Fujitsu ASU12RL2, AOU12RL2 Defrost Operation Control, Condition of Starting the Defrost Operation

18. DEFROST OPERATION CONTROL

1.CONDITION OF STARTING THE DEFROST OPERATION

The defrost operation starts as shown in the following Table 18.

(Table 18 : Condition of starting Defrost Operation)

Normal defrost

	Compressor integrating operation time
Less than 25 minutes		More than 25 minutes
		Outdoor heat exchanger temp. < -17°C (1.4°F)
Does not operate		=
		(at outside air temp. > -10°C (14°F))
		=
		Outdoor heat exchanger temp. < Outside air temp.
		=
		- 7°C (-44.6°F)
		or Outdoor heat exchanger temp. < - 20°C (-13°F)
		=	(14°F))
		(at outside air temp. < -10°C

Integrating defrost

Compressor integrating operation time

More than 240 minutes	More than 213 minutes	Less than 10 minutes
(For continuous operation)	(For continuous operation)	( For intermittent operation )
Outdoor heat exchanger	Outdoor heat exchanger	OFF count of the compressor
temperature below -3°C (-6°F)	temperature below -5°C (-10°F)	40 times

If the compressor continuous operation time is less than 10 minutes, the OFF number of the compressor is counted.

If any defrost operated, the compressor OFF count is cleared.

2. CONDITION OF THE DEFROST OPERATION COMPLETION

Defrost operation is released when the conditions become as shown in Table 19. (Table 19 : Defrost Release Condition)

Release Condition

Outdoor heat exchanger temperature sensor value is higher than +16°C (60.8°F) or

Compressor operation time has passed 15 minutes.

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