Honeywell Thermostat T7351 Users Manual 62 0258 Commercial Programmable

2015-01-23

: Honeywell Honeywell-Honeywell-Thermostat-T7351-Users-Manual-262219 honeywell-honeywell-thermostat-t7351-users-manual-262219 honeywell pdf

Open the PDF directly: View PDF .
Page Count: 12

Download
Open PDF In Browser	View PDF

T7351 Commercial Programmable
Thermostat

FOR SINGLE- OR MULTI-STAGE CONVENTIONAL/HEAT PUMP
SYSTEMS
INSTALLATION INSTRUCTIONS

APPLICATION
The T7351 Commercial Programmable Thermostat
controls 24 Vac commercial single zone heating,
ventilating and air conditioning (HVAC) equipment. The
T7351 consists of a thermostat and subbase. The
thermostat includes the display and keypad for 7-day
programming. The subbase includes equipment control
connections. The subbase mounts on the wall and the
thermostat mounts to the subbase.

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.
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.

INSTALLATION
When Installing this Product...
1.
2.
3.
4.

Read these instructions carefully. Failure to follow
them could damage the product or cause a hazardous condition.
Check ratings given in instructions and on the
product to ensure the product is suitable for your
application.
Installer must be a trained, experienced service
technician.
After installation is complete, check out product
operation as provided in these instructions.

CAUTION

Location
Do not install the thermostat where it can be affected by:
— 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.
IMPORTANT
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. The
cable shield must be grounded only at the controlled equipment case.

Subbase
WHEN USED TO SENSE ROOM TEMPERATURE
Install the thermostat about 5 ft. (1.5m) above the floor in
an area with good air circulation at average temperature.
(See Fig. 1.)
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.
Install the remote-mounted sensor(s) about 5 ft. (1.5m)
above the floor in an area with good air circulation at
average temperature (See Fig. 1).
If multiple remote sensors are required, they must be
arranged in a temperature averaging network consisting
of four sensors (See Fig. 2).
NOTE: Only T7770 models with no setpoint adjustment
can be used for temperature averaging.

Electrical Shock or Equipment Damage
Hazard. Can shock individuals or short
equipment circuitry.
Disconnect power supply before installation.

62-0258

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT

SUBBASE
T4

YES

T7770A
T

T3
T7770A

5 FEET
(1.5 METERS)

T7770A

T7770A
T

M4823A

Fig. 1. Typical location of thermostat or
remote-mounted sensor.

Mounting Subbase
The subbase mounts horizontally.

M19606A

Fig. 2. Four T7770A Sensors providing temperature
averaging network for T7351 Thermostat.

IMPORTANT
• When using the internal temperature or humidity
sensor, the device must be mounted horizontally
(with the LCD facing upwards). Precise leveling
is not needed.
• When using remote room temperature and
humidity sensors, thermostat mounting
orientation does not matter.

WIRES THROUGH WALL
MOUNTING
HOLES

Wall mounting (using standard drywall screws) is
standard. Mounting to a 2 in. by 4 in. (50.8 mm by 101.6
mm) wiring box can be accomplished:
— for a horizontal box, no extra hardware is required.
— for a vertical box, part 209651A is required.
— Mount to European standard wall box (having 2.4 in.
(60.3 mm) between mounting screws in a horizontal
line) with or without adaptive hardware.
1.

WALL
ANCHORS
(2)

Position and level the subbase.

MOUNTING
SCREWS

NOTE: A level wallplate is only for appearance.
The thermostat functions properly when
not level.
2.
3.

4.
5.
6.
7.

Use a pencil to mark the mounting holes. (See
Fig. 3).
Remove the subbase from the wall and drill two 3/
16 in. (4.8 mm) holes in the wall (if drywall) as
marked. For firmer material such as plaster or
wood, drill two 7/32 in. (5.6 mm) holes.
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.
Loosely insert the mounting screws into the holes.
Tighten mounting screws.

