Bryant DUAL FUEL THERMOSTAT TSTAT User Manual

Page 3

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TABLE 1—HEATING STAGES

WIRING

DIAGRAM

SYSTEM

TYPE

OUTDOOR TEMP/

BAL. PT. TEMP

STAGE 1

STAGE 2

STAGE 3

Fig. 2

1-speed HP

1-stage furnace

Above

HP

Furnace

Below

Furnace

Fig. 3

1-speed HP

2-stage furnace

Above

HP

Furnace Lo

Furnace Hi

Below

Furnace Lo

Furnace Hi

Fig. 4

2-speed HP

1-stage furnace

Above

HP Lo

HP Hi

Furnace

Below

Furnace

Fig. 5

2-speed HP

2-stage furnace

Above

HP Lo

HP Hi

Furnace Lo or Hi

Below

Furnace Lo or Hi

I.

THERMOSTAT LOCATION

Thermostat should be mounted:

Approximately 5 ft (1.5m) from floor.

Close to or in a frequently used room, preferably on an inside
partitioning wall.

On a section of wall without pipes or duct work.

In a location where the outdoor temperature sensor wires can be
routed to thermostat location. It is acceptable to use 2 separate
wires in thermostat cable to connect outdoor sensor. These
wires may be connected at furnace to another pair continuing to
outdoor heat pump. The outdoor sensor may then be mounted
and connected in vicinity of heat pump, but be sure it is not
located in direct sunlight.

Thermostat should NOT be mounted:

Close to a window, on an outside wall, or next to a door leading
to the outside.

Exposed to direct light and heat from a lamp, sun, fireplace, or
other temperature-radiating object which may cause a false
reading.

Close to or in direct airflow from supply registers and return-air
grilles.

In areas with poor air circulation, such as behind a door or in
an alcove.

II.

SET DIP SWITCHES

There are 4 small switches on the back of the circuit board which
must be set by the installer. The ON position is indicated by small
letters on the switch itself. Ignore numbers 1-4 on the switch. The
switch designation (A through D) is on the circuit board next to the
switch. To change a switch position use the corner of a small
screwdriver to slide it between on and off. Make these selections
BEFORE installing the thermostat--it is much easier.

SWITCH A—NOT USED IN DUAL FUEL THERMOSTATS

This switch must be in OFF position in all dual fuel applications.
DO NOT turn ON.

SWITCH B—SETBACK RECOVERY

Selects between normal and smart recovery from setback. Normal
recovery changes to the new setpoint at the programmed time.
Smart recovery, which is active in heating mode only, starts earlier
and adjusts the setpoint slowly so that room temperature will arrive
at the programmed temperature at the programmed time.
TO SET:
OFF—for smart recovery. This is the factory default.
ON—for normal recovery.

SWITCH C—DISABLE LOW-AMBIENT COOLING

Use to allow or prevent cooling operation below an outdoor
temperature of 55˚F. Prevention of cooling below 55˚F adds to
compressor reliability. If outdoor temperature sensor fails or is
disconnected, cooling is allowed regardless of switch setting.
TO SET:
OFF—cooling is allowed at outdoor temperatures below 55˚F.
ON—cooling is disabled at outdoor temperatures below 55˚F.

SWITCH D—SELECT SINGLE-SPEED OR 2-SPEED HP

Use this switch to tell dual fuel thermostat whether it is controlling
a single- or 2-speed HP. It must be set properly.
TO SET:
OFF—for single-speed HP.
ON—for 2-speed HP.

III.

INSTALL THERMOSTAT

WARNING:

Before installing thermostat, turn off all

power to unit. There may be more than 1 power discon-
nect. Electrical shock can cause personal injury or death.

1. Turn OFF all power to unit.

2. If an existing thermostat is being replaced:

a. Remove existing thermostat from wall.

b. Disconnect wires from existing thermostat, 1 at a time.

Be careful not to allow wires to fall back into the wall.

c. As each wire is disconnected, record wire color and

terminal marking.

d. Discard or recycle old thermostat.

NOTE:

Mercury is a hazardous waste and MUST be disposed of

properly.

3. Open thermostat rear door (mounting base) to expose

mounting holes. The base can be removed to simplify
mounting. Snap apart carefully at hinge to separate mount-
ing base from remainder of thermostat.

4. Route thermostat wires through large hole in mounting

base. Allow an extra 10 to 12 in. of wire for connection to
terminals. Remove outer sheath over this entire length for
added flexibility.

5. Level mounting base against wall and mark wall through 2

mounting holes.

6. Drill two 3/16-in. mounting holes in wall where marked.

7. Secure mounting base to wall with 2 screws and anchors

provided, making sure all wires extend through mounting
base.

8. Adjust wire length and routing to allow proper closure of

thermostat. Strip each wire end no more than 1/4 in. to
prevent adjacent wires from shorting together. Match and
connect equipment lead wires to the correct terminals of the
thermostat connector. (See Fig. 2 through 5.) Both R and C
must be connected for proper thermostat operation.

CAUTION:

Improper wiring or installation may damage

the thermostat. Check to make sure wiring is correct
before proceeding with installation or turning on unit.

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