Fanuc alarm SV0438: INVERTER CURRENT ABNORMAL (n AXIS)
0i-D servo alarm (power circuit) · Fanuc 0i-D
What it means
Motor current measured far above command/current-limit - hardware-level overcurrent in the axis amplifier
Likely causes
- servo amplifier power stage (IPM/IGBT) failure
- motor winding short or insulation breakdown
- phase-to-phase short in motor power cable
- wrong phase sequence after cable work
Triage note: Megger the motor and disconnect motor leads before swapping the amp - a shorted motor will kill the replacement amplifier instantly
Replacement parts
We supply the following units for this alarm — tested, warranty-backed:
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A06B-6134-H303
Servo Amplifier Unit (beta i SVM) · Primary suspect
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A06B-2082-B105
AC Servo Motor (insulation test first) · Common cause
Need the part urgently?
Send us alarm SV0438 with your machine details — typical RFQ turnaround is 24–48h.