62-0258

M19608

Fig. 3. Mounting the subbase.

Mounting Thermostat on Subbase (Fig. 4)
With the subbase installed, mount the thermostat:
1. Engage top subbase tabs into the thermostat top.
2. Swing the thermostat down.
3. Press the lower edge of the case to latch.
NOTE: To remove the thermostat from the wall, first pull
out at the bottom of the thermostat; then remove
the top.

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT

A. ENGAGE TABS AT TOP OF THERMOSTAT AND SUBBASE OR WALLPLATE.

SETTINGS
Using Thermostat Keys
The thermostat keys are used to:
• set current time and day,
• program times and setpoints for heating and cooling,
• override the program temperatures,
• display present setting,
• set system and fan operation.
NOTE: See Fig. 5 for keypad information.

Setting Temperature
B. PRESS LOWER EDGE OF CASE TO LATCH.

Refer to Table 2 for the default temperature setpoints. To
set the Occupied and Not Occupied Heat and Cool
setpoints, simply press the Heat and Cool button under
the Occupied or Not Occupied area of the keypad. To set
the Standby Heat setpoint, press both the Occupied and
Not Occupied Heat buttons simultaneous. To set the
Standby Cool setpoint, press the Occupied Cool and Not
Occupied Heat buttons simultaneously.

Setting System and Fan
System default setting is Auto. Fan default setting is On.
NOTE: Use System and Fan keys to change settings.

System Settings
M19609

Fig. 4. Mounting thermostat on subbase.

Wiring
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.
IMPORTANT
All wiring must comply with local electrical codes
and ordinances.
NOTE: Maximum (and recommended) wire size is 18gauge. Do not use wire smaller than 22-gauge.
1.
2.
3.
4.

Loosen subbase terminal screws and connect system wires.
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.

— Auto: Thermostat automatically changes between
heating and cooling based on indoor temperature.
— Cool: Thermostat controls cooling.
— Off: Heating, cooling, and fan are all off.
— Heat: Thermostat controls heating.
— Em Heat: Auxiliary heat serves as first stage.
Compressor stages are locked off.

Fan Settings
— On: See Table 1.
— Auto: Fan always cycles with call for heat or cool.
— Conventional: The equipment (i.e. plenum switch)
controls fan operation in heat mode. Thermostat
controls fan operation in cool mode.
— Electric Heat: Thermostat controls fan operation in
both heat and cool modes.
NOTES: 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.
Table 1. Fan On Control Logic.
Occupancy
Scheduled

Call for Heat/Cool

Sensor Signal

Yes

Occupied

Standby

Off a

Standby

—

Not Occupied

—

Off a

In heat mode, when set for conventional heat, the equipment (i.e. plenum switch) could power the fan despite
the T7351.

62-0258

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT

Set Day/Time

Temperature
Occupied
HEAT

Not Occupied
COOL

HEAT

COOL

Time

System

Fan

Run

Copy

HEAT COOL

ON AUTO

Schedule

Day

Clear
Occupied Not Occupied Start Time

Override
Temporary Temporary
Occupied Not Occupied

Day

M19610

Fig. 5. Thermostat key locations.

INSTALLER SETUP

Setup Using Keypad

For most applications, the thermostat factory settings do
not need to be changed. Review the factory settings in
Table 2.
NOTE: When power is first applied to the thermostat, the
display will show all segments (see Fig. 6).

The installer uses the Installer Setup to customize the
thermostat to specific systems
A combination of key presses are required to use the
Installer Setup feature:
1. To enter the Installer Setup, press and hold both the
Run Schedule and the Copy keys until DEGREES
00 (or DEGREES 01) displays.

Table 2. Default Setpoints.
Control

Occupied

Not Occupied

NOTE: Installer Setup will display WAIT and is
unavailable for 30 seconds after power up.

