Honeywell 63 2666 03 Thermostat User Manual

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T7351 Commercial Programmable Thermostat  
FOR SINGLE- OR MULTI-STAGE CONVENTIONAL/HEAT PUMP SYSTEMS  
PRODUCT DATA  
FEATURES  
Typically used in buildings (including: restaurants,  
shopping malls, office buildings and banks) under  
55,000 square feet.  
For single zone rooftop units, split systems, heat  
pumps or hot/chilled water systems.  
365-day programming.  
Two Occupied and two Not Occupied periods per day.  
Individual heat and cool setpoints available for  
Occupied and Not Occupied periods.  
P+I+D control minimizes temperature fluctuations.  
Recovery ramp control automatically optimizes  
equipment start times based on building load.  
Convenient overrides allow temporary setpoint  
changes.  
APPLICATION  
The T7351 Commercial Programmable Thermostat controls  
Keypad multi-level lockout available with all models.  
Remote sensor capability for temperature (including  
outdoor air and discharge air) and humidity sensors.  
2
4 Vac commercial single zone heating, ventilating and air  
conditioning (HVAC) equipment. The T7351 consists of a  
thermostat and subbase. The thermostat includes the keypad  
and display for 365-day programming. The subbase includes  
equipment control connections. The subbase mounts on the  
wall and the thermostat mounts to the subbase.  
Auxiliary subbase contact typically interface with a  
Honeywell Economizer System (for total rooftop  
control integration) or act as dehumidification output.  
Universal Versaguard Thermostat guards available.  
Contents  
Application ........................................................................  
Features ...........................................................................  
Specifications ...................................................................  
Ordering Information ........................................................  
Setting ..............................................................................  
Installer Setup ..................................................................  
1
1
2
2
6
7
Operation .......................................................................... 12  
Troubleshooting Guide (Table 11) ..................................... 17  
Wiring Diagram (Figures 14 and 15) ................................ 19  
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T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
SPECIFICATIONS  
IMPORTANT  
Models: See Table 1.  
The specifications given in this publication do not  
include normal manufacturing tolerances. Therefore,  
this unit might not exactly match listed specifications.  
This product is tested and calibrated under closely  
controlled conditions; minor performance differ-  
ences can be expected if those conditions are  
changed.  
Dimensions: Refer to Fig. 1.  
Finish (color): Trident White.  
Batteries: No batteries required  
Table 1. T7351 Thermostat Features  
Maximum Stagesa  
Heat Cool  
Auxiliary  
Relay  
Model  
T7351F  
Application  
Features  
Conventional or  
Heat Pump  
(2)b  
3 (4)b  
Humidity, Occupancy,  
Outdoor, Discharge Air Capability  
Yes  
3
a
b
This model is down-selectable and can be configured to control fewer stages than the maximum allowed.  
Heat pump applications for this model have a maximum of two heat stages and two cool stages.  
Mounting Means:  
Outdoor Sensor Wiring: Requires 18 gauge wire.  
Humidity Ratings: 5% to 90% RH, noncondensing.  
Mounts on subbase.  
Subbase Mounts On:  
Wall: Using two 5/8 in. long #6-32 screws (included).  
Outlet Box: Using sheet metal screws.  
Emergency Heat Indication:  
Display indicates when Emergency Heat is activated (Em).  
Clock Accuracy at 77° F (25° C): ±1 min./month (30 days).  
Temperature:  
Ratings:  
Minimum Stage Operation Time (fixed):  
Minimum On  
Heat: 1 minutes.  
Cool: 3 minutes.  
Minimum Off (Cool and Heat Pump): 1 minute.  
Operating Ambient: 30° to 110° F (-1° to 43° C).  
Shipping: -30° to +150° F (-34° to +66° C).  
Display Accuracy: ±1° F (±1° C).  
Setpoint:  
Range:  
Electrical Ratings:  
Power: 24 Vac, 50/60 Hz.; 20 to 30 Vac, 50/60 Hz.  
Input:  
Heating: 40° to 90° F (4° to 32° C).  
Cooling: 45° to 99° F (7° to 37° C).  
Deadband: 2° F (1° C).  
Temperature: 20K ohms.  
Default Settings: Refer to Table 2.  
Humidity: 0-10 Vdc.  
Outdoor: 3000 PTC.  
Discharge Air: 20K ohms.  
Occupancy Sensor: Dry contact switching 30 Vdc at 1 mA.  
All Relay Outputs (at 30 Vac):  
Running: 1.5A maximum.  
Loss of Power: The thermostat maintains programmed times  
and temperatures for the life of the product. Clock and day  
information is retained for a minimum of 48 hours.  
NOTE: To achieve the 48-hour power-loss clock reten-  
tion, the T7351 must be powered for at least 5  
minutes.  
Inrush: 7.5A maximum.  
System Current Draw (without load):  
5
VA maximum at 30 Vac, 50/60 Hz.  
Approvals:  
UL 873 Recognized, NEC Class 2.  
FCC Part 15 subpart J Class A.  
cUL.  
NOTE: Relays are N.O. Single-Pole, Single-Throw  
(
SPST).  
ORDERING INFORMATION  
When purchasing replacement and modernization products from your TRADELINE® wholesaler or distributor, refer to the  
TRADELINE® Catalog or price sheets for complete ordering number. If you have additional questions, need further information,  
or would like to comment on our products or services, please write or phone:  
1
.
.
Your local Honeywell Environmental and Combustion Controls Sales Office (check white pages of your phone directory).  
Honeywell Customer Care  
2
1885 Douglas Drive North  
Minneapolis, Minnesota 55422-4386  
http://customer.honeywell.com or http://customer.honeywell.ca  
3.  
International Sales and Service Offices in all principal cities of the world. Manufacturing in Belgium, Canada, China, Czech  
Republic, Germany, Hungary, Italy, Mexico, Netherlands, United Kingdom, and United States.  
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T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
Table 2. Default Setpoints.  
Occupied Not Occupied  
INSTALLATION  
Control  
Heating  
Cooling  
Standby  
70° F (21° C) 55° F (13° C) 67° F (19° C)  
75° F (24° C) 85° F (29° C) 78° F (26° C)  
When Installing this Product...  
1.  
Read these instructions carefully. Failure to follow them  
could damage the product or cause a hazardous  
condition.  
2
-3/16 (56)  
1
(
-9/16  
40)  
2. Check ratings given in instructions and on the product to  
6
-3/4 (171)  
ensure the product is suitable for your application.  
3
.
.
Installer must be a trained, experienced service  
technician.  
After installation is complete, check out product  
operation as provided in these instructions.  
4
4
-1/2  
114)  
(
CAUTION  
Electrical Shock or Equipment Damage Hazard.  
Can shock individuals or short equipment circuitry.  
Disconnect power supply before installation.  
SUBBASE  
IMPORTANT  
All wiring must agree with applicable codes,  
2
(
-1/32  
52)  
ordinances and regulations.  
4
(
-1/16  
104)  
2
(
-1/32  
52)  
MERCURY NOTICE  
If this control is replacing a control that contains  
mercury in a sealed tube, do not place your old control  
in the trash. Dispose of properly.  
1
(
-5/8  
42)  
2-3/8 (60)  
-1/4 (83)  
-9/16 (166)  
1-5/8  
(42)  
3
M22432  
6
Contact your local waste management authority for  
instructions regarding recycling and the proper disposal  
of an old control. If you have questions, call Honeywell  
Customer Care Center at 1-800-468-1502.  
Fig. 1. Thermostat and Subbase Dimensions  
in inches (mm).  
Accessories:  
Duct Discharge Air Sensors:  
Location  
Do not install the thermostat where it can be affected by:  
C7041B (6 or 12 in. [152 or 305 mm]),  
C7041C (18 in. [457 mm]),  
C7041J (12 ft. [3.66 m] averaging),  
C7770A (8 in. [203 mm] probe).  
drafts, or dead spots behind doors and in corners.  
hot or cold air from ducts.  
radiant heat from sun or appliances.  
concealed pipes and chimneys.  
unheated (uncooled) areas such as an outside wall behind  
the thermostat.  
