Off Defrost Operation Control - Fujitsu AB*A30LBT Service Instruction

5-19. OFF DEFROST OPERATION 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.
and compressor operation contiguous time lasts for more than 10 minutes.
2. OFF DEFROST END CONDITION
Outdoor heat exchanger temperature sensor value is higher than +10°C or
Compressor operation time has passed 15 minutes.
OFF Defrost Flow Chart
Outdoor heat exchanger temperature:
Below - 4°C
and
Compressor integrating operation:
Over 30 minutes
and
Compressor contiguous operation:
Over 10 minutes
Outdoor heat exchanger temperature: Over 10°C
Compressor ON time: Over 15 minutes
Release Condition
Heating operation stop
Defrost start
Defrost Indicator:
[Operation lamp]
7 sec ON / 2 sec OFF
or
Defrost end
05-17