Q674 Subbase Specifications - Honeywell T874 Product Data

— Fast cycling.
T874G—Heat pump, cool
changeover, with fast cycling.
— Fixed anticipator for H2.
— Fast cycling.
T874H—Use with Q674C.
T874J—Heat pump.
T874K—Heat pump.
T874L—Heat pump.
T874N—Heat pump, heat
changeover.
T874P—Heat pump.
T874Q—Night setback heating.
T874R—Heat pump.
T874S—Two-speed compressor heat
pump.
T874V—Standard.
T874W—Heat pump and standard.
— Night setback heating.
a
Department of Defense.
b
Changeover stage operates with heating.
c
Fixed voltage type anticipation.
d
Changeover stage operates with heating; a secondary changeover is provided in cooling switch.
e
Provides night setback used with standard T874 and timer-operated remote switching.
f
Manual changeover stage—use Q674B,L subbase.
g
Changeover stage operates with cooling.
Models:
See Table 4.
Electrical Ratings:
Switch Contacts: 2.5A at 30 Vac (7.5A inrush).
LED Lights (Optional): 30 Vac.
Switches: Two slide switches (one switch on Q674G and K;
no switches on Q674D) operated by levers. Switch position
is shown on scaleplate.
Models and Options
Q674A—Standard and TRADELINE®.
— Indicator LEDs.
Q674B—Standard and TRADELINE.
— Provision for fan relay operation from
external fan switch (isolate G terminal).
— Indicator LEDs.
Q674C—Standard and TRADELINE.
— Indicator LEDs.
Q674D—Standard and TRADELINE.
— For use when subbase switching is not
required.
Electric Heat
T872G Heat Pump or
Standard
T872H Heat Pump or
Standard
None Heat Pump
None Heat Pump
None Heat Pump
T872N Heat Pump
None Heat Pump
T872Q Standard
T872R
f
Heat Pump
None Heat Pump
None Standard
T872W Heat Pump or
Standard
Q674 Subbases
Table 4. Q674 Subbase Specifications.
Replaces Application
Q672A Standard
Q672B Standard
Heat Pump
Q672C Standard
Heat Pump
Q672D Standard
5
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
0.12-
0.6A
2 1 b
1 0-1.0A
1 1 b
1 0-1.0A
2 1
d
2 0-1.0A
2 1 0.1-1.2A 0-1.5A
b
1
2 1 — 0.1-1.2A 0.1-1.2A 0-1.5A
2 1 0.1-1.2A 0.1-1.2A 0-1.0A
b
1
2 1 — 0.1-1.2A 0.1-1.2A 0-1.5A
e — — 0.1-1.2A
1
2 1 —
0-1.5A
2 2
g
1 0-1.2A
— 1 —
3 2 —
0-1.2A
Mounting: Designed to mount horizontally on an outlet box
or the wall. Adapter plate assembly available for mounting
on a vertical outlet box (see Subbase Accessory).
Finish: Dark brown or gray.
Dimensions in in. (mm): 3-1/2 (89)height; 5-5/8 (143) width;
5/16 (8) depth. See Fig. 1.
Switch Positions
System
HEAT-AUTO-COOL
HEAT-OFF-COOL
OVERRIDE-HEAT-
OFF-COOL
OFF-AUTO
OVERRIDE-AUTO-
OFF
None
0.12-
0.6A
c 0.1-1.2A 0-1.0A
0.1-1.5A
0.12-
0.6A
c — 0-1.0A
e c c
0-1.5A 0-1.0A
0-1.5A
c
— —
0.1-1.2A 0-1.5A
c
0-1.2A
c c
0-1.2A
— — 0-1.5A
0-1.2A
b c,d
0-1.2A
Fan Use With
AUTO-ON T874A-D
AUTO-ON T874A-D
T874G,H,L,R
AUTO-ON T874P
AUTO-ON T874A-H,W
AUTO-ON T874K,L,N
T874P
None T874A-F
60-2485—8
—
—
—
—
—
—
—
—
—
0-1.0A
—
0-1.0A