Outdoor Air Sensors: C7170A,  
C7031G2014 (weatherproof).  
Temperature Sensors (Remote): C7772A, TR21, TR22, TR23,  
and TR24 series, TR21-WK, TR23-WK, T7771.  
Economizer Logic Modules: W7210, W7212, W7215, W7459.  
Humidity Sensors: H7625, H7635.  
Others:  
Subbase  
WHEN USED TO SENSE ROOM TEMPERATURE  
Install the thermostat about 5 ft. (1.5 m) above the floor in an  
area with good air circulation at average temperature. (Refer to  
Fig. 3.)  
2
09541B FTT network termination module.  
209651A Vertical Mounting Hardware Wallplate Adapter  
(
Trident white).  
5
0000452-001 Troubleshooting Cable.  
TG512 Universal Versaguard Thermostat guards.  
WHEN NOT USED TO SENSE ROOM TEMPERATURE  
When using the remote-mounted temperature (and humidity)  
sensor(s) to sense ambient conditions, install the thermostat in  
an area that is accessible for setting and adjusting the  
temperature and settings.  
3
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T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
Wall mounting (using standard drywall screws) is standard.  
Mounting to a 2 in.(50.8 mm) by 4 in. (101.6 mm) wiring box  
can be accomplished:  
CAUTION  
Equipment Damage Hazard.  
for a horizontal box, no extra hardware is required.  
for a vertical box, part 209651A is required.  
Mount to European standard wall box 2.4 in. (having 61 mm  
between mounting screws in a horizontal line) with or  
without adaptive hardware.  
Can damage the TIM connection beyond repair.  
Disconnect the TIM cable prior to opening or closing  
the thermostat cover.  
NOTE: Allow sufficient clearance below the thermostat to  
plug in the TIM cable.  
1.  
Position and level the subbase.  
NOTE: A level wallplate is only for appearance. The  
thermostat functions properly when not level.  
Install the remote-mounted sensor(s) about 5 ft. (1.5 m) above  
the floor in an area with good air circulation at average  
temperature. (See Fig. 2.)  
2
.
.
Use a pencil to mark the mounting holes.  
(
Refer to Fig. 6.)  
Remove the subbase from the wall and drill two 3/16 in.  
4.76 mm) holes in the wall (if drywall) as marked. For  
firmer material such as plaster or wood, drill two 7/32 in.  
5.56 mm) holes.  
NOTE: Only TR21 models with neither setpoint adjust-  
ment nor bypass can be used for temperature  
averaging.  
3
(
(
4
.
.
Gently tap anchors (provided) into the drilled holes until  
flush with the wall.  
Position the subbase over the holes, pulling wires  
through the wiring opening.  
5
YES  
NO  
6
.
.
Loosely insert the mounting screws into the holes.  
Tighten mounting screws.  
7
NO  
NO  
5 FEET  
1.5 METERS)  
(
SUBBASE  
T4  
T3  
TR21  
T
TR21  
T
T
T
M4823A  
Fig. 2. Typical Location of Thermostat or Remote-Mounted  
Sensor.  
TR21  
T
TR21  
T
IMPORTANT  
T
T
To avoid electrical interference, which can cause  
erratic performances, keep wiring runs as short as  
possible and do not run thermostat wires adjacent to  
the line voltage electrical distribution systems. Use  
shielded cable (Belden type 8762 or equivalent for  
M29184  
2-wire). The cable shield must be grounded only at  
the controlled equipment case.  
Fig. 3. Four TR21 Sensors providing a Temperature  
Averaging Network for T7351 Thermostat.  
Mounting Subbase  
The subbase mounts horizontally or vertically.  
T7350 SUBBASE  
T4  
T3  
IMPORTANT  
When using the internal temperature sensor, the  
device must be mounted horizontally (with the LCD  
facing upwards). Precise leveling is not needed.  
When using remote sensors, thermostat mounting  
orientation does not matter.  
T4  
T3  
T4  
T3  
1
1
TR21-A  
TR21-A  
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T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
SUBBASE  
Wiring  
T4  
T3  
TR21  
T
TR21  
T
TR21  
T
CAUTION  
T
T
T
T
T
Electrical Shock or Equipment Damage Hazard.  
Can shock individuals or short equipment circuitry.  
Disconnect power supply before installation.  
IMPORTANT  
TR21  
T
TR21  
T
TR21  
T
All wiring must comply with local electrical codes and  
ordinances.  
T
T
NOTE: Maximum (and recommended) wire size is 18-  
gauge (ø 1.02 mm). Do not use wire smaller than  
22-gauge (ø 0.644 mm).  
TR21  
T
TR21  
T
TR21  
T
Follow equipment manufacturer wiring instructions when  
available. Refer to the Wiring Diagram section for typical  
hookups. A letter code is located near each terminal for  
identification. Refer to Tables 3 for terminal designations.  
T
T
1.  
Loosen subbase terminal screws and connect system  
wires.  
M29257  
2.  
3.  
4.  
Securely tighten each terminal screw.  
Push excess wire back into the hole in the wall.  
Plug the hole with nonflammable insulation to prevent  
drafts from affecting the thermostat.  
Fig. 5. Nine TR21 Sensors Providing a Temperature  
Averaging Network for T7351 Thermostat.  
WIRES THROUGH WALL  
MOUNTING  
HOLES  
WALL  
ANCHORS  
(
2)  
MOUNTING  
SCREWS  
M19608  
Fig. 6. Mounting the Subbase.  
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3.  
Press the lower edge of the case to latch.  
Table 3. T7351 Subbase for Three-stage Heat, Three-stage  
Cool Systems.  
NOTE: To remove the thermostat from the wall, first pull  
out at the bottom of the thermostat; then  
remove the top.  
Terminal  
A. ENGAGE TABS AT TOP OF THERMOSTAT AND SUBBASE OR WALLPLATE.  
Description  
RCa RC  
a 24 VAC Cooling transformer.  
a 24 VAC Heating transformer.  
X Common.  
RHa RH  
X
aux aux Auxiliary relay.  
W1 O/B Conventional: Stage 1 heating relay.  
Heat Pump: Changeover relay for heating (B) or  
b
cooling (O) .  
W2 W1 Conventional: Stage 2 heating relay.  
Heat Pump: 1st Stage auxiliary heat relay.  
Y1  
Y1 Conventional: Stage 1 cooling relay.  
Heat Pump: Stage 1 compressor relay.  
Y2  
Y2 Conventional: Stage 2 cooling relay.  
Heat Pump: Stage 2 compressor relay.  
B. PRESS LOWER EDGE OF CASE TO LATCH.  
AS AS Discharge Air Sensor connection (1).  
AS AS Discharge Air Sensor connection (2).  
OS OS Outdoor Air Sensor connection (1).  
OS OS Outdoor Air Sensor connection (2).  
G
G
Fan relay.  
T3  
T4  
T5  
T6  
T7  
T3 TR20 Series Remote Sensor connection (1).  
T4 TR20 Series Remote Sensor connection (2).  
T5 TR20 Series Remote Sensor connection (5).  
T6 TR20 Series Remote Sensor connection (9).  
T7 TR20 Series Remote Sensor connection (7).  
W3 W2 Conventional: Stage 3 heat or stage 4 cool relay.  
Heat Pump: 2nd Stage auxiliary heat relay.  
M19609  
Y3  
Conventional: Stage 3 cooling relay.  
HS HS Humidity Sensor connection (signal: 0-10 Vdc).  
TR23-H connection (11)  
Fig. 7. Mounting Thermostat on Subbase.  
HC HC  
Humidity Sensor connection (common).c  
SETTING  
HP HP Humidity Sensor connection (power). TR23-H  
connection (12)  
Using Thermostat Keys  
M
M
M
M
Motion Sensor connection (1).  
Motion Sensor connection (2).  
The thermostat keys are used to:  
set current time and day,  
a
Factory jumper between RC and RH for systems with one  
transformer.  
program times and setpoints for heating and cooling,  
override the program temperatures,  
display present setting,  
set system and fan operation,  
perform simple configuration.  
b
c
For changeover functional details, see Operation section.  
