Fields Wiring Diagram - Twinning Ud-R Furnaces - American Standard *UD Series Operation Manual

Field Wiring Diagram for Twinning UD-R Furnaces
with Two Stage Heat and Single Stage Cooling Thermostat
LEGEND
RFS. REVERSE FLOW SWITCH (PROVIDED)
IFC INTEGRATED FURNACE CONTROL
RELAY A PILOT DUTY RELAY (PROVIDED)
Models may be an A or T
Field Wiring Diagram for Twinning UD-R Furnaces
with Two Stage Heat and Two Stage Cooling Thermostat
LEGEND
RFS. REVERSE FLOW SWITCH (PROVIDED)
IFC INTEGRATED FURNACE CONTROL
RELAY A PILOT DUTY RELAY (PROVIDED)
Models may be an A or T
SEE NOTE 4
SEE NOTE 4
37
NOTES:
1. REVERSE FLOW SWITCHES MUST BE INSTALLED ON EACH
FURNACE BLOWER HOUSING.
2.. IF OUTDOOR UNIT HAS A 24 VOLT TRANSFORMER, ISOLATING
RELAY MUST BE INSTALLED (FIELD SUPPLIED). USE PILOT DUTY
RELAY SUCH AS RLY0975.
3. CONNECT SPECIAL TWINNING CABLE (PROVIDED) BETWEEN
INTEGRATED FURNACE CONTROLS.
4. 24 VOLT TRANSFORMERS ON FURNACES MUST BE PHASED
PROPERLY.
From Dwgs. 21B148296 Rev. 0
NOTES:
1. REVERSE FLOW SWITCHES MUST BE INSTALLED ON EACH FURNACE
BLOWER HOUSING.
2.. IF OUTDOOR UNIT HAS A 24 VOLT TRANSFORMER, ISOLATING RELAY
MUST BE INSTALLED (FIELD SUPPLIED). USE PILOT DUTY RELAY
SUCH AS RLY0975.
3. CONNECT SPECIAL TWINNING CABLE (PROVIDED) BETWEEN
INTEGRATED FURNACE CONTROLS.
4. 24 VOLT TRANSFORMERS ON FURNACES MUST BE PHASED
PROPERLY.
From Dwgs. 21B148297 Rev. 0