Mitsubishi Electronics MUZ-GB50VA service manual Check of current-limiting resistor, Check of LEV

Outdoor unit does not operate at all, or stops immediately due to overcurrent.

F Check of current-limiting resistor

When the current-limiting resistor is open, the rush current limiting relay (X64) may not work properly.

Is the resistance of current-limiting resistor (R64A or R64B) on the noise filter P.C. board normal? (Normal resistance : 10' i5%)

Open

Replace the power P.C. board.

Not	Turn ON the power
open	supply and press
	EMERGENCY
	OPERATION switch.

Does LED on the outdoor electronic control P.C. board light up?

Yes

Does the rush current limiting relay (X64) work properly?

No

Yes

Replace the noise filter P.C. board or the outdoor electronic control P.C. board.

Replace the outdoor electronic control P.C. board or power P.C. board or the compressor.

No

Replace the noise filter P.C. board.

●Check other electric parts in the main circuit together in the case that the current-limiting resistor is defective.

•When cooling, heat exchanger of non-operating indoor unit frosts.

•When heating, non-operating indoor unit get warm.

G Check of LEV

Turn on power supply to the outdoor unit after checking LEV coil is mounted to the LEV body securely.

Is "click - click" sound heard?

Or, do you feel vibration of the LEV coil with a hand?

No

Disconnect the connector CN795.

Is there normal resistance to LEV coil?

No

Replace the LEV coil.

Yes

Normal

Yes Replace the outdoor electronic control P.C. board.

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