Sanyo CH1271, CH0971 service manual Defrost detection and release, CT Peak current cut-off control

Defrost detection and release

Reverse-Cycle Defrosting

Defrosting Sequence

Heating operation

Outdoor fan ON 4-way valve ON

Frost sensing

Defrost detection occurs in either of the following cases:

•The temperature of the heat exchanger remains at or below the L1 line for 3 minutes after the start of HEAT operation.

•The temperature of the heat exchanger remains at or below the L2 line for 120 minutes after the start of HEAT operation.

Outdoor heat
exchanger temp.	0
		Ambient temp.

L2

L1

Frosting area

Reverse-cycle defrosting operation

Compressor	1 minute after it is stopped,
Outdoor fan		compressor is ON.
	OFF
Indoor fan	OFF
4-way valve	OFF
Operation lamp		Repeatedly switches between red
		and orange illumination.

Releasing of defrosting

Outdoor heating exchanger temp. is over 68°F(20°C). Defrosting operation lasts 12 minutes (maximum).

2 minutes after it is stopped, compressor is ON.

4-way valve is ON. Outdoor fan is ON.

NOTE

If the air conditioner is turned off during the defrosting cycle, it will continue defrosting and turn itself off after defrosting is completed.

CT (Peak current cut-off control)

•This function prevents the circuit breaker or fuse from operating to open the circuit. This function works when electrical current has increased due to an increase in the cooling / heating load, or to a decrease in the power supply voltage. In these cases, operation frequency is reduced or operation is interrupted auto- matically to control the electrical current for operation.

•When the cause of the increase in electrical current is rectified, the system will resume operation in the original mode.

(A)

	Cooling	Dry Heating
Peak current cut-off trips		22.5
Hz down	14.0	15.0

NOTE Electrical current setting for COOL operation is used during DEFROST operation.

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