Error code reference

LG Air Conditioner Error Code 74

3-phase power unbalance: difference between R and T phase current exceeds 5A for 10 seconds during operation above 50Hz.

SourceLG Air Conditioner - Service Manual: Heat Recovery Outdoor Unit R410A (ARUB80LT2)p. 142

LG codes LG air conditioner codes

Diagnostic procedure

The full 74 procedure

Step 1 is visible so you can confirm you are on the right page. The remaining steps, the ones that tell you whether to actually replace a part, unlock with any pass.

MyPros+ · DiagnosticsStep 1 preview

First diagnostic step

Check inverter PCB assembly power wiring to bridge diode; check input voltage; check indoor unit power bridging.

SourceLG Air Conditioner - Service Manual: Heat Recovery Outdoor Unit R410A (ARUB80LT2)p. 142

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More steps, wiring diagram references, and verified part numbers

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Where this code is documented

2 manuals in the MyPros+ library document this code for LG air conditioner.

Models covered by the manuals that document this code

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The full 74 procedure

Where this code is documented

Models covered by the manuals that document this code

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