Standby

Heating

70° F (21° C) 55° F (13° C)

67° F (19° C)

Cooling

75° F (24° C) 85° F (29° C)

78° F (26° C)

2. To advance to the next Installer Setup number,
press
.
NOTE: Pressing Run/Copy again while in this
mode displays the T7351 firmware version
number.

Temporary Standby Set Set Schedule Room
Not Occupied12 StartTime
AM
PM

System
Em Heat

MonTueWedThuFri SatSunHol MinsDays
Fan
OnAuto
Off Cool Auto Dehumid
M19611

3.
4.
5.
6.

Fig. 6. LCD display of all segments.

CAUTION

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.

To return to a Setup item, cycle through the options.
To change a setting, use the up ! or down " key.
To exit the Installer Setup, press Run Schedule.
Display prompts SAV CFG (save configuration).
a. If you want to save the new configuration, use
the up ! 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.

NOTE: Installer Setup is automatically exited after five
minutes with no key pressed. Upon this automatic exit, all changes are lost.

Configuration
Configuration can be done with the keypad using the
Installer Setup (ISU).

62-0258

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT

Table 3. Installer Setup.
Text

Default

Choices

Notes

DEGREES 0

0 -1

Degree Temperature Format
0: Degrees F
1: Degrees C

CLOCK

0-1

Clock Display Format
0: 12 hour
1: 24 hour

KEYLOCK 0

0-3

Keypad Lockout Level
0: None
1: Lockout all keys except Set Day, Set Time, Set Date, Set Holidays,
Temporary Occupied, Temporary Not Occupied, System, Fan, Up, Down and
Information
2: Lockout all keys except Set Day, Set Time. Set Date, Set Holidays,
Temporary Occupied, Temporary Not Occupied, Up, Down and Information
3: Lockout all keys except Information

HEATPMP 0

0-2

Application Type Selection
0: Conventional
1: Heat Pump - Cooling (Energize O/B on call for cool)
2: Heat Pump - Heating (Energize O/B on call for heat)

COOLSTG 1

0-4

Number of Cooling Stages
0: 0 Stages of Cooling
1: 1 Stages of Cooling
2: 2 Stages of Cooling
3: 3 Stages of Cooling
4: 4 Stages of Cooling (W3 will be used as 4th stage relay)

HEATSTG 1

0-3

Number of Heating Stages
0: 0 Stages of Heating
1: 1 Stages of Heating
2: 2 Stages of Heating (This is the max if 4 cooling stages is selected)
3: 3 Stages of Heating

AUX STG

0-2

Only shown when Heat Pump is selected
0: 0 Aux Stages
1: 1 Aux Stages
2: 2 Aux Stages

AUX CON

0-3

Aux Contact Functionality
0: Time of Day
1: Economizer
2: Dehumid - Hot Gas Bypass
3: Simple Dehumid

WALLMOD 0

0-3

Remote Room Sensor Selection
0: Local sensor only
1: T7770A/D (Remote Sensor, No Remote Setpoint, Bypass 0)
2: T7770B/C (Remote Sensor, Remote Setpoint, Bypass 0)
3: T7771 (Remote sensor, Remote Setpoint, Bypass 1)
(Display only if sub-base 2, 3, 4+)
(This item is not displayed when

OATSENS 0

0-1

Outdoor Air Sensor Selection
0: None
1: Remote Outdoor Air Sensor

DATSENS 0

0-1

Discharge Air Sensor Selection
0: None
1: Remote Discharge Air Sensor

HUMSENS 0

0-2

Room Humidity Sensor selection
0: None
1: On Board Sensor
2: Remote Sensor

OCCSENS 0

0-1

Occupancy Sensor Selection
0: None
1: Remote Occ Sensor

FAN HT

0-1

Fan Operation on Heat
0: Conventional (Equipment controls Fan)
1: Electric (Thermostat turns on Fan with call for Heat)

62-0258

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT
Table 3. Installer Setup. (Continued)
Text

