Honeywell Heat/1Cool - T841A1563 Premier 2 Stage Thermostat User Manual page 49

Existing
Function
Terminals
Common
X
Power
R
Compressor
Y
1st Stg. Heat
–
Aux. Heat
W2
Fan
G
C/O Valve
B
Heat
C/O Valve
O
Cool
System Monitor/
L
System Defrost
EM. Heat
E
Multiple Aux.
W3
Heat Loads
LED Indication
–
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 loads such as contactors, sequencers,
or relays.
Terminal X (C) must be connected to transformer common.
Do not remove factory-installed jumper.
LED is energized when terminal is powered.
Electromechanical
X X X
R R R
Y 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
– – –
TYPICAL THERMOSTATS AND SUBBASES — HONEYWELL MODEL NUMBER
T874G1915/Q674F1212
Electronic Replacement or Upgrade
Chronotherm ®
III
C C
R R
or
Y1 Y Y
W1 W1
W2 W2
G G
B B
O O
L L
E E
X1 X2 –
– –
Field-installed X2 to X jumper (provided).
Optional CHECK LED on T8611G1004. See Fig. 26.
Optional LED indication activated with completed circuit on X1 and X2
terminals.
If multiple auxiliary heat loads are used, connect to W2 (Aux W8900B)
terminal.
L terminal is powered continuously when thermostat is in Em. Ht. position.
T874R1921/Q674L1207
ECONAR
Chronotherm
IV
C C C
R R R
Y1 Y Y1
W1 W1 W1
W2 W2 W2
G G G
or or
B O/B B B O/B
or or
O O/B O O O/B
L L L
E E E
– – X1 X2
– – –
70-6627 • 47
C
R
Y1/W1
–
Aux.
G
O/B
O/B
L
E
–
W2
M13152