Applications; Modulating, Touch-Screen, Non-Communicating Thermostat ((-)Hc-Tst412Mdms) - Rheem RGFG Installation Instructions Manual

FURNACE OPERATION WITH A TWO-
STAGE THERMOSTAT
To set the furnace for operation with
two-stage non-communicating ther-
mostats, set switches 2 & 3 of SW2 to
the "ON" position (See Figure 41). Note
that these switches should be in the
"OFF" position from the factory. With
both switches in the "ON" position, the
THERMOSTAT APPLICATION GUIDE
furnace can still recognize a "V" signal
Description
Modulating PWM output, gas furnace
present and will still operate with a
Heat Pump (with Aux. or Emergency Heat), 2 Stage
modulating thermostat. However, with
Systems with up to 3 Stages Heat, 2 Stages Cool
both switches of SW2 in the "ON" posi-
Heat Only Systems
tion, the furnace is set to operate with a
Wired Remote Temperature Sensor (Indoor/Outdoor)
Dual Fuel Feature (Heat Pump Mode)
two-stage thermostat as well.
With a two-stage non-communicating
thermostat (installed as shown in Figure
60) and switch settings configured as
described above, during a call for heat,
the furnace will operate as follows:
First Stage
("W"=ON and "W2"=OFF)
40% of furnace capacity always
Second Stage
("W"=ON and "W2"=ON)
Phase 1: 0 to 5 minutes = 65% of fur-
nace capacity
Phase 2: After 5 minutes = 100% of
furnace capacity
NOTE: If the call for heat ends during
any phase and/or stage, the furnace
will terminate immediately at the firing
rate of that phase and/or stage.

APPLICATIONS

MODULATING TOUCH-
SCREEN NON-COMMUNI-
CATING THERMOSTAT
24 VOLT CONTROL
INSTALLATION
WARNING
THERMOSTAT INSTALLATION AND
ALL COMPONENTS OF THE CON-
TROL SYSTEM SHALL CONFORM TO
CLASS II CIRCUITS PER THE NEC
CODE.
FIGURE 59
(-)HC-TST412MDMS BASE
+
Mounting
S
-
Y2
Hole
W2
W/E
V
Place Level
across
Mounting Tabs
(for appearance only) (for appearance only)
Rear view of thermostat
96
Model
(-)HC-TST412MDMS
THERMOSTAT APPLICATION GUIDE
Description
Modulating PWM output, gas furnace
Heat Pump (with Aux. or Emergency Heat), 2 Stage
Systems with up to 3 Stages Heat, 2 Stages Cool
Heat Only Systems
Wired Remote Temperature Sensor (Indoor/Outdoor)
Yes
Dual Fuel Feature (Heat Pump Mode)
Yes
Yes For complete product specifications, see
Yes
the Installation Instructions supplied with
Yes
thermostat.
Yes
FIGURE 56
(-)HC-TST412MDMS
MODULATING TOUCHSCREEN THERMOSTAT
REMOVE OLD THERMOSTAT
A standard heat/cool thermostat con-
sists of three basic parts:
1. The cover, which may be either a
snap-on or hinge type.
2. The base, which is removed by loos-
ening all captive screws.
3. The switching subbase, which is
removed by unscrewing the mounting
screws that hold it on the wall or
adapter plate. Before removing
wires from old thermostat, label
each wire with the terminal desig-
nation from which it was attached.
Disconnect the wires from the old
thermostat one at a time. Do not let
wires fall back into the wall.
INSTALLING NEW THERMOSTAT
1. Pull the thermostat body off the ther-
mostat base. Forcing or prying on the
TERMINAL DESIGNATION DESCRIPTIONS
Terminal Designation
Mounting
B . . . . . . . . . . . . . . . . . . Changeover valve for heat pump energized constantly in heating
Hole
O . . . . . . . . . . . . . . . . . . Changeover valve for heat pump energized constantly in cooling
Place Level Y2 . . . . . . . . . . . . . . . . . . 2nd Stage Compressor
across
Y . . . . . . . . . . . . . . . . . . Compressor Relay
Mounting Tabs
G . . . . . . . . . . . . . . . . . . Fan Relay
RC . . . . . . . . . . . . . . . . . . Power for Cooling
RH . . . . . . . . . . . . . . . . . . Power for Heating
2 "AA" Batteries
C . . . . . . . . . . . . . . . . . . Common wire from secondary side of cooling
V . . . . . . . . . . . . . . . . . . PWM Output
W/E . . . . . . . . . . . . . . . . . Heat Relay/Emergency Heat Relay (Stage 1)
W2 . . . . . . . . . . . . . . . . . . 2nd Stage Heat (3rd Stage Heat in HP2)
- . . . . . . . . . . . . . . . . . . . Common (DC) for wired remote temperature sensor
S . . . . . . . . . . . . . . . . . . Frequency signal from remote temperature sensor
+ . . . . . . . . . . . . . . . . . . Power (DC) to remote temperature sensor
2
Programming Choices
Non-Programmable 5/1/1 Day 7 Day
Yes
Yes
Yes
Yes
Yes
Yes
Description
Model Programming Choices
Non-Programmable 5/1/1 Day
(-)HC-TST401MDMS
thermostat will cause damage to
the unit. Rear view of thermostat
2. Place base over hole in wall and
mark mounting hole locations on
wall using base as a template.
3. Move base out of the way. Drill
mounting holes. If you are using
existing mounting holes and the
holes drilled are too large and do
not allow you to tighten base
snugly, use plastic screw anchors
to secure the base.
4. Fasten base snugly to wall using
mounting holes shown in Figure
59 and two mounting screws.
Leveling is for appearance only
and will not affect thermostat oper-
ation.
5. Connect wires to terminal block on
base using appropriate wiring
schematic (see Figures 53 through
55).
6. Push excess wire into wall and
plug hole with a fire resistant
Mounting
material (such as fiberglass insula-
Hole
tion) to prevent drafts from affect-
ing thermostat operation.
Place Level
7. Carefully line the thermostat up across
Mounting Tabs
with the base and snap into place.
(for appearance only)
BATTERY LOCATION
2 "AA" alkaline batteries are includ-
ed in the thermostat at the factory
with a battery tag to prevent power
drainage. Remove the battery tag to
engage the batteries. To replace
batteries, set system to OFF,
remove thermostat from wall and
install the batteries in the rear along
the top of the thermostat (see Figure
59).
WIRING CONNECTIONS
Refer to equipment manufacturers'
instructions for specific system wiring
information. After wiring, see CON-
FIGURATION section for proper ther-
mostat configuration. For wiring dia-
grams, see Figures 53 through 55.
Wiring diagrams shown are for typi-
cal systes and describe the thermo-
stat terminal functions.
7 Day
+
S
-
Y2
W2
W/E
V
(for
Rear view of thermostat