Honeywell Heat/1Cool - T841A1563 Premier 2 Stage Thermostat User Manual page 45

Existing
Function Terminals
Common
Power
1st Stage Cool
1st Stage Heat
2nd Stage Heat
Fan
C/O Valve
Cool
C/O Valve
Heat
Em. Heat
Common 1st Stage
Compressor
System Monitor/
System Defrost
LED Indication
2nd Stage Cool
Terminal must be connected to the transformer common.
For auxiliary heat LED indication, jumper X2 to W2 on Q674. For emergency
heat LED indication, jumper X2 to E.
Relay required (R8222B1067 typically) for T8511M, T8611M,
PC8900/W8900B1002 application. See page 9 for wiring diagram.
TYPICAL THERMOSTATS AND SUBBASES — HONEYWELL MODEL NUMBER (CUSTOMER PART NUMBER)
Electromechanical
C X1
R R
Y1 Y1
W1 W1
W2 W2
G G
– O
– B
E E
– –
– –
X X2
Y2 Y2
T874D1074/Q674F1030 (HHO7AT172/HH93AZ174)
T874D1074/Q674F1063 (HH07AT172/HH93AZ181)
Electronic Replacement or Upgrade
Chronotherm ® III
C C
R R
W2 Y2
G G
O O/B
B O/B
E E
Y Y1
L L
X1 X2 –
Y2 Y2
Optional LED indication activated with completed circuit on X1 and
X2 terminals.
Configure O/B (select models) in Installer Setup.
Configure Y1/W1 terminal in installer setup.
L terminal is continuously energized in Em. Heat Mode.
LED is energized when terminal is powered.
CARRIER
TYPICAL 38BQ
Chronotherm IV
C C
R R
Y2 W2
G G
O/B O/B
O/B O/B
E E
Y1 Y1/W1
L L
X1 X2 –
Y2 Y2
M13148
70-6627 • 43