Default

Choices

Notes

XFAN HT

YES

YES or NO

Extended Fan on Heat
NO: None
YES: 90 seconds

XFAN CL

YES or NO

Extended Fan on Cool
NO: None
YES: 40 seconds

STRTDEL

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

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

1-8

Temporary Occupied Duration
1 to 8 hours

TMP CAL

-4 - 3

Temporary Display Adjustment
0 - 3 = 0 to 3 DDF
4 - 7 = -4 to -1 DDF

MINCOOL 45° F
(7° C)

45° - 99° F
(7° - 37° C)

Min Cool Setpoint

MAXHEAT 90° F
(32° C)

40° - 90° F
(4° - 32°)

Max Heat Setpoint

HEATLCK

YES or NO

Heating Lockout (Only displayed if Outdoor Air Sensor is selected)
NO: None
YES: Enabled

HTLCKSP

70° F
(21° C)

-40° - 120 ° F
(-40° - 49° F)

Heating Lockout Temperature
(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
(2° C)

-40° - 120° F
(-40° - 49° C)

Cooling Lockout Temperature
(Display only if Remote Outdoor Air Sensor is configured)

DAT LL

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)

DAT HL

YES or NO

Discharge High Limit (Only displayed if Discharge Air Sensor is Selected)
NO: None
YES: Enabled

DATHLSP

110° F
(43° C)

65° - 140° F
(18° - 60° C)

Discharge High Temperature Limit
(Display only if Discharge Sensor is configured)

0-5

Dehumidification
0: None
1: MinOn Time
2: Reset Temp Setpoint
3: Reset w/ MinOn
4: Reheat
5: Reheat w/ Min On

DEHUMID 0

DEH MIN

5 - 15

Dehumidify Minutes On

DEH TMP

1-5

Dehumidify Temp Reset

MINHTRT

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

62-0258

0° F
-20° - 120° F
(-18° C) (-29° - 49° C)

Minimum Heat Outdoor Air Temperature (Only Displayed if Outdoor Sensor is
Selected)
6

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT
Table 3. Installer Setup. (Continued)
Text

Default

Choices

Notes

MAXHTOA 40° F
(4° C)

-20° - 120° F
(-29° - 49° C)

Maximum Heat Outdoor Air Temperature (Only Displayed if Outdoor Sensor is
Selected)

MINCLRT

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
(32° C)

-20° - 120° F
(-29° - 49° C)

Minimum Cool Outdoor Air Temperature (Only Displayed if Outdoor Sensor is
Selected)

MAXCLOA 70° F
(21° C)

-20° - 120° F
(-29° - 49° C)

Maximum Cool Outdoor Air Temperature (Only Displayed if Outdoor Sensor is
Selected)

DSTMON1 3

0 - 12

DLS Spring Month

DSTDAY1

0 - 31, 32 - 74

DLS Spring Day
0 - 31 = Day of Month
32 = Last Day of Month
33 = First Sunday
etc…

DSTMON2 11

0 - 12

DLS Fall Month

DSTDAY2

0 - 31, 32 - 74

DLS Fall Day
0 - 31 = Day of Month
32 = Last Day of Month
33 = First Sunday
etc…

HT RESP

0-3

0: Standard - 3 cph
1: Medium - 6 cph
2: Fast - 9 cph
3: Super Fast - 20 cph

CL RESP

0-1

0: Standard - 3 cph
1: Fast - 4 cph

(DayLight Savings options only display when Date is valid)
40

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:
1.
2.
3.
4.
5.

Press Set Day and Set Time keys simultaneously.
Use the Up/Down keys to set the date to YES, then
press the
key.
Use the Up/Down keys to set the month, then press
the
key.
Use the Up/Down keys to set the day, then press
the
key (See Table 4 for valid day choices).
Use the Up/Down keys to set the year, then press
the
key.

