Honeywell T8090A User Manual

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69-0750—1
L1 
(HOT)
L2
1
1
L1 
(HOT)
L2
1
HEAT
RELAY
COMPRESSOR
CONTACTOR
CLOCK
POWER SUPPLY.  PROVIDE DISCONNECT MEANS AND 
OVERLOAD PROTECTION AS REQUIRED.
JUMPER RH-RC TERMINALS WHEN ONE TRANSFORMER 
POWERS BOTH HEATING AND COOLING.
FOR POWER STEALING ON HEATING, JUMPER 
C-RC AND C-Y TERMINALS.
2
3
3
2
THERMOSTAT
BATTERY
SUBBASE
C
C
RH
RC
W
Y
M720A
Fig. 19—Typical hookup for clock powered through control system. Clock powered by battery when
heating or cooling equipment is on; clock takes power from system when cooling equipment is off.
Fig. 20—Internal schematic and typical hookup for T8090A Thermostat/191108AJ Wallplate in heating-
only system.
H
FALL
C
L1 
(HOT)
L2
1
2
2
1
2
H
FALL
C
POWER SUPPLY.  PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
FOR STEAM SYSTEM, KEEP JUMPER IN PLACE. FOR NON STEAM SYSTEM, CUT AND 
TAPE-OFF THE JUMPER AND ADJUST HEAT ANTICIPATOR FOR PROPER EQUIPMENT CYCLING.
HEAT
ANTICIPATOR
HEAT
ANTICIPATOR
C
C
R
W
HEAT
RELAY
CLOCK
THERMOSTAT
WALLPLATE
M5349A