• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar

Air Compressor Plus

  • Home
  • Air Compressor
    • Best Cheap Air Compressor
    • Best Garage Air Compressor
    • Best Portable Air Compressor for Car
    • Best Quiet Air Compressor
    • Best Small Air Compressor
    • Best Value Air Compressor
    • By Purpose
      • Best Air Compressor for Car Tires
      • Best Air Compressor for Home Use
      • Best Air Compressor for Money
      • Best Air Compressor for Painting Cars
    • By Size
      • Best 20 Gallon Air Compressor
      • Best 30 Gallon Air Compressor
      • Best 6 Gallon Air Compressor
    • By Brand
      • Craftsman
      • DeWalt
      • Husky
      • Porter Cable
  • Guides
  • About Us
  • Affiliate Disclosure

How to test an air compressor capacitor

by Ivan Sanchez | Last Updated April 29, 2022

The capacitor’s primary function is to store electrons in order to give start-up energy for your air compressor. When electricity runs through them, they generate a charge by transferring electrons between the two conducting plates contained within.

Diverse capacitors perform different functions in air compressors, and the run capacitor, which is used to improve the running efficiency of the compressor’s motor, is one of them. Following the heavy load and working for an air compressor, some capacitors fail, while others slow down.

So, we often had to test capacitors in an air compressor to find out how effective and efficient they are and how long they will last. If you are also testing a capacitor and are interested in learning how to test a capacitor in an air compressor, you have come to the right place.

 

Contents

  • A basic way to test an air compressor capacitor:
  • Determine the capacitor’s high and low points
  • Testing a motor run capacitor of an air compressor
  • The best way to know whether a capacitor has blown or not:
  • Conclusion

A basic way to test an air compressor capacitor:

For an electrolytic capacitor with a large capacity that serves as the start capacitor for the air-conditioning compressor.Testing should be done with a digital multimeter set to its capacitance setting to identify whether or not there is an issue.

As a general rule, when you use a multimeter, you should be able to tell how much capacitance a capacitor has by looking at how close it is to the capacitance it should have.

If it doesn’t match or is very close to the capacitance that a multimeter should have, you should get a new one.

Connect the two test lines to the compressor start capacitor’s poles. Ensure that the capacitor being examined is fully depleted or that the circuit is turned off before using a multimeter. A voltage that is too high can harm the meter or you.

The capacitance value is expressed in farads, and the multimeter is set to the ohm scale. Under typical circumstances, the multimeter’s pointer swings to the right until it reaches a fixed position, then gradually swings to the left until it reaches a fixed position.

If the pointer does not swing or has a limited swing range, this shows that the compressor capacitor’s performance is inadequate.

 

Determine the capacitor’s high and low points

This can be accomplished with a DMM. At first, the needles should be connected to the capacitor’s terminals. If you have connected the positive needle to the negative terminal, it will show negative sign.

Afterward, check to see if the reading matches the range of numbers on the capacitor’s label. In addition to the capacitor’s other characteristics, the minimum and maximum capacitances are listed on the capacitor’s side. The permissible range is dependent on the capacitance of the device you’re working with.

If the capacitor is found to be outside of the specified range, it must be replaced. It is necessary to replace the capacitor if the capacitance number increases indefinitely to the maximum capacity of your multimeter. Certain capacitors have a fixed capacitance with a tolerable proportion of variation.

 

Testing a motor run capacitor of an air compressor

To test an air compressor capacitor, you first need to remove the cap.Then with the help of an ohm meter, you set the resistance and by resistance, it should be kept high. After that, connect the meter to the cap with a wire.

Observe how the resistance changes from zero to infinite in a matter of seconds and then reverse the leads and repeat the same procedure.

If you obtain a continuous value of zero ohms, the cap is shorted; if you obtain a continuous value of Meg ohms or greater, the cap is open.

If the resistance remains low after a few seconds, it is shorted; at that point, it should be essentially open.

In the next step, you should check to verify if it is open or in good condition. When the multimeter leads are connected to the cap and the meter is set to measure ohms, the meter should first report low resistance but gradually increase resistance as it charges.

Motor running capacitors are utilized in series with the secondary coil on a permanent basis. These capacitors have a significantly greater voltage than the supply voltage.

These capacitors are fundamentally electrolytic.

The motor start capacitor is also connected in series with the supplementary winding, but the winding configuration is different and the capacitor voltage is 230 V for a 220/230 V supply.

The capacitor has a much greater value and is only in the circuit for a brief time of little under three seconds.

 

The best way to know whether a capacitor has blown or not:

To get straight with it, I must add that the only method to know is to use a capacitance meter to measure the capacitance.

Some DVMs are equipped with a C meter, although these are designed to measure big value caps, like the ones found on motors and compressors in air conditioners, rather than small value caps.

Using a pair of welding irons one for each side to remove a surface – mounted capacitor from its surface reveals that the capacitor is faulty.

 

Conclusion

The function of the capacitor is to construct a three conductor circuit to the one conductor circuit consisting of one neutral wire for power supply. Compressors were never intended to function without the assistance of a motor-run capacitor.

Usually, problems take place when the replacement occurs between the start and the run capacitor of an air compressor but there is nothing that can be neglected aith testing procedure of air compressor. Now with all of this information provided by us, we hope that you are getting something meaningful.

Filed Under: Guides

About Ivan Sanchez

Ivan Sanchez is a passionate blogger, traveler and certified Mechanic and moreover owns a Mechanic Shop in Norway too. He loves Painting Cars, Fixing them and a lot more. His father had a shop too where he used to sell Air Compressors, that's where Ivan learned about it and now reviewing some top-notch air compressors through this blog for you.

Recent Posts

  • How To Make A Confetti Cannon With An Air Compressor
  • How To Keep Air Compressor From Freezing
  • How To Install Oil Water Separator On Air Compressor
  • How To Increase Air Compressor Capacity
  • How To Clean An Air Compressor Tank
  • How To Build A Soundproof Box For Air Compressor
  • How To Blow Up Raft With Air Compressor
  • How To Add A Storage Tank To An Air Compressor
  • How Often To Drain Air Compressor
  • VIAIR 400p portable compressor review
  • Home
  • Affiliate Disclosure

Copyright © 2023 ·