Fujitsu R410A - Off Defrost Operation Control

24. OFF DEFROST OPERATION CONTROL
1. OFF DEFROST OPERATION CONDITION
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.
In heating operation, the outdoor heat exchanger temperature is less than 24.8°F(-4°C), and
compressor operation integrating time lasts for more than 30 minutes.
OFF Defrost Flow Chart
Heating operation stop
Outdoor heat exchanger temperature :
Below
24.8°F(-4°C)
and
Compressor integrating operation :
Over 30 minutes
Defrost start
Defrost Indicator:
[Operation lamp]
7 sec ON / 2 sec OFF
Outdoor heat exchanger temperature : Over 55.4°F(13°C)
or
Compressor ON time : Maximum 10 minutes
Defrost end
2. OFF DEFROST RELEASE CONDITION
Release Condition
Outdoor heat exchanger temperature is higher than 55.4°F(13°C)
or
Compressor operation time has passed 10 minutes.
( Table 23 : OFF Defrost Release Condition )
OFF defrost operation is released when the conditions becomes as shown in Table 23.
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