Honeywell MULTISTAGETHERMOSTATSAND T874H - Manual (Page 4)

69-0087—6 4
T874H,Q,W MULTISTAGE THERMOSTATS AND Q674B,C,G,L SUBBASES
L2
1 OFF
H1 ANTICIPATOR
H2 ANTICIPATOR
H1
1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND
OVERLOAD PROTECTION AS REQUIRED.
M6008A
Y1
W1
C1 ANTICIPATOR
AUTO
FALL
FALL
CHANGEOVER
RELAY
L1
(HOT)
R
FAN RELAY
COMPRESSOR
CONTACTOR
G
3
THERMOSTAT SUBBASE SYSTEM COMPONENTS
NO FAN
SWITCH
SYSTEM
SWITCH
RISE
H2
W2
B
1
4
6
8
9
10
C1
L1 (HOT)
L2
1
W1
T
W2
HEAT RELAY 3
FAN RELAY
W3
HEAT CHANGEOVER VALVE
COMPRESSOR CONTACTOR 2
B
Y2
Y1
SYSTEM
SWITCH
HEAT
OFF
COOL
H1 ANTICIPATOR
C1
H1 FALL
H3
1 POWER SUPPLY. PROVIDE DISCONNECT
MEANS AND OVERLOAD PROTECTION
AS REQUIRED.
M3674
AUTO
ON
FAN SWITCH
FALL
R
COMPRESSOR CONTACTOR 1
HEAT RELAY 2
HEAT RELAY 1
G
C815A THERMISTOR
H2 ANTICIPATOR
FALL
H3 ANTICIPATOR
H2
C2 ANTICIPATOR
C2
RISE
RISE
COOL CHANGEOVER VALVE
O
C1 ANTICIPATOR
RESET HEATER
THERMOSTAT SUBBASE SYSTEM COMPONENTS
1
2
3
4
5
6
8
10
11
Fig. 6. T874Q/Q674G for heating only system.
Fig. 7. T874W/Q674B with outdoor reset in heating and cooling system.