Holidays can be set in the following manner:
1. Press the “Temporary Occupied” and Temporary
Not Occupied” keys simultaneously.
2. The month (MON) of the first holiday is then displayed (00 means the holiday is ignored).
3. Use the Up/Down keys to set the month, then press
the
key.
4. Use the Up/Down keys to set the day, then press
the
key (see Table 4 for valid day choices).
5. 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).

Table 4. Valid Day Values.
Value

Description

1 to 31 Day of month

Value
42

Description

Value

Description

Value

Description

Second Tuesday

Third Saturday

Fifth Wednesday

Last Day of Month 43

Second Wednesday

Fourth Sunday

Fifth Thursday

First Sunday

Second Thursday

Fourth Monday

Fifth Friday

First Monday

Second Friday

Fourth Tuesday

First Tuesday

Second Saturday

Fourth Wednesday 68

Fifth Saturday
Last Sunday

First Wednesday

Third Sunday

Fourth Thursday

Last Monday

First Thursday

Third Monday

Fourth Friday

Last Tuesday

First Friday

Third Tuesday

Fourth Saturday

Last Wednesday

First Saturday

Third Wednesday

Fifth Sunday

Last Thursday

Second Sunday

Third Thursday

Fifth Monday

Last Friday

Second Monday

Third Friday

Fifth Tuesday

Last Saturday

62-0258

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT

Table 5. T7351 Key Function Summary.
Grouping
Information

Button
Down Arrow

Information
Up Arrow

Temperature

Set

Override

Schedule

Definition
" 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.
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.

Occupied
Heat

Sets Occupied Heat setpoint.

Occupied
Cool

Sets Occupied Cool setpoint.

Not
Occupied
Heat

Sets Not Occupied Heat setpoint.

Not
Occupied
Cool

Sets Not Occupied Cool setpoint.

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.

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.

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, Heat, Off, Cool, and Auto.

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.)

On: Continuous fan operation (occupied and standby). During not occupied periods, 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.

Special Functions
Restore Factory Configuration (Run/Clear)
IMPORTANT
This operation erases current configuration and
restores factory defaults for all configuration,
parameters, setpoints and schedules. To regain
the old requires device reconfiguration.

1. Press both Run Schedule and Clear Start Time.
2. The display gives the option to revert to FAC CFG.
a. To restore the factory defaults, press up ! or
down " until the display indicates YES.
b. To cancel this option, ensure the display
indicates NO.
3. Press Run Schedule.

62-0258

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT

Get Factory Schedule (Info/Clear)
Performing this operation reverts the schedules to the
factory defaults:
1. Press both Info and Clear Start Time.
2. The display gives the option to revert to FAC SCH.
a. To restore the factory schedule, press up ! or
down " until the display indicates YES.
b. To cancel this option, ensure display indicates
NO.
3. Press Run Schedule.

Test Mode (Occupied/Not Occupied/Schedule
Day)

CAUTION

Possible Equipment Damage.
Equipment damage can result if compressor is
cycled too quickly.
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:
1. Press Schedule Day, Occupied and Not Occupied
simultaneously.
2. The display gives the option to TEST.
a. To enter test mode, press up ! or down " until
the display indicates IN TEST.
b. To cancel this option, ensure display indicates
NO TEST.
3. Press Run Schedule.
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.

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 up ! or
down " until the display indicates YES.
b. To cancel this option, ensure display indicates
NO.
3. Press Run Schedule.

DEHUMIDIFICATION
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.
NOTE: The dehumidification high limit can be set within
the range of 10 to 90 percent relative humidity.

Control Through Cooling
Configure using some combination of the following:
— Minimum On.
— Reheat.
— Reset.
NOTES:
—
—

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.
NOTES:
—
—
—

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.