HC connection is not needed when using a TR23-H sensor.  
Mounting Thermostat on Subbase  
Fig. 7)  
NOTE: Refer to Fig. 8 for keypad information.  
(
Setting Temperature  
Refer to Table 2 for the default temperature setpoints. See  
Programming section for complete instructions on changing  
the setpoints.  
With the subbase installed, mount the thermostat:  
1.  
Engage the tabs at the top of the thermostat and sub-  
base.  
2.  
Swing the thermostat down.  
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T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
Setting System and Fan  
System default setting is Auto. Fan default setting is On.  
Fan Settings.  
On: See Table 4.  
Auto: Fan always cycles with call for heating or cooling.  
NOTE: Use System and Fan keys to change settings.  
Conventional: The equipment (i.e. plenum switch)  
controls fan operation in heat mode. The thermostat  
controls fan operation in cool mode.  
Electric Heat: The thermostat controls fan operation in  
both heat and cool modes.  
System Settings  
Auto: Thermostat automatically changes between heating  
and cooling based on indoor temperature.  
Cool: Thermostat controls only cooling.  
Off: Heating, cooling, and fan are all off.  
Heat: Thermostat controls only heating.  
Em Heat: Auxiliary heat serves as first stage. Compressor  
stages are locked off.  
NOTE: Fan operation can extend (delay Off) after the  
heating/cooling turns off:  
Heating choices are 0 or 90 seconds.  
Cooling choices are 0 or 40 seconds.  
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Table 4. T7351 Intelligent™ Fan ON control logic  
Call for  
Heat/Cool  
Occupancy  
Scheduled  
Period  
Motion Sensor  
Signal  
Effective  
Occupancy  
Yes  
No  
Notes  
Occupied  
Occupied  
No Sensor Wired  
Motion Sensed  
Occupied  
Occupied  
Fan On Fan On  
Fan On Fan On  
Effective Occupancy is Standby. Standby  
setpoints are used and it assumes that the  
space is unoccupied. Fan is on only when there  
is a call for heating or cooling.  
Occupied  
No Motion Sensed  
Standby  
Fan On Fan Offa  
Not Occupied No Sensor Wired Not Occupied Fan On Fan Offa  
Not Occupied Motion Sensed Not Occupied Fan On Fan Offa  
Not Occupied No Motion Sensed Not Occupied Fan On Fan Off  
Occupancy sensor will only be active during  
scheduled Occupied periods. During scheduled  
Not Occupied periods, the effective occupancy  
a will always be Not Occupied.  
a
In heat mode, when set for conventional heat, the equipment (i.e. plenum switch) could power the fan despite the T7350.  
Temperature  
Not Occupied  
Set Day/Time  
Override  
Temporary Temporary  
Occupied Not Occupied  
Occupied  
Day  
Time  
HEAT  
COOL  
HEAT  
COOL  
Schedule  
System  
Fan  
Run  
Clear  
Day  
Occupied Not Occupied Start Time  
Copy  
HEAT COOL  
ON AUTO  
Schedule  
M19610  
Fig. 8. Thermostat Key Locations.  
INSTALLER SETUP  
For most applications, the thermostat factory settings do not  
need to be charged. Review the factory settings in Table 2.  
Setup Using Keypad  
The installer uses the Installer Setup to customize the  
thermostat to specific systems.  
NOTE: When power is first applied to the thermostat, the  
display will show all segments (See Fig. 9).  
A combination of key presses are required to use the Installer  
Setup features.  
TemporaryStandby Set Set Schedule Room  
Not Occupied12 StartTime  
AM  
PM  
1. To enter the Installer Setup, press and hold both the Run  
Schedule and the Copy keys until DEGREES 00 (or  
DEGREES 01) displays.  
%
MonTueWedThuFriSatSunHol MinsDays  
Fan  
OnAuto  
System  
EmHeat  
OffCoolAuto Dehumid  
NOTE: Installer Setup will display WAIT and is  
unavailable for 30 seconds after power up.  
M19611  
Fig. 9. LCD Display of all Segments.  
2.  
To advance to the next Installer Setup number, press  
.
NOTE: Pressing Run/Copy again while in this mode  
CAUTION  
displays the T7351 firmware version number.  
Possible Equipment Damage.  
Fan must be running when system is operating.  
Heat pump and electric heat systems must be  
configured correctly to prevent equipment damage  
caused by the system running without the fan.  
3. To return to a Setup item, cycle through the options.  
4. To change a setting, use the up  or down  key.  
5. To exit the Installer Setup, press Run Schedule.  
6. Display prompts SAV CFG (save configuration).  
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T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
a. If you want to save the new configuration, use the up  
NOTE: Installer Setup is automatically exited after five  
minutes with no key pressed. Upon this automatic  
exit, all changes are lost.  
or down key to change NO to YES before  
pressing Run Schedule.  
b. If you want the configuration to remain as it was  
before starting this change, ensure the  
display indicates SAV CFG NO and press Run  
Schedule.  
Configuration  
Configuration can be done with the keypad using the Installer Setup (ISU).  
Table 5. Installer Setup.  
Text  
Default  
Choices  
0 -1  
Notes  
DEGREES 0  
Degree Temperature Format  
0
1
: Degrees F  
: Degrees C  
CLOCK  
0
0
0 - 1  
0 - 3  
Clock Display Format  
0
1
: 12 hour  
: 24 hour  
KEYLOCK  
Keypad Lockout Level  
0
1
: None  
: Lockout all keys except Set Day, Set Time, Set Date, Set Holidays, Temporary  
Occupied, Temporary Not Occupied, System, Fan, Up, Down and Information  
: Lockout all keys except Set Day, Set Time. Set Date, Set Holidays, Temporary  
Occupied, Temporary Not Occupied, Up, Down and Information  
: Lockout all keys except Information  
2
3
HEATPMP  
0
0 - 2  
0 - 4  
Application Type Selection  
0
1
2
: Conventional  
: Heat Pump - Cooling (Energize O/B on call for cool)  
: Heat Pump - Heating (Energize O/B on call for heat)  
COOLSTG 1  
Number of Cooling Stages  
0
1
2
3
4
: 0 Stages of Cooling  
: 1 Stages of Cooling  
: 2 Stages of Cooling  
: 3 Stages of Cooling (Not available if Heat Pump is selected)  
: 4 Stages of Cooling (W3 will be used as 4th stage relay) (Not available if Heat Pump is  
selected)  
HEATSTG  
1
0 - 3  
Number of Conventional Heating Stages (Not available if Heat Pump is selected)  
0
1
2
3
: 0 Stages of Heating  
: 1 Stages of Heating  
: 2 Stages of Heating (This is the max if 4 cooling stages is selected)  
: 3 Stages of Heating  
AUX STG  
AUX CON  
0
0
0 - 2  
0 - 3  
Number of Heat Pump Heating Stages (Only shown when Heat Pump is selected)  
0: 0 Aux Stages  
1: 1 Aux Stages  
2: 2 Aux Stages  
Aux Contact Functionality  
0
1
2
3
: Time of Day  
: Economizer  
: Dehumid - Hot Gas Bypass  
: Simple Dehumid  
WALLMOD 0  
0 - 3  
Remote Room Sensor Selection  
0
1
2
3
: Local sensor only  
: TR21/TR24 and T7770A/D (Remote Sensor, No Remote Setpoint, Bypass 0)  
: TR22/TR23 and T7770B/C (Remote Sensor, Remote Setpoint, Bypass 0)  
: T7771 (Remote sensor, Remote Setpoint, Bypass 1)  
(
Bypass 0 means that by pressing the override button the thermostat goes from  
unoccupied to occupied and the LED will light up and the temporary occupied timer will  
begin. If the button is pressed again, the timer will restart.)  
(
Bypass 1 means that by pressing the override button a second time the thermostat can  
return to the unoccupied period.)  
