Sanyo XHX1852, UHX2452, UHX0752, UHX1252, UHX3652, UHX1852 F31 Alarm Alarm code, H03 alarm Alarm code

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Trouble Diagnosis

3. W-2WAY ECO-i Alarm Codes

F31 Alarm

Alarm code	F31
Alarm meaning	Outdoor unit non-volatile memory (EEPROM) trouble
Alarm conditions	(1)	Non-volatile memory is not present when power initialization occurs.
	(2)	Read values do not match after writing to non-volatile memory is complete.
Probable cause	(1)	Memory was not inserted after the PCB was replaced.
	(2) The lifetime of the non-volatile memory has been reached.
	(3)	Non-volatile memory is installed incorrectly (wrong direction, bent pins, etc.).
Check	(1)	Check the non-volatile memory on the PCB.
Correction	—
Example	—
Notes	—
H03 alarm
Alarm code	H03
Alarm meaning	Compressor CT sensor disconnected or short-circuit
Alarm conditions	Alarm occurs if the current value is 1.5 A or less when 2 seconds or longer have elapsed after
	output from that compressor started.
	* No current is detected even though the compressor is operating.
Probable cause	(1)	CT circuit failure (including cut wiring, etc.)
	(2)	Disconnected CT circuit connector
	(3) This CT circuit is connected to the connector of the other CT circuit.
	(4)	PCB failure
	(5)	Noise
Check	(1)	CT circuit failure, PCB failure
		Trouble: • Current value during compressor operation is below the threshold value.
		Check: • Check that the connector is not disconnected.
		• Check the continuity of the CT circuit.
		Install a normal CT in place of this CT and check. If current is detected, then the
		PCB can be judged OK.
		→ CT circuit failure
		• Check that current is flowing in the phase where the CT circuit is connected.
		→ Check voltage and current.
	(2)	Crossed wiring or installation error
		Trouble: When the compressor is stopped, the current value at the other compressor is high.
	(3)	If the cause is still unknown after checking the above, then it is possible that noise is the
		cause of the trouble. It is necessary to connect a PC or other instrument.
Correction	(1)	Replace the CT circuit.
	(2)	Replace the outdoor unit PCB.
	(3)	Correct the problem.
Example	(1) The connector was not inserted after the PCB was replaced.
Notes	Use a normal CT as a tool to determine whether the trouble is a PCB failure or CT failure.

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