Wiring Diagram For Single Transformer Systems - White Rodgers 1F89-211 Installation And Operation Instructions Manual

O/B
Changeover
Relay*
* Changeover Relay is energized in COOL when O/B switch is in the "O" position
Changeover Relay is energized in HEAT when O/B switch is in the "B" position
** Jumper required to use a single Aux Heat for both Second Stage Heat and Emergency
NOTE
If safety circuits are in
only one of the systems,
remove the transformer
of the system with NO
safety circuits.
CUT AND
TAPE OFF!
Changeover
HOT
120 VAC 24 VAC
NEUTRAL
* Changeover Relay is energized in COOL when O/B switch is in the "O" position
Changeover Relay is energized in HEAT when O/B switch is in the "B" position
** Jumper required to use a single Aux Heat for both Second Stage Heat and Emergency
Figure 3. Typical wiring diagram for two transformer systems with NO safety circuits
O/B Y G
Changeover Fan
Relay* Relay
Compressor
Contactor
* Changeover Relay is energized in COOL when O/B switch is in the "O" position
Changeover Relay is energized in HEAT when O/B switch is in the "B" position
** Jumper required to use a single Aux Heat for both Second Stage Heat and Emergency
Figure 4. Typical wiring diagram for two transformer systems with safety circuits in BOTH systems
Y G
Fan
Compressor
Relay
Contactor
(Stage 2)
Figure 2. Typical wiring diagram for single transformer systems
O/B Y G
Fan
Relay* Relay
Compressor
Contactor
W2 E C
See Note **
Emergency
MONITOR
Relay
Aux
Relay
(Stage 2)
TWO COMMONS MUST
BE JUMPERED TOGETHER!
W2 E C
See Note ** SYSTEM
MONITOR
Emergency
SWITCH
Aux
Relay
Relay
W2 E C
See Note **
MONITOR
Emergency
Relay
Aux
Relay
(Stage 2)
TWO COMMONS MUST
BE JUMPERED TOGETHER!
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.
L R
Limit or
Safety
Switches
SYSTEM
SWITCH
24 VAC
ACCESSORY
RELAY N.O.
CONTACT
COMMON
Limit or
Safety
Switches
24 VAC
COMMON
Heat Pump Transformer
(Class II current limiting)
3
THERMOSTAT
L R
SYSTEM
Hot
24 VAC 120 VAC
Neutral
TRANSFORMER
(Class II current limiting)
THERMOSTAT
L R
SYSTEM
SYSTEM
Limit or
Safety
SWITCH
Switches
24 VAC
TRANSFORMER
(Class II current limiting)
NOTE
THERMOSTAT
SYSTEM
Limit or
Safety
Switches
24 VAC 120 VAC
Auxiliary
NOTE
Heating
Transformer
The accessory relay scheme
(Class II
is required when safety
current
circuits exist in both systems.
limiting)
Limit or
Safety
HOT
Switches
120 VAC
NEUTRAL
Hot
120 VAC
Neutral
HOT
NEUTRAL