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Table 5. Installer Setup. (Continued)  
Notes  
Text  
Default  
Choices  
0 - 1  
OATSENS  
0
Outdoor Air Sensor Selection  
0
1
: None  
: Remote Outdoor Air Sensor  
DATSENS  
0
0 - 1  
0 - 2  
Discharge Air Sensor Selection  
0
: None  
1: Remote Discharge Air Sensor  
HUMSENS 0  
OCCSENS 0  
Room Humidity Sensor selection  
0
1
2
: None  
: On Board Sensor  
: Remote Sensor  
0 - 1  
Occupancy Sensor Selection  
0
: None  
1: Remote Occ Sensor  
FAN HT  
0
0 - 1  
Fan Operation on Heat  
0: Conventional (Equipment controls Fan)  
1: Electric (Thermostat turns on Fan with call for Heat)  
XFAN HT YES  
XFAN CL NO  
YES or NO  
YES or NO  
Extended Fan on Heat  
NO: None  
YES: 90 seconds  
Extended Fan on Cool  
NO: None  
YES: 40 seconds  
STRTDEL  
0
0 - 15  
Sequential Start Delay  
0
to 150 seconds in 10 second increments  
ADVANCE NO  
YES or NO  
Advanced Settings  
NO: Hide  
YES: Show  
TMP LIM  
3
0 - 5  
Temporary Setpoint Adjustment  
0: 0 Deg. F  
1: 1 Deg. F  
2: 2 Deg. F  
3: 3 Deg. F  
4: 4 Deg. F  
5: 5 Deg. F  
TMP OCC  
TMP CAL  
3
0
1 - 8  
Temporary Occupied Duration  
to 8 hours  
1
-4 - 3  
Temporary Display Adjustment  
0
4
- 3 = 0 to 3 DDF  
- 7 = -4 to -1 DDF  
MINCOOL 45° F  
7° C)  
45° - 99° F  
(7° - 37° C)  
Min Cool Setpoint  
(
MAXHEAT 90° F  
40° - 90° F  
Max Heat Setpoint  
(
32° C) (4° - 32° C)  
HEATLCK NO  
YES or NO  
Heating Lockout (Only displayed if Outdoor Air Sensor is selected)  
NO: None  
YES: Enabled  
HTLCKSP 70° F  
-40° - 120 ° F Heating Lockout Temperature  
(
21° C) (-40° - 49° C) (Display only if Remote Outdoor Air Sensor is configured)  
COOLLCK NO  
YES or NO  
Cooling Lockout (Only displayed if Outdoor Air Sensor is Selected)  
NO: None  
YES: Enabled  
CLLCKSP 35° F  
-40° - 120° F  
(-40° - 49° C)  
Cooling Lockout Temperature  
(Display only if Remote Outdoor Air Sensor is configured)  
(
2° C)  
DAT LL  
NO  
YES or NO  
Discharge Low Limit (Only displayed if Discharge Air Sensor is Selected)  
NO: None  
YES: Enabled  
DATLLSP 45° F  
7° C)  
35° - 60° F  
(2° - 16° C)  
Discharge Low Temp Limit  
(Display only if Discharge Sensor is configured)  
(
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Table 5. Installer Setup. (Continued)  
Text  
Default  
Choices  
Notes  
DAT HL  
NO  
YES or NO  
Discharge High Limit (Only displayed if Discharge Air Sensor is Selected)  
NO: None  
YES: Enabled  
DATHLSP 110° F 65° - 140° F  
43° C) (18° - 60° C)  
Discharge High Temperature Limit  
(Display only if Discharge Sensor is configured)  
(
DEHUMID  
0
0 - 5  
Dehumidification  
0
1
2
3
4
5
: None  
: MinOn Time  
: Reset Temp Setpoint  
: Reset w/ MinOn  
: Reheat  
: Reheat w/ Min On  
DEH MIN  
DEH TMP  
MINHTRT  
5
2
5
5 - 15  
1 - 5  
Dehumidify Minutes On  
Dehumidify Temp Reset  
0 - 20 DDF/HR Minimum Heat Recovery Ramp Rate  
MAXHTRT 8  
0 - 20 DDF/HR Maximum Heat Recovery Ramp Rate (Only Displayed if Outdoor Sensor is Selected)  
MINHTOA 0° F  
-20° - 120° F  
Minimum Heat Outdoor Air Temperature (Only Displayed if Outdoor Sensor is Selected)  
(
-18° C) (-29° - 49° C)  
MAXHTOA 40° F  
4° C)  
-20° - 120° F  
(-29° - 49° C)  
Maximum Heat Outdoor Air Temperature (Only Displayed if Outdoor Sensor is Selected)  
(
MINCLRT  
3
0 - 20 DDF/HR Minimum Cool Recovery Ramp Rate  
MAXCLRT 6  
0 - 20 DDF/HR Maximum Cool Recovery Ramp Rate (Only Displayed if Outdoor Sensor is Selected)  
MINCLOA 90° F  
-20° - 120° F  
Minimum Cool Outdoor Air Temperature (Only Displayed if Outdoor Sensor is Selected)  
(32° C) (-29° - 49° C)  
MAXCLOA 70° F -20° - 120° F  
Maximum Cool Outdoor Air Temperature (Only Displayed if Outdoor Sensor is Selected)  
(21° C) (-29° - 49° C)  
(DayLight Savings options only display when Date is valid)  
DSTMON1 3  
0 - 12  
DLS Spring Month  
DSTDAY1 40  
0 - 31, 32 - 74 DLS Spring Day  
0 - 31 = Day of Month  
32 = Last Day of Month  
33 = First Sunday  
etc…  
DSTMON2 11  
DSTDAY2 33  
0 - 12  
DLS Fall Month  
0 - 31, 32 - 74 DLS Fall Day  
0
3
3
- 31 = Day of Month  
2 = Last Day of Month  
3 = First Sunday  
etc…  
HT RESP  
CL RESP  
1
0
0 - 3  
0 - 1  
0: Standard - 3 cph  
1
2
3
: Medium - 6 cph  
: Fast - 9 cph  
: Super Fast - 20 cph  
0: Standard - 3 cph  
: Fast - 4 cph  
1
4.  
Use the Up/Down keys to set the day, then press the  
key (Refer to Table 4 for valid day choices).  
Holidays and 365 - Day Clock  
The T7351can be configured to schedule up to 10 separate  
holidays, each with a duration of up to 99 days. To enable this  
function, the user must set the date:  
5. Use the Up/Down keys to set the year, then press the  
key.  
Holidays can be set in the following manner:  
1.  
2.  
3.  
Press the “Temporary Occupied” and Temporary Not  
Occupied” keys simultaneously.  
The month (MON) of the first holiday is then displayed  
1
.
.
Press Set Day and Set Time keys simultaneously.  
Use the Up/Down keys to set the date to YES, then press  
2
the  
key.  
(
00 means the holiday is ignored).  
3.  
Use the Up/Down keys to set the month, then press the  
key.  
Use the Up/Down keys to set the month, then press the  
key.  
11  
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4
.
.
Use the Up/Down keys to set the day, then press the  
key (Refer to Table 6 for valid day choices).  
Use the Up/Down keys to set the duration.  
The first holiday is now set and pressing the  
key will take  
you to programming the second holiday (denoted by the  
number 2 on the screen)  
5
Table 6. Valid Day Values.  
Value Description  
Value  
Description  
1
to 31 Day of month  
42  
43  
44  
45  
46  
47  
48  
49  
50  
51  
52  
Second Tuesday  
Second Wednesday  
Second Thursday  
Second Friday  
Second Saturday  
Third Sunday  
53 Third Saturday  
54 Fourth Sunday  
55 Fourth Monday  
56 Fourth Tuesday  
57 Fourth Wednesday  
58 Fourth Thursday  
59 Fourth Friday  
60 Fourth Saturday  
61 Fifth Sunday  
64  
65  
66  
67  
68  
69  
70  
71  
72  
73  
74  
Fifth Wednesday  
Fifth Thursday  
Fifth Friday  
32  
33  
34  
35  
36  
37  
38  
39  
40  
41  
Last Day of Month  
First Sunday  
First Monday  
Fifth Saturday  
Last Sunday  
Last Monday  
Last Tuesday  
Last Wednesday  
Last Thursday  
Last Friday  
First Tuesday  
First Wednesday  
First Thursday  
First Friday  
Third Monday  
Third Tuesday  
First Saturday  
Second Sunday  
Second Monday  
Third Wednesday  
Third Thursday  
Third Friday  
62 Fifth Monday  
63 Fifth Tuesday  
Last Saturday  
.
