Fault Codes / Daikin / U1

VRV / Sky Air — Reverse phase / open phase (rotation).

Possible causes

• Two phases swapped.
• One phase missing.

Check steps

• Check phase sequence, swap two phases if needed.
• Measure all phases at input.

Affected parts

• Phasenwächter
• Sicherungen
• Klemmenblock

Safety note

Source: Daikin SM-TS3 (Simple Self-Diagnosis by Malfunction Code, resmi) veya VRV IV+ Service Manual (ManualsLib) — SM-TS3 p.5: 'U1 Reverse phase, open phase — Power supply reverse phase, T phase open phase, Defective outdoor unit PCB (A1P)' — applies across all product lines including VRV.

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

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