Off Defrost Operation Control - Fujitsu AS* A09LEC Service Instruction

23. OFF DEFROST OPEARTION CONTROL
When operation stops in the [Heating operation] mode, if frost is adhered to the outdoor unit heat
exchanger, the defrost operation will proceed automatically. In this time, if indoor unit operation
lamp flashes slowly (7 sec ON / 2 sec OFF), the outdoor unit will allow the heat exchanger to defrost,
and then stop.
1. OFF DEFROST OPERATION CONDITION
In heating operation, the outdoor heat exchanger temperature is less than -4°C,
and compressor operation integrating time lasts for more than 30 minutes.
2. OFF DEFROST END CONDITION
Outdoor heat exchanger temperature sensor value is higher than
or Compressor operation time has passed 15 minutes.
OFF Defrost Flow Chart
Outdoor heat exchanger temperature :
Below
Compressor integrating operation :
Over 30 minutes
Outdoor heat exchanger temperature :
Compressor ON time : Maximum 15 minutes
Release Condition
Heating operation stop
-4°C
Defrost start
Defrost Indicater:
[Operation lamp]
7 sec ON / 2 sec OFF
Over +16°C
or
Defrost end
+16°C
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