Standard Models - Honeywell T874 Product Data

Standard Models

T874 THERMOSTATS
Models: See Table 3.
Electrical Rating: 24 to 30 Vac.
Switching: Coiled bimetal elements operate mercury
switches.
Temperature Adjustment: Heating and cooling setting
levers, with separate scales located on top of thermostat
base. Common lever for heating and cooling on T874R;
one cooling lever on T874E,V; and one heating lever on
T874F,Q.
Dimensions: See Fig. 1.
Temperature: Scale Range: 42° to 88°F (6° to 31°C) stan-
dard; optional ranges available.
THERMOSTAT MOUNTED
ON SUBBASE
FRONT
5-5/8 (143)
50 60 70 80
HEAT
50 60 70 80
FAN
AUTO ON OFF EM. HT. HEAT AUTO COOL
Optional Specifications (T874 Only):
Temperature scale ranges are 40° to 75°F (4° to 24°C) heat-
ing and 75° to 90°F (24° to 32°C) cooling with stop; 44° to
68°F (7° to 20°C) heating, 80° to 86°F (27° to 30°C) cool-
ing; 6° to 29°C (43° to 85°F) Celsius scale; 3° to 22°C (38°
to 72°F) and 26° to 32°C (78° to 90°F) cooling with stop.
Nonadjustable factory-added stop limits heating setpoint to
72°F (22°C) maximum and cooling setpoint to 78°F (26°C)
minimum.
OEM customer personalization.
Locking cover and locking lever (see Thermostat Accesso-
ries).
Thermostat cover without thermometer.
Adjustable locking temperature stops.
Voltage heat anticipation for first or second stage heat or both.
See Table 3.
Fast cycling on heating stage(s) for electric heat applications.
C815A Outdoor Thermistor for improved performance on
specified models.
3/8 (10)
50 60 70 80
COOL
1-7/8 (48)
2-3/16 (56)
Fig. 1. T874 Thermostat and Q674 Subbase dimensions in in. (mm).
T874 MULTISTAGE THERMOSTATS AND Q674 SUBBASES
Thermometer Range: 42° to 88°F (6 to 31°C)
Changeover Differential: 4°F (2°C) minimum between heat-
ing and cooling (5°F [3°C] on T874W). Levers can be set
apart for greater separation.
Interstage Differential:
Standard Models: Mechanical differential is 1°F (0.6°C)
between heating or cooling stages; operating differential is
approximately 1.9°F (1°C) between stages in heating or
cooling.
Special Models: See Table 3.
Finish: Beige or Premier White
Mounting Means: T874 Multistage Thermostat mounts on
Q674 Subbase. Subbase mounts horizontally on wall or
outlet box. Mounts on vertical outlet box with optional
193121A Adapter Plate Assembly.
SIDE
1-1/2
(38)
3-1/2
(89)
FAN
Thermostat Accessories:
Locking Cover and Locking Lever Assembly: Part no.
194559R with thermometer; 194559S without thermome-
ter. See Fig. 2. Includes cover, screws, and Allen wrench
for locking cover. The screws must be used to assure
proper operation.
Adjustable Lever Stop: Part no. 4074ECK; includes lever stop
and screws.
Universal Versaguard™ Thermostat Guard: Includes wall-
plate, ring base, guard cover, tumbler lock, two keys and
optional Honeywell logo insert. Double-wall construction
provides extra measure of tamper-resistance. Tamper-
resistant lock; key cannot be removed without being in
locked position. Vents in guard base allow airflow for opti-
mum thermostat performance. See form 68-0104 for more
information.
— TG511A1000: Clear cover.
— TG511B1008: Opaque cover.
— TG511D1004: Painted steel (off-white) cover. See
Fig. 2.
3
®
finish.
SUBBASE
3-9/32 (83)
AUTO ON OFF EM. HT. HEAT AUTO COOL
5-1/8 (130)
3-7/16
(87)
M5849
60-2485—8