HIT

Hitachi 55

High

Set Free Sigma / IVX (FSXN) — Malfunction of the inverter PCB (PCB2) — abnormal output frequency

Hitachi 55: Malfunction of the inverter PCB (PCB2) — abnormal output frequency This fault noticeably affects operation.

Possible causes

PCB2 not operating normally (actual frequency falls below 10 Hz)
Damaged surge absorber due to lightning/surge event

Check steps

Power OFF and restart; if code 55 reappears, replace PCB2
Inspect surge absorber (SA) in NF1/NF2 for discoloration, replace if needed

Affected parts

PCB2 (inverter board)
Surge absorber (SA)
Noise filter NF1/NF2

Safety note

Disconnect power and wait the discharge time (min. 5 minutes) before opening the inverter housing.

Source: Hitachi resmi servis kılavuzu (bağımsız çift-doğrulandı) — Hitachi FSXN Series Service Manual, §8 Troubleshooting by alarm code, p.232 (manualslib.com/manual/2375584/Hitachi-Fsxn-Series.html?page=232): Alarm code 55 — "Inverter failure": actual output frequency from PCB2 falls below 10 Hz after the inverter frequency output from PCB1, i.e. PCB2 is not operating normally; ala…

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

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