dimension
-1.5 ºC (-3 ºF)

-1 ºC (-2 ºF)

-0.5 ºC (-1 ºF)

Display Temperature
18
Adjustment 0 ºC (0 ºF) (Default)

0.5 ºC (1 ºF)

1 ºC (2 ºF)

1.5 ºC (3 ºF)

2 ºC (4 ºF)
Horizontal model
0 Display Room Temperature
Temperature Display
19
Mode 1 Display Set point

2 Display Both (Default)

Heating Range 10-32 ºC Default 32 ºC

20
Stops (50-90 ºF Default 90 ºF)

Cooling Range 10-32 ºC Default 10 ºC

21
Stops (50-90 ºF Default 50 ºF)

0 All keys are available (Default)

1 System button is Locked out

22 Keypad Lockout
2 Fan and System button are Locked out

3 All buttons are locked out

0 Disabled
27 Freeze Protection
1 Enabled
Vertical model