NOTE
IF SAFETY CIRCUITS ARE IN ONLY ONE OF THE SYSTEMS, REMOVE THE TRANSFORMER OF THE SYSTEM WITH NO SAFETY CIRCUITS.
|
| O | Y1 | Y2 | G |
CUT AND |
| CHANGEOVER | COMPRESSOR |
| |
| ENERGIZED | CONTACTOR |
| ||
TAPE OFF! |
| ||||
IN COOL | STAGE 2 |
| |||
HOT |
|
|
|
|
|
120 VAC | 24 VAC |
| COMPRESSOR | FAN | |
|
|
| CONTACTOR | ||
|
|
| RELAY | ||
NEUTRAL |
|
| STAGE 1 |
| |
|
|
|
| ||
B | W1 | W2 | A1 |
| HEAT |
|
|
| RELAY |
| DAMPER |
| STAGE 1 |
|
|
CHANGEOVER | HEAT |
| |
ENERGIZED |
| RELAY |
|
IN HEAT |
| STAGE 2 |
|
THERMOSTAT
CONTROL
CIRCUIT
THERMOSTAT
RC
SYSTEM
HOT
|
|
|
|
|
|
|
24 VAC |
|
|
|
|
| 120 VAC |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
NEUTRAL
DEPENDING ON SYSTEM
REQUIREMENTS, REPLACE WITH A 75VA TRANSFORMER, IF NEEDED
TWO COMMONS MUST
BE JUMPERED TOGETHER!
Figure 5. Typical wiring diagram for
NOTE
Relay contacts shown are thermostatically operated. The accessory relay scheme is required when safety circuits exist in both systems.
!CAUTION
Polarity must be observed. If the HOT side of the second transformer is jumpered to the COMMON side of the first transformer a short will be made. Damage to equipment will occur when power is restored.
THERMOSTAT
CONTROL
CIRCUIT
THERMOSTAT
O | Y1 | Y2 | G | B | W1 | W2 | A1 | C | R |
CHANGEOVER |
| COMPRESSOR |
| HEAT |
|
|
ENERGIZED |
| CONTACTOR |
| RELAY |
| DAMPER |
IN COOL |
| STAGE 2 |
| STAGE 1 |
|
|
|
|
|
|
|
|
|
SYSTEM
|
|
|
|
|
|
|
|
| LIMIT OR |
|
|
|
LIMIT OR |
|
|
|
|
|
|
|
| SAFETY |
| HOT | |
SAFETY | 24 VAC |
|
|
|
|
| 120 VAC | SWITCHES |
|
|
| |
SWITCHES |
|
|
|
|
|
|
|
|
| |||
|
|
|
|
|
|
|
|
|
|
|
| |
|
|
|
|
|
|
|
|
|
| NEUTRAL | ||
|
|
|
|
|
|
|
|
|
| |||
|
|
|
|
|
|
|
|
|
|
|
|
|
COMPRESSOR |
| FAN |
| CHANGEOVER |
| HEAT |
CONTACTOR |
|
| ENERGIZED |
| RELAY | |
| RELAY |
|
| |||
STAGE 1 |
|
| IN HEAT |
| STAGE 2 | |
|
|
|
| |||
|
|
|
|
|
|
|
TWO COMMONS MUST
BE JUMPERED TOGETHER!
24 VAC
ACCESSORY RELAY N.O.
CONTACT
COMMON
LIMIT OR
SAFETY
SWITCHES
COMMON | 24 VAC |
HEATING
TRANSFORMER
LIMIT OR
SAFETY
SWITCHES HOT
120 VAC
NEUTRAL
COOLING
TRANSFORMER
Figure 6. Typical wiring diagram for
5