Table 7. T7351 Key Function Summary.  
Definition  
Grouping  
Information  
Button  
Down Arrow  
Lowers setpoint, day, or time. When setting times or temperatures, hold key down to  
continuously decrease value. Also can make temporary change in temperature setpoint.  
Information  
Up Arrow  
Obtains information (where humidity “high-limit” can be set), cycles through setup  
options.  
Raises setpoint, day, or time. When setting times or temperatures, hold key down to  
continuously increase value. Also can make temporary change in temperature setpoint.  
Temperature Occupied  
Heat  
Sets Occupied Heat setpoint.  
Sets Occupied Cool setpoint.  
Sets Not Occupied Heat setpoint.  
Sets Not Occupied Cool setpoint.  
Occupied  
Cool  
Not Occupied  
Heat  
Not Occupied  
Cool  
Set  
Day  
Sets day of week. Tapping key with 'Set Value' segment on increases current day (same  
effect as Up Arrow key).  
Time  
Sets time. Tapping key with “Set Value” segment on increases time in one hour  
increments.  
Override  
Temporary  
Occupied  
Temporary occupied setting for length of time defined by installer. User can modify  
setpoints.  
Temporary Not  
Occupied  
Sets holiday length. User selects number of days (“0”-”99”), or “---” for continuous  
override.  
Schedule  
Day  
Selects day schedule to modify. (Used also with copy key.)  
Occupied  
Selects occupied event start times for specified day. Repeatedly press this key to toggle  
between two occupied events.  
Not Occupied  
Selects not occupied event start times for specified day. Repeatedly press this key to  
toggle between two not occupied events.  
Clear Start Time  
Clears start time for specified period and day.  
Copy  
Copies schedule from one day to another.  
System  
Selects System Mode. Toggles through Em Heat, Off, Cool, and Auto.  
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Table 7. T7351 Key Function Summary. (Continued)  
Grouping  
Button  
Definition  
Schedule  
Fan  
Selects fan operation mode. Toggles between On and Auto.a  
Run Schedule  
Resumes running schedule (cancels Temporary Occupied action, Holiday, and/or  
Temporary setpoint changes.)  
a
On: Continuous fan operation during occupied periods. During not occupied periods and in standby mode when no motion is  
sensed, fan cycles with call for heat or cool.  
Auto: Fan cycles with call for heat or cool during all periods. (See Product Data Sheet, form 63-2605, for more details).  
NOTES: The display returns to default screen after pressing Run Schedule (or after a period of time without keypress):  
ten seconds: when returning from temporary setpoint changes, info screen, temp occ, and temp not occ.  
one minute: when returning from setting clock/day.  
ten minutes: when returning from System Checkout.  
five minutes: when returning from all other modes.  
a. To enter test mode, press upor downuntil the  
Special Functions  
display indicates IN TEST.  
b. To cancel this option, ensure display indicates NO  
TEST.  
Restore Factory Configuration (Run/Clear)  
3.  
Press Run Schedule.  
IMPORTANT  
This operation erases current configuration and  
restores factory defaults for all configuration,  
parameters, setpoints and schedules. To regain the  
old requires device reconfiguration.  
NOTES:  
To verify whether or not the system test is still  
active, repeat the above process.  
The system test times out after ten minutes with no  
key pressed.  
1
.
.
Press both Run Schedule and Clear Start Time.  
The display gives the option to revert to FAC CFG.  
a. To restore the factory defaults, press upor  
downuntil the display indicates YES.  
b. To cancel this option, ensure the display  
indicates NO.  
2
Save User Schedule (Info/Copy)  
Performing this operation saves the current schedule (including  
holidays) to memory, overwriting the old saved schedule:  
1. Press both Info and Copy.  
2. The display gives the option to revert to SAV SHD.  
a. To save the current schedule, press upor  
downuntil the display indicates YES.  
3.  
Press Run Schedule.  
b. To cancel this option, ensure display indicates NO.  
Press Run Schedule.  
Get Factory Schedule (Info/Clear)  
Performing this operation reverts the schedules to the factory  
defaults:  
3.  
Get User Schedule (Info/Run)  
1
.
.
Press both Info and Clear Start Time.  
Getting the user schedule restores the schedule (including  
holidays) from saved memory, overwriting the schedule  
currently in use:  
2
The display gives the option to revert to FAC SCH.  
a. To restore the factory schedule, press upor  
downuntil the display indicates YES.  
b. To cancel this option, ensure display indicates NO.  
Press Run Schedule.  
1
.
.
Press both Run Schedule and Info.  
2
The display gives the option to GET SHD.  
a. To retrieve the saved schedule, press upor  
downuntil the display indicates YES.  
b. To cancel this option, ensure display indicates NO.  
Press Run Schedule  
3.  
Test Mode (Occupied/Not Occupied/  
Schedule Day)  
3.  
OPERATION  
CAUTION  
Possible Equipment Damage.  
Equipment damage can result if compressor is  
cycled too quickly.  
Startup Operation  
Upon initial thermostat power-up, a startup and initialization  
program begins. This startup occurs only on initial power-up.  
After total loss of power for an extended period, the current  
time and day can be lost (requiring reset). However, the  
thermostat retains the user program.  
The minimum off time for compressors is bypassed  
during Test Mode. Equipment damage can occur if the  
compressor is cycled too quickly.  
Use the Test Mode to check the thermostat configurations and  
operation. To start the system test:  
NOTE: With no program set, the thermostat controls to  
the Occupied default setpoints of 70° F (21° C) for  
heat and 75° F (24° C) for cool.  
1
.
Press Schedule Day, Occupied and Not Occupied  
simultaneously.  
The display gives the option to TEST.  
2.  
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NOTE: In the items that follow, the term “error” refers to  
the difference between the measured space tem-  
perature and the current actual space tempera-  
ture setpoint:  
T7351 Relay Logic  
All T7351 model thermostats contain at least four switching  
relays. In conventional applications, the relays control first  
stage cooling, first stage heating, fan, and auxiliary. In heat  
pump applications, the relays control the heat pump  
compressor, changeover, fan, and emergency heat.  
— The Throttling Range (TR), also called Proportional Gain,  
determines the impact of the error on the output signal.  
Decreasing TR amplifies the error effect; that is, for a given  
error, smaller TR causes higher output signal.  
O/B Terminal for Heat or Cool  
Changeover  
The O/B terminal controls heat pump changeover. The default  
operation is for the terminal to be powered when calling for  
heat (or while the most recent call was for heat). This  
corresponds to a typical B terminal.  
The Integral Time (IT), also called Integral Gain,  
determines the impact of the error-over-time on the output  
signal. Error-over-time has two components making up its  
value: amount of time the error exists; and size of the error.  
The higher the IT, the slower the control response. In other  
words, a decrease in IT causes a more rapid change to the  
output signal.  
The Derivative Time (DT), also called Derivative Gain,  
determines the impact of the error rate on the output signal.  
The error rate is how fast the error value changes. It can  
also be the direction the space temperature is going, either  
toward or away from the setpoint, and its speed—rapid or  
slow. A decrease in DT causes, for a given error rate, a  
greater effect on output signal.  
NOTE: The O/B terminal can be configured to operate as  
a typical O terminal (powered on call for cool).  
Emergency Heat  
With the system set for Em Heat, auxiliary heat serves as  
stage one; compressor stages are locked off. The fan cycles  
with the auxiliary heat.  
Recovery Ramping Logic  
Equipment Protection  
The T7351 incorporates a ramping feature that gradually  
changes the space setpoints. During recovery operation, the  
setpoint changes at a rate in degrees per hour depending on  
the outdoor air temperature. If there is no outdoor air  
As part of the operational sequence, the T7351  
microprocessor incorporates cycle rate, and minimum on and  
off times for all heating and cooling stages. This extends  
equipment life as it prevents rapid cycling of equipment.  
temperature sensor available, the minimum ramp rate is used.  