Reheat
Dehumidifies by operating cooling during typical off time.
The T7351 maintains the proper setpoint by running the
heat at the same time.
IMPORTANT
At times during Reheat dehumidification, the
T7351 operates heating and the cooling simultaneously. This is normal.
NOTES:
—
—

Get User Schedule (Info/Run)
Getting the user schedule restores the schedule
(including holidays) from saved memory, overwriting the
schedule currently in use:
1. Press both Run Schedule and Info.
2. The display gives the option to GET SHD.
a. To retrieve the saved schedule, press up ! or
down " until the display indicates YES.
b. To cancel this option, ensure display indicates
NO.
3. Press Run Schedule

These methods operate only during cooling.
Selecting both Reheat and Reset options can
cause frequent setpoint adjustments. This
selection is not recommended.

The heat stage never energizes during
Reheat if more than one cool stage is on.
Reheat mode cannot occur during heating.

Reset Temp SetPt
The room temperature set point resets to a specified
number of degrees below the actual set point when room
relative humidity (RH) rises above humidity high limit set
point.
Though this may not technically reduce relative humidity
in the room, it reduces the dew point to provide the
customer with a sense of comfort due to a lower
temperature setting in the room.
As long as RH stays above humidity high limit set point,
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).
9

62-0258

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT

Options Utilizing Auxiliary Output

Dehumid Hot Gas BP

There are two dehumidification options that utilize the
auxiliary output. They are:
— Simple Dehumidification.
— Hot Gas Bypass Dehumidification.

The auxiliary output operates as shown in Table 6.

Simple Dehumid(ification)

High

more than one

De-energized

The auxiliary output:
— Energizes when RH rises above humidity high limit.
— De-energizes when RH drops below humidity high
limit.

High

one or less

Energized

Low

more than one

De-energized

Low

one or less

De-energized

NOTES:
—
—

Table 6. Hot Gas Bypass Dehumidification Logic.
Humidity

Cooling Stages Active Auxiliary Output

Auxiliary output during call for multiple cooling stages for
two reasons:
1. This method assumes that the cooling provides
dehumidification.
2. Multiple cooling stages probably provide necessary
dehumidification.
3. Hysteresis and a minimum timer prevent short
cycling of this output.

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.

WIRING DIAGRAMS
OUTDOOR
AIR
SENSOR

T7770 REMOTE SENSOR

COMPRESSOR
CONTACTOR 2
DISCHARGE
AIR
SENSOR

HEAT
RELAY 2

SUBBASE
T5

AUX

2
HUMIDITY
SENSOR

COMPRESSOR
CONTACTOR 1

3
1

FAN
RELAY

HEAT
RELAY 1

MOTION
SENSOR

L2
1
L1
(HOT)

ECONOMIZER

L1
(HOT)
HEATING
TRANSFORMER

COOLING
TRANSFORMER

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.

M25324

Fig. 7. Typical hookup of T7351F2010 in two-stage heat and two-stage cool heat pump system with two
transformers.

OUTDOOR
AIR
SENSOR

T7770 REMOTE SENSOR

HEAT
RELAY 2
DISCHARGE
AIR
SENSOR

COMPRESSOR
CONTACTOR 4

COMPRESSOR
CONTACTOR 2

SUBBASE
T5

W3/Y4 Y3

AUX

G
COMPRESSOR
CONTACTOR 3

HUMIDITY
SENSOR

MOTION
SENSOR

HEAT
RELAY 1

4
1

FAN
RELAY

COMPRESSOR
CONTACTOR 1

ECONOMIZER

L1
(HOT)

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.

M19768A

Fig. 8. Typical hookup of T7351F201U in two-stage heat and four-stage cool conventional system.
62-0258

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT

OUTDOOR
AIR
SENSOR

T7770 REMOTE SENSOR

DISCHARGE
AIR
SENSOR

COMPRESSOR
CONTACTOR 2

ECONOMIZER
HEAT
RELAY 3

HEAT
RELAY 2

SUBBASE
T5

AUX W3/Y4 Y3

AUX

G
COMPRESSOR
CONTACTOR 3

HUMIDITY
SENSOR

MOTION
SENSOR

HEAT
RELAY 1

FAN
RELAY

COMPRESSOR
CONTACTOR 1

L2
L1
(HOT)

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.

