Compressor Overload Tripping

Is your compressor tripping too often, causing your production line to shut down and wasting your valuable time? Frequent overload trips are not only annoying, but they are also a warning sign of potential problems. In this guide, we will analyze the causes of compressor overload trips and provide a step-by-step diagnostic method to help your equipment return to normal operation quickly.

Compressor Overload Tripping: Voltage

Voltage fluctuations are the number one cause of air compressor overload tripping. If incoming voltage drops below 90% or surges above 110% of the rated voltage (e.g., 198V–242V for a 220V system), the motor’s overload protector will trigger.

How to diagnose:

Use a multimeter to measure voltage at the compressor’s terminal during operation.
Check whether the cause of the compressor overload trip is due to loose wiring in the main circuit.
Pro Tip: Install a voltage stabilizer if fluctuations exceed ±10%.

’ Warm reminder: If you want to know more detailed troubleshooting methods and steps you can click here.

Compressor Overload Tripping: Motor

This is the most common cause of air compressor overload tripping.
Worn-out motors draw excessive current, tripping thermal overload relays.
Common signs include:
Burning smell from windings
Abnormal noise from bearings
Current exceeding nameplate rating (test with a clamp meter)

Quickly repair the compressor overload trip caused by this reason:

Reset the overload relay after a 30-minute cooldown.
Replace motors showing insulation resistance below 1MΩ (megohm).

Compressor Overload Tripping: Temperature

Overheating is also an important factor in the need to troubleshoot air compressor overload tripping.
Air compressors automatically shut down when discharge temps exceed 120°C (248°F) to prevent damage. Causes include:
Clogged oil cooler fins
Faulty cooling fan
Low lubricant levels

Steps to determine the cause of the compressor overload trip:

1.Inspect the temperature sensor with an infrared thermometer.
2.Clean debris from cooling fins using compressed air.

’ Warm reminder: Want to learn about overheating factor testing? Click here.

Compressor Overload Tripping: Faulty Starter or Contactor

Oxidation of the magnetic starter contacts increases resistance, forcing the motor to work harder. This causes the air compressor to overload and trip.

Symptoms:Clicking sounds without motor engagement
Burnt marks on contact surfaces

Handle the compressor overload trip caused by this fault:

Disconnect power and scrub contacts with fine-grit sandpaper.
Replace starters with pitted contacts deeper than 0.5mm.

Compressor Overload Tripping: Dirty Air Intake Filters

A clogged filter screen reduces airflow, causing the motor to overcompensate. This usually triggers the screw compressor to overload and trip.

How to prevent this type of air compressor overload trip problem？

Replace disposable filters every 3 months.
Wash reusable filters weekly in warm soapy water (if PM2.5 levels > 50).

Troubleshooting Flowchart

Follow this sequence to pinpoint issues:
Tripping on startup? Test power supply voltage.
Tripping mid-cycle? Check motor amps and cooling systems.
Random tripping? Inspect contactors and wiring.