When you first invest in an air compressor, it makes sense to plan for the power it is likely to use. After all, these can be very powerful machines! The last thing you will want is for your compressor to trip your fuses and circuits.
The number of amps your air compressors will use depends on your make and model. Different air compressors operate at different rates of horsepower (HP). This means the demand for amps will be higher the more powerful your compressor is.
If you’ve taken a good look through your operations manual and are still not clear on how many amps your new air compressor is likely to use, keep reading for a quick way to work out the average demand.
PLEASE NOTE: The following is to be used as a general guide ONLY – NEVER change or adjust your home electrical supply without the guidance of a trained electrician. Or, even easier, ask an electrician to take a look at your amperage for you before you set up your air compressor for the first time.
How many amps an air compressor uses – a simple formula
The average air compressor is likely to use around 4 amps per one third horse power. With the formula looking like this:
Amp = 4*(HP*3)
Therefore, if you have a compressor with a motor that runs at 3 HP, for example, you can expect it to draw up to 36 amps. That’s likely to be much more than your standard 15 to 20 amp breaker is going to be able to handle.
So, for a standard 15 amp home circuit breaker, you will likely be safe to use an air compressor with a motor running at 1 HP – but no more.
It is important to calculate these numbers before you start using your air compressor in your garage, as overpowering your circuit breaker will spell trouble for other electrical items in your home.
It is therefore all the more likely you will get safe mileage from a heavy-duty air compressor through a separate generator. Otherwise, you may have to fit a specialist fuse and/or circuit breaker.
Why is it important to know how many amps an air compressor uses?
Basic home electrical circuits use fuses and breakers. You are ultimately limited by how large your home power supply actually is – and more often than not, your compressor’s manufacturer is not on hand to advise on such matters.
They will simply tell you the HP of your compressor motor, and it is otherwise down to you to check that you have enough current flowing through to support your new machine.
Generally, a home running on a basic 120V AC power supply will support an air compressor running at 1 HP. However, as mentioned above, it pays to ensure you have adequate fuses and breakers in place.
Otherwise, you are not only likely to put strain on other electricals in your home, but you could damage or blow a fuse. That is going to be a completely different problem you might not want to deal with – so trust us, it pays to plan ahead!
Try and keep your air compressor on a clean circuit
Even if you are running your new air compressor in your garage, and there are no other electrical items plugged into your extension or outlet, you still need to ensure you are running your compressor on a ‘clean’ supply. But what do we mean by this?
Essentially, you need to make sure that you are not running your air compressor on a circuit or breaker that has other home essentials relying on it. If you take a look at your home fuse box, you will likely see that there are different fuses and circuits with devices aligned on communal circuits. For example, you may find that your garage outlets are on the same circuit as your washer dryer, your refrigerator, or even the lights on the ground floor.
Now – if you risk adding additional strain to that circuit, you could risk blowing both the supply and any devices connected to it. That is why it is so important to try and provide something as amp-intensive as an air compressor with clean, sole access to its own circuit.
Again, it is extremely important to consult the advice of an electrician, unless you yourself are a trained professional. We would never advise adjusting or changing your fuses and breakers unless you are 100% clear on what you are doing! There is not only a risk to fusing your home electrical supply, but a risk of injury or fatality when improperly handling home power connections.
Conclusion
In most cases, smaller or less powerful air compressors specifically designed for home use will likely use very little amperage. In some other cases, you may find that your manufacturer provides you with the information you need to safely set up your device in line with your current fuses and breakers.
However, it does still pay to prepare far in advance of setting up. By using our quick formula above, it may become clearer as to how much power your new air compressor actually needs.
Air compressors need a fair amount of TLC and preparation – and one last time, DON’T go messing with the electrics unless you’re trained to, or you know someone who can assist.