Bryant 548C Series, Installation, Start-Up And Service Instructions Manual

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LEGEND
C — Contactor
HC — Heater Contactor
IFC — Indoor-Fan Contactor
OFC — Outdoor-Fan Contactor
RVS — Reversing Valve Solenoid
W
— Heating Stage
X — Contact Energized
Y — Cooling Stage
NOTES:
1. In heating mode, economizer damper blade will move to the mini-
mum position, and unit will operate as described for units without
economizer, regardless of outdoor air temperature.
2. The temperatures given in the graph are for demonstration purposes
only and may vary depending on which thermostat is used.
UNITS WITH ECONOMIZER
AVERAGE OUTDOOR-AIR TEMPERATURE GREATER THAN OAT SETTING
Thermostat Demand G Y1 Y2 W1 W2 C1 C2 IFC OFC RVS1 RVS2 HC
Second Stage Cooling X X X X X X X X X
First Stage Cooling X X X X X X X
Deadband (Offset)
First Stage Heating
X X X X
Second Stage Heating X X X X X X
AVERAGE OUTDOOR-AIR TEMPERATURE LESS THAN OAT SETTING, BUT GREATER THAN −2 C (28 F)
Thermostat Demand G Y1 Y2 W1 W2 C1 C2 IFC OFC RVSI RVS2 HC
Second Stage Cooling X X X X X X X X
First Stage Cooling X X X X X
Deadband(Offset)
First Stage Heating
X X X X
Second Stage Heating X X X X X X
UNITS WITHOUT ECONOMIZER
AVERAGE OUTDOOR-COIL TEMPERATURE LESS THAN −2C (28 F)
Thermostat Demand G Y1 Y2 W1 W2 C1 C2 IFC OFC RVSI RVS2 HC
Second Stage Cooling X X X X X X X X X
First Stage Cooling X X X X X X X
Deadband (Offset)
First Stage Heating
X X X X
Second Stage Heating X X X X X X
AVERAGE OUTDOOR-COIL TEMPERATURE GREATER THAN −2 C (28 F)
Thermostat Demand G Y1 Y2 W1 W2 C1 C2 IFC OFC RVSI RVS2 HC
Second Stage Cooling X X X X X X X X X
First Stage Cooling X X X X X X X
Deadband (Offset)
First Stage Heating
X X X X
Second Stage Heating X X X X X X
Fig. 31 — Typical Operating Sequence
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