When recovering in heating, the control point raises gradually,  
maximizing the use of the more economical first stage heat to  
bring the sensed temperature to the desired comfort setpoint.  
This minimizes using the typically more expensive later  
stage(s) of heat.  
NOTE: Minimum on and off times are fixed.  
Cycle Rates  
The thermostat control algorithm maintains the temperature by  
cycling stages of heating or cooling to meet setpoint. Cycle  
rates, in cycles per hour (cph) are set in the installer setup.  
NOTE: See Fig. 10 for a pictorial representation of the  
heat ramp rate determination.  
NOTE: Defaults are: heat: 6cph, cool: 3cph.  
Recovery Ramping for Conventional  
Systems  
P+I+D Control  
The T7351 microprocessor-based control requires that the  
user understands temperature control and thermostat  
performance. A conventional electromechanical or electronic  
thermostat does not control temperature precisely at setpoint.  
Typically, there is an offset (droop) in the control point as the  
system load changes. This is a phenomenon that most people  
in the industry know and accept.  
HEAT RECOVERY  
RAMP RATE  
(
DEGREES/HOUR)  
MaxHtRamp  
IMPORTANT  
P+I+D (Loop Tuning) parameters are optimized for  
proper operation of a vast majority of HVAC systems.  
Only when completely certain of necessary and  
proper changes should you alter these values.  
Improper changes result in poor system performance  
and equipment problems such as compressor short  
cycling. Other problems include wide swings in space  
temperature and excessive overdriving of modulating  
outputs.  
MinHtRamp  
OUTDOOR AIR  
TEMPERATURE  
OaTempMinHtRamp  
OaTempMaxHtRamp  
M10109A  
All adjustments to Loop Tuning parameters should be gradual.  
After each change, allow the system to stabilize to accurately  
observe the effects of the change. Then, as needed, make  
further refinements until the system operates as desired.  
Fig. 10. Heat Setpoint Ramping for Conventional Systems.  
NOTES:  
If adjustment of PID parameters is required, use the following:  
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T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
Recovery ramping applies between scheduled  
heat or cool setpoint changes from not occupied to  
standby and not occupied to occupied.  
Other setpoint changes use a setpoint step  
change.  
NOTE: The setpoint used during the cool recovery period  
is similar to the heat mode in Fig. 10, except the  
slope of the line reverses for cooling.  
COOL RECOVERY  
RAMP RATE  
(DEGREES/HOUR)  
Recovery Ramping for Heat Pump  
Systems  
During recovery with heat pump equipment, the heating  
setpoint is split into a heat pump setpoint for compressors, and  
two auxiliary heat setpoints for the auxiliary heat stages. (Refer  
to Fig. 11 for the various setpoints.)  
MaxClRamp  
MinClRamp  
HEAT PUMP SETPOINT  
(FOR COMPRESSORS)  
OCCUPIED  
SETPOINT  
OUTDOOR AIR  
TEMPERATURE  
NORMAL  
RECOVERY RAMP  
OaTempMinClRamp  
OaTempMaxClRamp  
M10111A  
AUX HEAT  
STAGE 2 RAMP  
Fig. 12. Setpoint Ramping Parameters with Ramp Rate  
Calculation.  
NOT OCCUPIED  
SETPOINT  
AUX HEAT  
STAGE 1 RAMP  
SPACE  
TEMPERATURE  
Advantages:  
Comfort setting is achieved at the programmed time and  
maintained regardless of weather conditions; occupants are  
comfortable.  
Drafts from low-temperature discharge air are minimized  
during Occupied periods.  
Use of the more economical first stage of heat is maximized  
during recovery, minimizing use of the expensive later heat  
stage(s).  
Comfort and energy savings can be achieved in both  
heating and cooling.  
RECOVERY TIME  
OCCUPIED  
TIME  
M19877  
Fig. 11. Heat Setpoint Ramping for Heat Pump Systems.  
Heat pump ramping for heating proceeds as  
follows:  
Heat cycling reduced, extending equipment life.  
1
.
The heat pump setpoint begins to ramp until the room  
temperature and the compressor ramp intersect.  
At this point, the heat pump setpoint performs a step  
change to the Occupied (or Standby) setpoint and all  
auxiliary heat stages are disabled.  
2.  
Auxiliary Relay  
The auxiliary relay can be used with a variety of controls:  
Time-of-day (TOD).  
Economizer minimum position control.  
Dehumidification (see Dehumidification section).  
NOTE: The heat pump setpoint remains here for the  
rest of the Not Occupied period.  
3
.
The stage one auxiliary heat ramp is calculated based  
on a steeper slope starting 1° F (0.5° C) below the not  
occupied setpoint.  
When the room temperature intersects this auxiliary heat  
ramp, the first stage of auxiliary heat is enabled.  
The stage two auxiliary heat ramp is calculated based on  
an even steeper slope starting 2° F (1° C) below the not  
occupied setpoint.  
Relay for Time-Of-Day (Table 8)  
Time-of-day (TOD) is the Auxiliary Relay default configuration.  
TOD logic operates strictly according to programming:  
4
.
.
Occupied: Relay contacts closed.  
Not Occupied: Relay contacts open.  
Standby (Scheduled): Relay contacts closed.  
5
6.  
When the room temperature intersects this auxiliary heat  
ramp, the second stage of auxiliary heat is enabled.  
Relay for Economizers  
Mechanical cooling is often used with outside temperatures in  
the 50° F (10° C) to 60° F (16° C) range and humidity below 50  
percent. In central and northern climates, hundreds of hours  
fall into this temperature category. By permitting 80 to 100  
percent outside air into the system, mechanical cooling may  
not be needed at all, particularly during Spring and Fall.  
During the cool recovery period, the setpoint changes at a rate  
in degrees per hour relative to the outdoor air temperature. If  
there is no outdoor air temperature sensor available, the  
minimum ramp rate is used.  
See Fig. 12 for the various setpoints.  
Economizers take advantage of outside air. The typical  
economizer consists of an outside air damper, motor, outdoor  
air changeover control and a minimum position potentiometer.  
The motor controls the dampers. Suitability of the outside air  
for cooling is determined by the outdoor air changeover control.  
NOTE: For cooling, the same method is used in both  
conventional and heat pump systems.  
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The potentiometer adjusts the minimum position of the  
economizer dampers, which provide a minimum amount of  
fresh air for ventilation.  
The T7351 can take advantage of an economizer by closing  
the auxiliary relay contacts to control the economizer minimum  
position potentiometer. (See Table 8 for details.)  
The economizer reduces compressor run time, thereby saving  
energy and extending compressor life. The drawback to using  
the economizer is that during the Not Occupied period, if there  
is no call for cool or outdoor air is not suitable for free cooling,  
the economizer is controlled to minimum position. This position  
allows some percentage of outdoor air to enter the building,  
regardless of air suitability. The situation can cause the heating  
or cooling to run more often than when only suitable air is  
permitted to enter the building.  
— Powered: Allows normal economizer operation.  
— Unpowered: Disables the economizer minimum position.  
The lack of power causes the economizer to drive dampers  
fully closed instead of staying at minimum open position.  
This reduces the possibility of unsuitable outdoor air  
entering the building, which lowers the internal load on the  
HVAC system and saves additional energy.  
Table 8. T7351 Auxiliary Relay Logic (Economizer and TOD)  
Auxiliary Contacts  
Occupancy  
Scheduled Motion Sensor Effective  
Period  
Signal  
Occupancy  
Economizer  
TOD  
Notes  
Occupied  
No Sensor  
Wired  
Occupied  
Closedb  
Closed  
Occupied  
Occupied  
Motion Sensed Occupied  
Closedb  
Closed  
No Motion  
Sensed  
Standby  
Open; Closed only  
during calls for cool  
Open Effective Occupancy is Standby. Standby  
setpoints are used and it assumes that the space  
is unoccupied. Economizer relay is energized  
only on calls for cooling.  
a
Not Occupied  
No Sensor  
Wired  
Not  
Occupied  
Open; Closed only  
during calls for cool  
Open  
a
Occupancy sensor will only be active during  
Open scheduled Occupied periods. During scheduled  
Not Occupied periods, the effective occupancy  
will always be Not Occupied.  
