If you can avoid using an extension cord with your air compressor, do so, but if you can’t, how do you know what size extension cord for an air compressor is the right size?

After all, there are few things aside perhaps from not putting air compressor oil in an oil lubed compressor pump, that can damage the compressor than using a too long or too light extension cord.

The same can be said of an electric power bar. It might be convenient if the pressure switch does not have an ON/OFF switch, to use the ON/OFF on the power bar to cut power to the compressor. That convenience comes at a cost, however.

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Extension Cords vs. Air Lines

My advice has always been, if you need the air compressor at the work site, instead of adding way too small 100m extension cord to try and feed power to the compressor, leave the compressor plugged into the wall socket, and run a longer air line out to the work place where air is needed.

A longer air line will quite likely cost less than buying the appropriate length of heavy duty extension cord and could save your compressor motor from unnecessary maintenance.

What Size Extension Cord For An Air Compressor.html
What Size Extension Cord For An Air Compressor.html

I recommend that you do not use a consumer-type power bar ever. They typically aren’t capable of channeling the power demands of all but the smallest fractional HP air compressor motors need to run properly, without damage due to undercurrent.

If you decide that you absolutely must have an extension cord, make sure it’s big enough for the compressor.

What follows are only guidelines to help you from disastrously under-powering your compressor motor.

You must exercise due diligence to ensure that the extension cord you use will actually adequately power and not damage your compressor motor.

What Size Extension Cord for an Air Compressor?

Using too small or too long an extension cord with your air compressor can result in the motor overheating and eventually the compressor motor may burn out if used for too long of a period.

An undersized cord is likely to cause your compressor motor overheat switch to shut down the motor due to the amount of heat being built up. This switch, sometimes referred to as the thermal cut out, is there to prevent overheating of the motor that will cause damage.

When deciding upon what size extension cord is most suitable for you compressor, you must consider the following:

  • On start up the compressor motor draws much more current than when the motor is up and running
  • The distance from the electrical panel to the outlet where the compressor is plugged in must be added to the overall wire length
  • The circuit breaker must be of sufficient amperage for the HP of the motor
  • Copper wire has considerably greater power carrying capacity than does aluminum
  • A too light gauge and lengthy extension cord can overheat and catch fire if the load exceeds it’s capability
  • The temperature where the extension cord is in use can reduce the capability of the extension cord to carry power
  • If in doubt, oversize the extension cord wire
  • Wires are bigger in diameter the smaller the gauge number
  • I would not recommend 14 gauge wire, and would never use #16 gauge, for use as an extension cord to a compressor motor

Voltages & Horsepower vs Extension Cord Guide

Now if you really must use an extension cord, you must ensure it is able to deliver the power required by the air compressor itself otherwise you run the risk of under powering your unit.

I must reiterate, please ensure you exercise due diligence when deciding whichever cord you can use to power your air compressor adequately.

The following guide can help you gauge what distance of cord you need depending on the compressors motor voltage, horsepower and breaker amperage. You will be able to to find this information on the name plate of your air compressor, and if not, refer to your manual or contact the manufacturer.

It’s important to note, this is just a rough guide and for exact figures, or for voltages and HP’s not shown in my graphic, visit any of the following websites or conduct your own deeper research for more information:

Extension Cords Available on Amazon

Here are some extension cords readily available on Amazon. These are just examples, please ensure that the extension cord you pick is suitable for your air compressor.

  1. Southwire 2588SW0002 Outdoor Extension Cord

2. Clear Power 25 ft TPE Rubber Heavy Duty Extension Cord

3. Outdoor Indoor Extension Cord

Do you have any questions about what size extension cable you need for your air compressor? Please leave a comment below and a photo if applicable so that someone may help!