Honeywell Heat/1Cool - T841A1563 Premier 2 Stage Thermostat User Manual page 43

Existing
Function
Terminals
C1
Common or C
X1
Power
R
Compressor W1 or Y
1st Stg. Heat –
Aux. Heat
W2
Fan G
C/O Valve B
Heat
C/O Valve Y1 or O
Cool
System Monitor/
L or F
System Defrost
EM. Heat
X or E
Multiple Aux. W3
Heat Loads
Defrost
P
LED Indication X
2nd Stage
–
Compressor
Configure O/B (select models) in Installer Setup.
When W2 is not used, configure W2 cycle rate to NC.
If provided on original equipment.
Terminal is for multiple second stage heating loads such as contactors,
sequencers, or relays.
Model 545 typical. P terminal provided on T8611R1000 only.
Terminal X (C, X1, C1) must be connected to transformer common.
Do not remove factory-installed jumper.
TYPICAL THERMOSTATS AND SUBBASES — HONEYWELL MODEL NUMBER (CUSTOMER PART NUMBER)
T872G1166/Q672F1125
T872G1174/Q672F1125
T874G1261/Q674F1253
T874G1451 (HH641502)/Q674F1212
Electromechanical
X X X
R R R
Y1 Y Y1
– W1 W1
W2 W2 W2
G G G
B B B
O O O
L
E E E
W3 W3 W3
– – –
– X2 X1 X2
– – –
T874J1010/Q674J1084 (34427DP124/P272-2471/34427DP126,P272-1879)
T874J1010/Q674L1371 (34427DP124/P272-2471/34427DP125,P272-1878)
T874R1004/Q674B1042
T874R1335 (HH641501)/Q674L1405
B.D.P. (BRYANT-DAY/NIGHT-PAYNE)
Electronic Replacement or Upgrade
Chronotherm ®
III
C C
R R
or
Y1 Y Y
W1 W1
W2 W2
G G
B B B or O/B
O O O
L L
E E
P –
X1 X2 –
– –
Optional CHECK LED on T8611G1004. See Fig. 26.
Field-installed X2 to X jumper (provided).
If multiple auxiliary heat loads are used, connect to W2 (Aux W8900B)
terminal.
LED is energized when terminal is powered.
Optional Check LED activated with completed circuit on X1 and X2 terminals.
L terminal is powered continuously when thermostat is in Em. Ht. position.
Chronotherm
IV
C C C
R R R
Y1 Y Y1
W1 W1 W1
W2 W2 W2
G G G
B B or O/B
or or
O/B O O O/B
L L L
E E E
– – –
– – X1 X2
– – –
70-6627 • 41
C
R
Y1/W1
–
Aux.
G
O/B
O/B
L
E
–
–
W2
M13146