Not Occupied Motion Sensed  
Not  
Occupied  
Open; Closed only  
during calls for cool  
a
Not Occupied  
No Motion  
Sensed  
Not  
Occupied  
Open; Closed only  
Open  
a
during calls for cool  
a
Unless otherwise, noted, Economizer logic ignores calls for heat. The Economizer relay will be energized during calls for cooling.  
b With fan set to AUTO and call for neither heat nor cool, the relay is open in order to disable damper minimum position.  
Other Uses for the Auxiliary Relay  
Default Auxiliary Relay Operations  
Examples of other uses of the auxiliary relay are hot water  
heaters, lighting, or baseboard heat. The additional loads are  
connected to the auxiliary relay contacts on the subbase. The  
contacts are rated for 1.5A at 30 Vac, but can be adapted to  
higher current applications using an external relay  
Unless configured as a stage of heating or cooling, terminals  
W2, W3, and Y3 operate for specific auxiliary functions. Each  
output takes on different auxiliary functions depending on  
configuration for Conventional or Heat Pump operation. See  
Table 9 for details.  
(
See Fig. 13).  
NOTE: The default functions cannot be modified. They  
are limited to firmware version 1.3.0 or higher.  
T7350A,B,D,M SUBBASE  
AUX  
RH  
X
TO  
LOAD  
AUXILIARY  
RELAY  
CONTACT  
1
1
RELAY REQUIRED (R8222 OR SIMILAR).  
M19613  
Fig. 13. Using T7351 Models with an External Relay (with  
loads greater than 1.5A).  
63-2666—03  
16  
href="
T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
Table 9. Default Auxiliary Relay Operations.  
Heat Pump or  
Conventional  
Contact Not Used as  
Heat or Cool Stage  
Contact Configuration of Contact Not Used as Stage  
Heat Pump  
Y3  
Simple  
Dehumidification  
Simple  
Dehumidification  
Time of Day  
Time of Day  
a
a
a
a
a
a
W2 not aux heat  
W3 not  
Economizer  
Time of Day  
Economizer  
Economizer  
Time of Day  
Conventional  
Simple  
Dehumidification  
Simple  
Dehumidification  
Simple  
Dehumidification  
a
a
Y3 not (W3 not)  
Economizer  
Time of Day  
Time of Day  
Economizer  
Time of Day  
Y3 not (W3 used)  
Simple  
Dehumidification  
Simple  
Dehumidification  
Simple  
Dehumidification  
Auxiliary Contact Configuration  
Time of Day  
Economizer  
Hot Gas Bypass  
Dehumidification  
Simple  
Dehumidificationa  
aSimple dehumidification uses a normally closed contact. The relay is closed when humidity is below the high limit. When the  
humidity is above the high limit, the contact is open.  
IMPORTANT  
Dehumidification  
At times during Reheat dehumidification, the T7351  
There are five methods through which the T7351 can control  
for dehumidification. Three of them modify the control  
algorithm, thus providing limited dehumidification through  
cooling. The other two use the auxiliary output to control  
another device.  
operates heating and the cooling simultaneously. This  
is normal.  
NOTES:  
The heat stage never energizes during Reheat if  
more than one cool stage is on.  
Reheat mode cannot occur during heating.  
NOTE: The dehumidification high limit can be set within  
the range of 10 to 90 percent relative humidity.  
RESET TEMP SETPT  
The room temperature set point resets to a specified number of  
degrees below the actual set point when room relative humidity  
Control Through Cooling  
Configure using some combination of the following:  
(RH) rises above humidity high limit. The default value is 2  
Minimum On.  
Reheat.  
Reset.  
degrees.  
Though this may not technically reduce RH, it reduces the dew  
point to provide the customer with a sense of comfort due to a  
lower temperature setting in the room.  
NOTES:  
These methods operate only during cooling.  
Selecting both Reheat and Reset can cause  
frequent setpoint adjustments. This selection  
is not recommended.  
As long as RH stays above humidity high limit, this set point is  
maintained.  
NOTE: Hysteresis and a minimum timer prevent the set  
point from short interval alternation (between  
standard and reset set points).  
MIN ON TIME  
Dehumidifies by increasing the compressor minimum on time  
(normally 3 minutes) by a programmable amount. This is useful  
with oversized systems in that it forces the coils to cool to a  
point where dehumidification can occur.  
Options Utilizing Auxiliary Output  
There are two dehumidification options that utilize the auxiliary  
NOTES:  
output. They are:  
— Simple Dehumidification.  
— Hot Gas Bypass Dehumidification.  
Can force wider temperature swings by cooling  
when setpoint control does not require it.  
The minimum on time can be set within the range  
of 5 to 15 minutes.  
Hysteresis and a minimum timer are used to  
ensure this behavior does not change with every  
equipment cycle.  
SIMPLE DEHUMID(IFICATION)  
The auxiliary output:  
Energizes when RH rises above humidity high limit.  
De-energizes when RH drops below humidity high limit.  
NOTES:  
REHEAT  
5% Hysteresis and a minimum timer prevent short  
cycling of this output.  
Unlike Dehumid Hot Gas BP the relay remains  
energized during calls for multiple cooling stages.  
Dehumidifies by operating cooling during typical off time. The  
T7351 maintains the proper setpoint by running the heat at the  
same time.  
DEHUMID HOT GAS BP  
The auxiliary output operates as shown in Table 10.  
17  
63-2666—03  
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T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
Table 10. Hot Gas Bypass Dehumidification Logic.  
Auxiliary output during call for multiple cooling stages for two  
reasons:  
Humidity  
High  
Cooling Stages Active  
more than one  
one or less  
Auxiliary Output  
De-energized  
Energized  
1.  
This method assumes that the cooling provides  
dehumidification.  
2.  
Multiple cooling stages probably provide necessary  
dehumidification.  
High  
Low  
more than one  
one or less  
De-energized  
De-energized  
NOTE: Hysteresis and a minimum timer prevent short  
cycling of this output.  
Low  
TROUBLESHOOTING GUIDE (TABLE 11)  
Table 11. Troubleshooting Information.  
Symptom  
Possible Cause  
Action  
Display will not  
come on.  
Thermostat is not being powered.  
Check that X terminal is connected to the system  
transformer.  
Check for 24 Vac between X and RH or RC terminals.  
If missing 24 Vac:  
Check if circuit breaker is tripped; if so, reset circuit  
breaker.  
Check if system fuse is blown; if so, replace fuse.  
Check if the HVAC equipment power switch is in the Off  
position; if so, set to the On position.  
Check wiring between thermostat and HVAC equipment.  
Replace broken wires and tighten loose connections.  
If 24 Vac is present, proceed with troubleshooting.  
Temperature  
display is incorrect.  
Thermostat is configured for ° F or ° C display. Press both Run Schedule and Copy, then reconfigure the  
display.  
Bad thermostat location.  
Relocate the thermostat.  
Display shows three dashes and a degree sign T7351 is set for the remote sensing and sensor is missing or  
(
all systems shut down).  
circuit is either open or shorted.  
Check the temperature setpoints:  
Temperature  
settings will not  
change.  
Upper or lower temperature limits were  
reached.  
Heating limits are 40° to 90° F (4° to 32° C)  
Cooling limits are 45° to 99° F (7° to 37° C)  
(
Example: Cannot  
Occupied setpoint temperature range stops  
were configured.  
Check setpoint stops. If necessary, reconfigure the stop(s).  
set heating higher  
or cooling lower.)  
Keypad is locked. When a locked key is  
pressed, LOCKED appears momentarily on the  
LCD.  
Change keypad lock level.  
Room temperature Remote temperature sensing is not working.  
is out of control.  
Check all remote sensors.  
Heat will not come No power to the thermostat.  
on.  
Check that X terminal is connected to the system  
transformer.  
