Air Compressor Fault — Motor High Current
What This Fault Means
A high current fault indicates the compressor motor is drawing more current than the overload setting allows. The motor protector or VFD trips to prevent winding damage.
Common Causes
- Low voltage supply (causing higher current to maintain load)
- Worn compressor element bearings increasing mechanical drag
- Oil separator element clogged (high backpressure on the element)
- Minimum pressure valve stuck closed
- Loose or corroded power connections causing voltage drop
Recommended Fix
- Measure voltage at the motor terminals under load — should be within ±10% of nameplate.
- Check the differential pressure across the oil separator — replace if >1 bar / 15 psi above baseline.
- Verify the minimum pressure valve opens above its set point (~4.5 bar / 65 psi).
- Inspect motor terminal connections for corrosion or looseness.
- If current is high at unloaded state, suspect compressor element bearing wear.
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