T874G Thermostatsand Q674F,J Subbasesfor Heat Pump Systems

J.H. • Rev. 7-94 • • ©Honeywell Inc. 1994 • Form Number 69-0435—10

TRADELINE®
TABLE 1—THERMOSTAT/SUBBASE SPECIFICATIONS.

Application

The T874G Thermostats and Q674F,J Subbases pro-

vide 24 to 30 Vac control of 2-stage heating and 1-stage cool-

ing heat pump systems with automatic changeover. Stage 1

heat and cool anticipation is fixed voltage type; stage 2 heat

anticipation is adjustable (except as noted). See Table 1 for

specific T874G/Q674F,J combinations and specifications.

Installation Instructions for the Trained Service Technician.

Thermostat/
Subbase
Thermostat/
Subbase
Model LED Switching See
Package Numbers Indication System Fan Changeover Comments Fig.
Y594G1252 T874G1246/
Q674F1212 AUX.HT.,
EM.HT.
a
EM.HT.-OFF-
HEAT-AUTO-
COOL
AUTO-
ON AUTO,
COOL TRADELINE
®
5
—T874G1246/
Q674F1410 AUX.HT.,
EM.HT.
a
EM.HT.
b
-OFF-
HEAT-AUTO-
COOL
AUTO-
ON AUTO,
COOL Separate W1 and Y1
terminals; TRADELINE
®
subbase.
6
Y594G1419 T874G1642/
Q674F1444 AUX.HT.,
EM.HT.,
CHECK
OFF-EM.HT.-
HEAT-AUTO-
COOL
AUTO-
ON AUTO,
HEAT OR
COOL
SUPER TRADELINE
®
;
includes factory-installed
jumper across W1 and Y1;
fixed stage 2 heat anticipation.
7
Y594G1476
c
T874G1741/
Q674F1477
Isolated CHECK LED
includes jumper for connecting
X2 terminal to X or R for
power.
Y594G1534
d
T874G1824/
Q674F1477
Y594G1526 T874G1626/
Q674F1436 AUX.HT.,
EM.HT. OFF-EM.HT.-
HEAT-AUTO-
COOL
AUTO-
ON AUTO,
HEAT TRADELINE
®
8
—T874D1165
or
T874E1016/
Q674F1543
(RED)
e
OFF-EM.HT.-
HEAT-AUTO-
COOL
AUTO-
ON AUTO TRADELINE
®
subbase; exact
replacement for York model
no. 2TB04700524. Thermostat
not included; order separately.
9
Y594G1567 T874G1865/
Q674J1209 EM.HT. EM.HT.-
AUTO-OFF AUTO-
ON AUTO,
COOL TRADELINE
®
; exact
replacement for York model
nos. 2TH11702424 and
6TH11702424.
10
Y594G1575
c
T874G1873/
Q674J1225 EM.HT. EM.HT.-
AUTO-OFF AUTO-
ON AUTO,
COOL TRADELINE
®
; exact
replacement for York model
nos. 2TH11702424 and
6TH11702424.
10
Y594G1633 T874G1972/
Q674F1584 AUX.HT.,
EM.HT. OFF-EM.HT.-
HEAT-AUTO-
COOL
AUTO-
ON AUTO,
HEAT OR
COOL
TRADELINE
®
11
a EM.HT. also shows compressor malfunction.
b When switch is in EM. HT. position, the emergency heat will operate continuously until system switch is moved to another position.
c Thermostat is white and subbase is gray.
dSold only in Australia; degrees C.
e LED indicator is not labeled but may be connected per user's requirements. See Fig. 9.
M3375