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S8XB-SVX001-1A-EN 43
TWINNING CONNECTION DIAGRAM
FOR TWINNING S-SERIES FURNACES
2 STAGE HEAT / 1 STAGE COOLING
(WITH TRANSFORMER) THERMOSTAT
2 STAGE HEATING
1 STAGE COOLING
THERMOSTAT
FURNACE NO. 1 FURNACE NO. 2
R2
R2
ISOLATION RELAY
(FIELD SUPPLIED)
ISOLATION RELAY
R1
R1
Y1
B
Y1 Y1 Y1
W1
W1
W1
W2 W2 W2
R R R
G G
G
B
B
B
NOTES:
1. BOTH FURNACES MUST BE POWERED FROM
THE SAME 115 VAC PHASE LEG AT THE CIRCUIT BREAKER.
2. TRANSFORMERS MUST BE IN PHASE.
- MEASURE THE VOLTAGE BETWEEN THE “R” TERMINALS
ON BOTH FURNACES, VOLTAGE SHOULD BE LESS THAN
10 VOLTS.
- IF GREATER, REVERSE THE LOW VOLTAGE ON ONE OF THE
TRANSFORMERS AND RECHECK.
3. HEATING AND COOLING AIRFLOW MUST BE THE SAME FOR
BOTH FURNACES.
4. OD UNIT TYPE SETUP MUST BE SET FOR 1-1.
5. WHEN TWINNING THE S8B1 / S8X1 FURNACES, DISREGARD
THE W2 AND R2 WIRING.
From Dwg. 21B341337 Rev. 2
OUTDOOR UNIT
(WITH TRANSFORMER)
RC
ISOLATION RELAY
(FIELD SUPPLIED)
ALTERNATE CONNECTION
R
Y
TWINNING CONNECTION DIAGRAM
FOR TWINNING S-SERIES FURNACES
2 STAGE HEAT / 1 STAGE COOLING THERMOSTAT
WITH SINGLE STAGE THERMOSTAT
2 STAGE HEATING
1 STAGE COOLING
THERMOSTAT FURNACE NO. 1 FURNACE NO. 2
SEE NOTE 5
R1
ISOLATION RELAY
(FIELD SUPPLIED)
ISOLATION RELAY
R1
R1
1 STAGE ODU
(NO TRANSFORMER)
Y1
B
Y1 Y1 Y1
W1 W1
W1
W2 W2 W2
R R
R
G G G
B
B B
NOTES:
1. BOTH FURNACES MUST BE POWERED FROM
THE SAME 115 VAC PHASE LEG AT THE CIRCUIT BREAKER.
2. TRANSFORMERS MUST BE IN PHASE.
- MEASURE THE VOLTAGE BETWEEN THE “R” TERMINALS
ON BOTH FURNACES, VOLTAGE SHOULD BE LESS THAN
10 VOLTS.
- IF GREATER, REVERSE THE LOW VOLTAGE ON ONE OF THE
TRANSFORMERS AND RECHECK.
3. HEATING AND COOLING AIRFLOW MUST BE THE SAME FOR
BOTH FURNACES.
4. OD UNIT TYPE SETUP MUST BE THE SAME FOR BOTH FURNACES.
5. WHEN USING A SINGLE STAGE THERMOSTAT, JUMPER W1/W2
TOGETHER. THE INTERSTAGE DELAY MUST BE SET THE SAME
FOR BOTH UNITS.
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