-

 36 

-

Serial signal transmission error

[Wiring error including power cable, defective indoor/
outdoor unit PCB]

Does error persist after power
reset?

Is there any wrong connection on
indoor/outdoor unit wiring?

Is DC 0~Approx. 12V detected
between 

2

~

3

 terminals on

indoor unit terminal block?

YES

YES

NO

NO

YES

NO

Trouble by transient cause, not unit trouble.

Correct improper wire connection on indoor/
outdoor unit.

Defective indoor unit PCB

YES

YES

NO

NO

Is DC 0~Approx. 12V detected
between

2

~

3

 terminals on

outdoor unit terminal block?

Is  AC 220/230/240V applied
between 

1

~

2

 on the outdoor side

terminal block?

Defective indoor unit PCB. Check crossover wires.

Defective outdoor unit PCB

Check crossover wires.

(4)

Phenomenon observed after shortcircuit, wire breakage on thermistor.

(a)

Indoor unit

Phenomenon

Thermistor

Shortcircuit

Broken wire

Cooling

Release of continuous compressor operation command

Heating

Continuous compressor operation command is not released.

Cooling

System can be operated normally.

Heating

High pressure control mode

(b)

Outdoor unit

Phenomenon

Thermistor

Shortcircuit

Broken wire

Cooling

System can be operated normally.

Heating

Defrosting is not performed.

Cooling

System can be operated normally.

Heating

Defrosting is not operated.

All modes

Operation
mode

Room temperature
thermistor

Continuous compressor operation command is not released.

Release of continuous compressor operation command

Continuous compressor operation command is not released.
(Anti-frosting)

Hot keep (Indoor fan stop)

Heat exchanger
thermistor

Operation
mode

System can be operated normally.

Defrosting is performed for 10 minutes at approx. 1 hour.

System can be operated normally.

Defrosting is performed for 10 minutes at intervals of approx. 1 hour.

Compressor stop

Heat exchanger
thermistor

Outdoor temperature
thermistor

Discharge pipe
thermistor

Compressor overload protection is disabled.
(Can be operated.)

Опубликовано TopClimat