Compressor Drawing High Amps
Tripping Breakers or Seeing High Amp Readings?
If your air compressor is pulling more amps than normal, tripping breakers, or triggering overloads, it’s time to dig into what’s behind the power spike. High amperage draw usually means your compressor is working harder than it should, or else something’s gone electrically sideways. Whether you’re using a reciprocating compressor, a portable rotary screw, or a stationary rotary screw compressor, here’s how to troubleshoot the issue.
If You Have a Reciprocating or Portable Rotary Screw Compressor
On these machines, high amp draw typically points to airflow restriction or mechanical resistance. If your motor sounds like it’s straining, or your breaker keeps popping, start with the basics.
Top Causes:
- Dirty Air Filter – Restricts intake and increases motor load.
- Incorrect Voltage Supply – Low voltage = high current draw.
- Slipping or Overtightened Belts – Can cause drag and resistance.
- High Discharge Pressure – Trying to hit an overly high PSI target can overwork the motor.
- Mechanical Seizure – Bearings or pump internals may be locking up.
Fixes to Try:
- Replace your air filter if it’s dirty, clogged, or damp.
- Check voltage at the outlet. Especially with long cords or shared circuits.
- Inspect belts for proper tension. Not too loose, not too tight.
- Lower your pressure setting and see if the amp draw decreases.
- Turn the pump by hand (with the power off) to check for mechanical resistance.
If You Have a Stationary Rotary Screw Compressor
Rotary screw compressors pulling high amps may be compensating for restrictions, improper startup settings, or even a failing air end. Because these systems often run on 3-phase power, electrical issues are a common culprit.
Likely Causes:
- Clogged Inlet Filter or Separator – Starves airflow and increases load on the motor.
- Inlet Valve Not Opening Fully – Causes the compressor to fight for air.
- High Pressure Setpoint – System works harder to reach and maintain elevated PSI.
- Phase Imbalance or Low Voltage – One weak leg of power will spike current draw on the others.
- Airend Damage or Drag – If bearings are worn or rotors are dragging, amp draw rises fast.
Steps to Fix It:
- Inspect and clean your inlet filter and replace the separator if due.
- Verify inlet valve movement. Repair or replace inlet valve if it’s sticking.
- Adjust the controller to a more reasonable pressure target.
- Use a multimeter to check voltage across all three phases.
- If air end resistance is suspected, consult your service provider for inspection.
Prevent High Amp Problems
For Reciprocating and Portable Compressors
- Never use undersized extension cords. Always plug directly into a dedicated outlet.
- Replace air filters on schedule, especially in dusty environments.
- Check belt tension monthly and adjust for wear.
For Stationary Rotary Screw Compressors
- Include voltage and amp draw checks in your PM routine.
- Inspect filters, separators, and inlet valves during every service visit.
- Document phase balance during electrical inspections to spot hidden issues early.