Check for 24 Vac between X and RH terminals.  
If missing 24 Vac:  
Check if circuit breaker is tripped; if so, reset circuit  
breaker.  
Check if system fuse is blown; if so, replace fuse.  
Check if the HVAC equipment power switch is in the Off  
position; if so, set to the On position.  
Check wiring between thermostat and HVAC equipment.  
Replace broken wires and tighten loose connections.  
If 24 Vac is present, proceed with troubleshooting.  
Thermostat minimum off time is activated.  
System selection is set to Off or Cool.  
Wait up to five minutes for the system to respond.  
Configure heating response.  
Set system selection to Heat or Auto.  
DAT high limit has been reached, or  
OAT lockout is engaged.  
If the setpoints are correct, do nothing.  
Adjust or disable DAT high limit and/or OAT lockout.  
Check HVAC equipment to ensure proper operation.  
63-2666—03  
18  
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T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
Table 11. Troubleshooting Information. (Continued)  
Symptom  
Possible Cause  
Action  
Cooling will not  
come on.  
No power to the thermostat.  
Check that X terminal is connected to the system  
transformer.  
Check for 24 Vac between X and RC terminals.  
If missing 24 Vac:  
Check if circuit breaker is tripped; if so, reset circuit  
breaker.  
Check if system fuse is blown; if so, replace fuse.  
Check if the HVAC equipment power switch is in the Off  
position; if so, set to the On position.  
Check wiring between thermostat and HVAC equipment.  
Replace broken wires and tighten loose connections.  
If 24 Vac is present, proceed with troubleshooting.  
Thermostat minimum off time is activated.  
System selection is set to Off or Heat.  
Wait up to five minutes for the system to respond.  
Configure cooling response.  
Set system selection to Cool or Auto.  
DAT low limit has been reached, or  
OAT lockout is engaged.  
If the setpoints are correct, do nothing.  
Adjust or disable DAT low limit and/or OAT lockout.  
Check HVAC equipment to ensure proper operation.  
System indicator  
The call for heat or cool is not yet given.  
Check if any stage indicators (dots next to the system  
indicator) are displayed. With no display of stage indicators,  
no call for cool/heat via relay is yet given.  
(
flame: heat,  
snowflake: cool) is  
displayed, but no  
warm or cool air is  
coming from the  
registers.  
Conventional heating equipment turns the fan Wait one minute after seeing the on indicator and then  
on only after the furnace has warmed to a  
setpoint.  
check the registers.  
Heating or cooling equipment is not operating. Verify operation of heating or cooling equipment in Test  
Mode.  
WIRING DIAGRAM (FIGURES 14 AND 15)  
TR23-H REMOTE SENSOR  
OUTDOOR  
AIR  
SENSOR  
COMPRESSOR  
CONTACTOR 2  
1
2
3
4
5
6
7
8
9
10 11 12  
DISCHARGE  
AIR  
SENSOR  
HEAT  
RELAY 3  
HEAT  
RELAY 2  
SUBBASE  
T5  
T6  
T7  
T4  
T3  
OS  
M
OS  
M
AS  
X
AS  
W3/Y4 Y3  
W2  
Y1  
Y2  
G
5
HS  
HC  
HP  
RH RC AUX W1  
COMPRESSOR  
CONTACTOR 3  
3
HEAT  
RELAY 1  
FAN  
RELAY  
HUMIDITY  
SENSOR  
MOTION  
SENSOR  
COMPRESSOR  
CONTACTOR 1  
4
L2  
L1  
1
2
ECONOMIZER  
(
HOT)  
1
2
3
4
5
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
ENSURE TRANSFORMER IS SIZED TO HANDLE THE LOAD.  
HEAT/COOL SYSTEMS WITH ONE TRANSFORMER REQUIRE THE FACTORY-INSTALLED JUMPER.  
USE ECONOMIZER INSTRUCTIONS FOR INSTALLATION DIRECTIONS.  
WHEN USING THE TR23-H FOR HUMIDITY SENSING THERE IS NO NEED TO WIRE HC TERMINAL  
BECAUSE THE T3 TERMINAL IS INTERNALLY TIED TO HC, WHICH IS ALSO TIED TO TERMINAL 1  
COMMON AT THE SENSOR.  
M29255  
Fig. 14. Typical Hookup of T7351F2010 in Three-Stage Heat and Three-Stage Cool Conventional System with One  
Transformer.  
19  
63-2666—03  
href="
T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT  
TR23-H REMOTE SENSOR  
OUTDOOR  
AIR  
SENSOR  
HEAT  
RELAY 2  
1
2
3
4
5
6
7
8
9
10 11 12  
DISCHARGE  
AIR  
SENSOR  
COMPRESSOR  
COMPRESSOR  
CONTACTOR 2  
CONTACTOR 4  
W3/Y4 Y3  
SUBBASE  
T5  
T6  
T7  
T4  
T3  
OS  
M
OS  
M
AS  
X
AS  
W2  
Y1  
Y2  
G
HS  
HC  
HP  
RH RC AUX W1  
COMPRESSOR  
CONTACTOR 3  
5
3
HEAT  
RELAY 1  
FAN  
RELAY  
HUMIDITY  
SENSOR  
MOTION  
SENSOR  
COMPRESSOR  
CONTACTOR 1  
4
L2  
L1  
1
2
ECONOMIZER  
(
HOT)  
1
2
3
4
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
ENSURE TRANSFORMER IS SIZED TO HANDLE THE LOAD.  
HEAT/COOL SYSTEMS WITH ONE TRANSFORMER REQUIRE THE FACTORY-INSTALLED JUMPER.  
USE ECONOMIZER INSTRUCTIONS FOR INSTALLATION DIRECTIONS.  
5
WHEN USING THE TR23-H FOR HUMIDITY SENSING THERE IS NO NEED TO WIRE HC TERMINAL  
BECAUSE THE T3 TERMINAL IS INTERNALLY TIED TO HC, WHICH IS ALSO TIED TO TERMINAL 1  
COMMON AT THE SENSOR.  
M29254  
Fig. 15. Typical Hookup of T7351F2010 in Two-Stage Heat and Four-Stage Cool Conventional System.  
TR23-H REMOTE SENSOR  
OUTDOOR  
AIR  
SENSOR  
COMPRESSOR  
CONTACTOR 2  
1
2
3
4
5
6
7
8
9
10 11 12  
DISCHARGE  
AIR SENSOR  
AUX HEAT  
STAGE 1  
SUBBASE  
T5  
T6  
T7  
T4  
T3  
OS  
M
OS  
M
AS  
X
AS  
W2  
W1  
Y2  
G
4
HS  
HC  
HP  
RH RC AUX O/B Y1  
2
CHANGE-  
OVER  
FAN  
RELAY  
HUMIDITY  
SENSOR  
MOTION  
SENSOR  
COMPRESSOR  
CONTACTOR 1  
3
L2  
L2  
L1  
1
ECONOMIZER  
1
L1  
HOT)  
(
(HOT)  
HEATING  
TRANSFORMER  
COOLING  
TRANSFORMER  
1
2
3
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.  
WHEN INSTALLED ON A SYSTEM WITH TWO TRANSFORMERS, REMOVE THE FACTORY-INSTALLED JUMPER.  
USE ECONOMIZER INSTRUCTIONS FOR INSTALLATION DIRECTIONS.  
4
WHEN USING THE TR23-H FOR HUMIDITY SENSING, THERE IS NO NEED TO WIRE THE HC TERMINAL  
BECAUSE THE T3 TERMINAL IS INTERNALLY TIED TO HC, WHICH IS ALSO TIED TO TERMINAL 1  
COMMON AT THE SENSOR.  
M29323  
Fig. 16. Typical hookup of T7351F2010 in two-stage heat and two-stage cool heat pump system with two transformers.  
Automation and Control Solutions  
Honeywell International Inc.  
1
985 Douglas Drive North  
®
U.S. Registered Trademark  
© 2013 Honeywell International Inc.  
3-2666—03 M.S. Rev. 12-13  
Printed in United States  
Golden Valley, MN 55422  
customer.honeywell.com  
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