M25319

Fig. 9. Typical hookup of T7350F2010 in three-stage heat and three-stage cool conventional system
with one transformer.

TROUBLESHOOTING GUIDE (TABLE 7)
Table 7. 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 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 T7351 is set for remote sensing and sensor is missing or circuit
degree sign (all systems shut
is either open or shorted.
down).
Temperature
settings will not
change.
(Example:
Cannot set
heating higher or
cooling lower.)

Upper or lower temperature limits
were reached.

Check the temperature setpoints:
• Heating limits are 40 to 90°F (7 to 31°C)
• Cooling limits are 45 to 99°F (9 to 37°C)

Occupied setpoint temperature
range stops were configured.

Check setpoint stops. If necessary, reconfigure the stop(s).

Keypad is locked. When a locked
key is pressed, LOCKED appears
momentarily on the LCD.

Press both Run Schedule and Copy, then change keypad lock
level.

Room
temperature is
out of control.

Remote temperature sensing is not Check all remote sensors.
working.

62-0258

T7351 COMMERCIAL PROGRAMMABLE THERMOSTAT
Table 7. Troubleshooting Information. (Continued)
Symptom
Heat will not
come on.

Cooling will not
come on.

System indicator
(flame: heat,
snowflake: cool)
is displayed, but
no warm or cool
air is coming
from the
registers.

Possible Cause

Action

No power to the thermostat.

Thermostat minimum off time is
activated.

• Wait up to five minutes for the system to respond.
• Configure heating response.

System selection is set to Off or
Cool.

Set system selection to Heat or Auto.

No power to the thermostat.

Thermostat minimum off time is
activated.

• Wait up to five minutes for the system to respond.
• Configure cooling response.

System selection is set to Off or
Heat.

Set system selection to Cool or Auto.

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 is yet given.

Conventional heating equipment
Wait one minute after seeing the on indicator and then check
turns the fan on only after the
the registers.
furnace has warmed to a setpoint.
Heating or cooling equipment is
not operating.

Verify operation of heating or cooling equipment in self-test.

Automation and Control Solutions
Honeywell International Inc.

Honeywell Limited-Honeywell Limitée

1985 Douglas Drive North

35 Dynamic Drive

Golden Valley, MN 55422

Toronto, Ontario M1V 4Z9

Source Exif Data:

File Type                       : PDF
File Type Extension             : pdf
MIME Type                       : application/pdf
PDF Version                     : 1.6
Linearized                      : Yes
Encryption                      : Standard V1.2 (40-bit)
User Access                     : Print, Copy, Fill forms, Extract, Assemble, Print high-res
Page Mode                       : UseOutlines
XMP Toolkit                     : 3.1-701
Producer                        : Acrobat Distiller 7.0 (Windows)
Creator Tool                    : FrameMaker 7.0
Modify Date                     : 2007:01:09 15:59:39-06:00
Create Date                     : 1999:07:07 12:30:47Z
Metadata Date                   : 2007:01:09 15:59:39-06:00
Format                          : application/pdf
Title                           : 62-0258 - T7351 Commercial Programmable Thermostat
Creator                         : Honeywell Technical Communications
Description                     : Installation Instructions
Document ID                     : uuid:c48d6373-18e8-4461-baf9-e833c47e6e08
Instance ID                     : uuid:d1b771f9-d295-4d96-82b9-ce6a391a68c3
Page Count                      : 12
Page Layout                     : SinglePage
Subject                         : Installation Instructions
Author                          : Honeywell Technical Communications

EXIF Metadata provided by EXIF.tools

Honeywell Thermostat T7351 Users Manual 62 0258 Commercial Programmable

Navigation menu

Versions of this User Manual:

Views

Navigation