T874 Multistage Thermostats And Q674 Subbases; Optional Specifications (Q674 Only); Heating, Cooling Levers And System Led Indicators - Honeywell T874 Product Data

T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES

Q674E—Standard and TRADELINE.
Q674F—Two LED models.
— EM.HT. light.
— Provision for AUTO fan operation in
EM.HT.
Q674G—O and B terminals.
Q674J—Provision for AUTO fan operation
in EM.HT.
— Provision for outdoor thermistor.
Q674K—Standard.
Q674L—Provision for AUTO fan operation in
EM.HT.
— Indicator LEDs.
Q674N—Standard.
Q674P—Standard.
Q674Q—Standard.
Q674R—Standard.
— International symbols.
Q674S—Indicator LED.

Optional Specifications (Q674 Only):

Models available with up to four LEDs; for example, LEDs can
show EM. HT, AUX. HT, SERVICE, CHECK, FILTER, and
LOCKOUT. See Fig. 3.
System switching marked HEAT-OFF/RESET-COOL for sys-
tems requiring impedance relay reset. Available on Q674B
only.
G terminal isolated on heating to provide fan relay operation
from external low voltage fan switch (Q674B only).
Auto fan operation on both heat and cool.
T874 Thermostat with
One Setpoint Lever
60-2485—8
Q672E
Q672F
Q672G
Q672J
Q672K
Q672L
Q672N
Q672P
None
None
None
T874 Thermostat with
Heating and Cooling Levers
Fig. 3. Heating, cooling levers and system LED indicators.
Standard OFF-HEAT-AUTO-
COOL
Heat Pump OFF-EM.HT.-HEAT-
AUTO-COOL
OFF-COOL-AUTO-
HEAT-EM.HT.
Standard OFF-AUTO
Heat Pump EM.HT.-AUTO-OFF
EM.HT.-ON-OFF
SUPL.HT.-ON-OFF
Standard OFF-HEAT-AUTO-
COOL
OFF-WOOD-WOOD/
OIL-OIL
Heat Pump EM.HT.-HEAT-OFF-
COOL
SUPL.HT.-HEAT-
OFF-COOL
Evaporative EVAP-COOL-OFF-
Cooler HEAT
Heat Pump SUPL.HT.-HEAT-
COOL
Fan Coil HEAT-OFF-COOL
Fan Coil OFF-COOL
Standard HEAT-COOL
L terminal is used for system monitoring devices.
Common R terminal for heating/cooling.
Changeover in cool or heat mode for heat pumps.
Auto fan in EM.HT. for heat pumps.
Subbase Accessory: 193121A Adapter Plate Assembly for
mounting on vertical outlet box. Assembly includes adapter
ring and cover plate. Use to cover wall marks from
replaced thermostat.
Separate
6
AUTO-ON T874A-D
AUTO-ON T874C,D,G,N,S
AUTO-ON
None T874A-F
AUTO-ON T874A,D,G,J
AUTO-ON
AUTO-ON
None T874F
None
AUTO-ON T874R,W
AUTO-ON
AUTO-ON T874C
AUTO-ON T874G
LO-MED-HI- T874A
ON
LO-HI- T874V
CONT.
None T874C
Q674 Subbase
with Four LEDs