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Symptom: DXG-18, DXH-18, MGC-18 – ERROR CODE U3

Solution: MULTIPLE SOLUTIONS

Cause: DC BUS VOLTAGE DROP MALFUNCTION

Remarks:

DESCRIPTION:

*AC UNIT IN COOLING/DRY MODE: THE COMPRESSOR STOPS OPERATING WHILE THE INDOOR FAN WILL CONTINUE TO OPERATE.

*AC UNIT IN HEATING MODE: THE COMPLETE UNIT STOPS OPERATION.

REPAIR:

1) SUPPLY VOLTAGE IS UNSTABLE:

SOLUTION 1) CHECK IF THE POWER VOLTAGE IS STABLE OR NOT. IF NOT, PLEASE ADD A VOLTAGE REGULATOR

2) WRONG WIRING CONNECTION OF INDOOR UNIT:

SOLUTION 2) RECONNECT THE WIRING

3) PROTECTIVE TUBE IS MALFUNCTIONING:

SOLUTION 3) REPLACE IT WITH A NEW CORRESPONDING PROTECTIVE TUBE

4) TRANSFORMER IS MALFUNCTIONING:

SOLUTION 4) REPLACE IT WITH A NEW CORRESPONDING TRANSFORMER

5) THE PCB IS MALFUNCTIONING:

SOLUTION 5) REPLACE IT WITH A NEW CORRESPONDING PCB