Fault Codes / Mitsubishi Electric / 4220

City Multi — Abnormal bus voltage (drop/rise).

Possible causes

• Supply voltage out of range.
• INV board / noise filter faulty.

Check steps

• Measure mains L1-L2-L3 (≥342 V all phases).
• Check INV board/noise filter.

Affected parts

• INV-Board
• Noise-Filter

Safety note

Source: Mitsubishi Electric City Multi Fault Code List (offiziell, 2024-10)

Reviewed by Anıl Güzeldemir — in the refrigeration machine room since 2006, developer of Enthalio.

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