Fig. 4—T8631A 1-stage oil heat/1-stage cool. Oil Primary has its own transformer.

Fig. 5—T8631R 2-stage heat/1-stage cool thermostat with EM. HT.-HEAT-OFF-COOL system and ON-AUTO

fan switching.

3 69-0689—2
W2
AUTO
ON
FAN
SWITCH
O
W1
CHANGEOVER
RELAY (COOL)
C
MONITOR
G
FAN RELAY
SYSTEM
SWITCH
R
CHANGEOVER
RELAY (HEAT)
L2
L1
(HOT)
POWER
SUPPLY
SUBBASE
LOGIC/
CONTROL
CIRCUIT
STAT
LOGIC
CIRCUIT
2
BUS IN
POWER
SUPPLY
TRANS-
CEIVER
BUS OUT
BUS
POWER
SUPPLY
+
_
13.7 VDC
H2
H1
H3
H3
H4
H4 4
Y1
COOL
HEAT
OFF
HEAT/
COOL 1
B
AUXILIARY
HEAT RELAY
EMERGENCY
HEAT RELAY
STAGE 1
HEAT RELAY
COMPRESSOR
CONTACTOR
E
HIGH
LIMIT
L
E. HEAT
HIGH
LIMIT
TRANSFORMER
E. HEAT
RED
AUX.
HEAT
GREEN
HEAT 2
M3065A
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS
REQUIRED.
REMOVE JUMPER ( IF PRESENT) FOR SYSTEM WITH ISOLATED STAGE 1 HEATING
AND COOLING CONNECTIONS.
DENOTES THERMOSTAT TO SUBBASE INTERCONNECT.
DO NOT CONNECT H BUS WIRES TO THERMOSTAT UNTIL OTHER TotalHome
DEVICES ARE CONNECTED.
1
4
2
3
1
3
RW
COOLING
DAMPER/
COOLING
CHANGE-
OVER
RELAY
Y
AIR
COND.
EQUIP.
O G
FAN
RELAY
C B
HEATING
DAMPER/
HEATING
CHANGE-
OVER
L1
(HOT)
L2
1
1
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
1M3089
HEATING-COOLING WALLPLATE
L1
(HOT)
L2
T
OIL PRIMARY
T