Honeywell T8400C Installation Instructions - Page 3

Operation - manual

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T8400C AND T8401C ELECTRONIC THERMOSTATS KEEP WIRING IN SHADED AREA ALTERNATE MOUNTING SCREW HOLE W Y G R C MOUNTING SCREW HOLE ALTERNATE MOUNTING SCREW HOLE WIRING ENTRANCE HOLE MOUNTING SCREW HOLE M11023 Fig. 3. Restrict wiring to shaded area. W Y T8400C, T8401C W Y G R 2C 1 L1 (HOT) 24V L2 COOLING CONTACTOR 1 L1 (HOT) L2 FAN RELAY T T OIL PRIMARY CONTROL 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 IN T8401C INSTALLATIONS, CONNECT C TERMINAL. M11022B Fig. 6. T8400C/T8401C heat-cool wiring diagram in oil heating/electric cooling system. Oil primary has its own transformer. Mounting Thermostat to Wallplate 1. Engage the tabs at the top of the thermostat and wallplate. 2. Swing down the thermostat and press the lower edge of the thermostat onto the wallplate to latch. See Fig. 7. DASHED LINES INDICATE TABS ON BACK OF THERMOSTAT G FOR WRAPAROUND STRIP 7/16 IN. (11 MM) R FOR STRAIGHT INSERTION STRIP 5/16 IN. (8 MM) C TERMINAL SCREW Fig. 4. Wiring connections. M11232 T8400C, T8401C W Y G R 2C 1 L1 (HOT) 24V L2 COOLING CONTACTOR HEATING PRIMARY CONTROL FAN RELAY 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED. 2 IN T8401C INSTALLATIONS, CONNECT C TERMINAL. M11021B Fig. 5. T8400C/T8401C heat-cool wiring diagram in single transformer system with gas heat/electric cooling. Set Room Set Room FAN Auto On SYSTEM Cool Off Heat FAN Auto SYSTEM Cool Off Heat A ENGAGE TABS AT TOP OF THERMOSTAT WITH SLOTS ON WALLPLATE. M18416 B PRESS LOWER EDGE OF CASE TO LATCH. Fig. 7. Mounting thermostat wallplate. OPERATION Setting FAN and SYSTEM Switches Fan and system settings are controlled manually by using the switches located at the bottom of the thermostat case. See Fig. 8. FAN Switch Fan switch settings are: On: The fan runs continuously. Use for improved air circulation and air quality. Auto: Normal setting for most homes. In cooling, the fan starts and stops with the cooling equipment. In heating, the fan is controlled directly by the heating equipment and may start a few minutes after the heating equipment turns on (on most systems). When using an electric heat thermostat, the fan starts and stops with the heating equipment. 3 69-1480-1

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T8400C AND T8401C ELECTRONIC THERMOSTATS
3
69-1480-1
Fig. 3. Restrict wiring to shaded area.
Fig. 4. Wiring connections.
Fig. 5. T8400C/T8401C heat-cool wiring diagram in
single transformer system with gas heat/electric
cooling.
Fig. 6. T8400C/T8401C heat-cool wiring
diagram in oil heating/electric cooling system.
Oil primary has its own transformer.
Mounting Thermostat to Wallplate
1.
Engage the tabs at the top of the thermostat and
wallplate.
2.
Swing down the thermostat and press the lower
edge of the thermostat onto the wallplate to latch.
See Fig. 7.
Fig. 7. Mounting thermostat wallplate.
OPERATION
Setting FAN and SYSTEM Switches
Fan and system settings are controlled manually by
using the switches located at the bottom of the
thermostat case. See Fig. 8.
FAN Switch
Fan switch settings are:
On: The fan runs continuously. Use for improved air
circulation and air quality.
Auto: Normal setting for most homes. In cooling, the
fan starts and stops with the cooling equipment. In
heating, the fan is controlled directly by the heating
equipment and may start a few minutes after the
heating equipment turns on (on most systems).
When using an electric heat thermostat, the fan
starts and stops with the heating equipment.
M11023
ALTERNATE
MOUNTING
SCREW HOLE
MOUNTING
SCREW
HOLE
MOUNTING
SCREW HOLE
ALTERNATE MOUNTING
SCREW HOLE
KEEP WIRING IN
SHADED AREA
WIRING ENTRANCE HOLE
W
Y
G
R
C
M11232
FOR WRAPAROUND
STRIP 7/16 IN. (11 MM)
FOR STRAIGHT INSERTION
STRIP 5/16 IN. (8 MM)
TERMINAL SCREW
W
G
Y
R
C
L1
(HOT)
L2
1
2
1
2
W
Y
G
R
C
COOLING
CONTACTOR
FAN
RELAY
HEATING
PRIMARY
CONTROL
24V
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
IN T8401C INSTALLATIONS, CONNECT C TERMINAL.
M11021B
T8400C, T8401C
L1
(HOT)
L1
(HOT)
L2
L2
1
1
2
1
W
Y
G
R
C
2
COOLING
CONTACTOR
FAN
RELAY
OIL PRIMARY
CONTROL
T
T
24V
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
IN T8401C INSTALLATIONS, CONNECT C TERMINAL.
M11022B
T8400C, T8401C
M18416
FAN
SYSTEM
Auto On
Cool Off Heat
DASHED LINES INDICATE TABS
ON BACK OF THERMOSTAT
FAN
SYSTEM
Auto
Cool Off Heat
ENGAGE TABS AT TOP
OF THERMOSTAT WITH
SLOTS ON WALLPLATE.
A
B
PRESS LOWER EDGE OF
CASE TO LATCH.
Set
Room
Set
Room