Product data

DFB switches the unit back to normal heating operation. If the DFT remains closed the DFB switches the unit back
to heating operation after 10 minutes. When the DFB changes back to heating mode, the RVR (reversing valve
relay) is de-energized and the reversing valve switches back to heating operation. Both the outdoor and indoor fans
come back on, and if necessary, the electric heater also turns on.
System safeties
— The system is equipped with the following safety devices to protect system components:
A. Indoor coil freeze protection thermostat (cooling cycle only) — If a coil temperature of 28 F or lower is sensed,
the compressor and outdoor fan will be shut down until the coil temperature exceeds 28 F. The indoor fan will
continue to run.
B. Condensate float switch (units equipped with accessory condensate pump, cooling cycle only) — If the level of
condensate in the drain pan rises too high; the condensate float switch will turn off the compressor and outdoor
fan until the condensate level returns too normal. The indoor fan will continue to run.
C. Outdoor Unit Safeties — These units are protected by the following devices:
• High-pressure switch
• Loss of charge switch (condensing units only)
• Compressor internal overloads
• Outdoor fan motor internal overload
NOTE:
a high discharge gas temperature sensor also protects outdoor units with scroll compressors and a 2-minute
timer to prevent possible reverse rotation of the compressor. Should any of these devices trip after the compressor is
energized, the Cycle LOC™ protection device will lock out the outdoor unit (turn if off) to prevent cycling on a
safety device.
Special operation, heating
—Outdoor cooling units can be matched with heat pump ceiling-suspended or cassette
fan coil units to provide supplemental electric heat. All other operation is the same as a cooling only system, except
these units have heating capability as follows: When the room thermostat initiates a call for heating, the electric
heater is turned on. The indoor unit fan will start at the same time if it was not already running. When the heating
requirement is satisfied, the room thermostat will open, and the heater will turn off.
See (fig #3) for pictures of the three thermostats available