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Ask Atlas Copco: Electricity and Compressor Misconceptions


Ask Atlas Copco is a segment that discusses commonly asked questions about various compressor, vacuum, and blower technologies, processes and best practices. Today’s answer comes from Deepak Vetal, oil-free product manager.

 Last week, we talked about the history of the horsepower rating. The amount of work a compressor can do is a top concern for people researching a new compressor. With the help of an expert, people typically do a good job calculating necessary cfm, pressure and horsepower. But one thing they don’t usually think about is what happens to their electrical system once the compressor is plugged in.

We get a lot of questions on how much voltage a compressor will draw once it’s connected to the facility’s electrical system. A mistake we often see is people attempting to install compressors that are going to be too much for the facility’s electrical system. It’s important make sure that your system can put out more voltage (V) than your compressor requires. For instance, if your compressor is drawing 500 V, then your system should be able to supply more than that. Otherwise, you risk overloading your electrical wiring.

Another common misconception is that voltage and amperage are inversely related. Let’s think about an analogy. Think of electrical current in wiring like water in pipes where voltage is the water pressure, current is the rate of flow and resistance is the pipe size. As you increase the water pressure, the flow rate is going to increase. Similarly, if you increase the voltage in an electrical system, the amperage also increases. They are not inversely related, and shouldn’t be treated as such.

Finally, many people install compressors far away from where the actual electrical connection is. When they do this, they use an extension cord of some kind to connect the two. Think back to the water analogy. If you are sending a great deal of pressure and flow through small pipes, you’re going to have a problem. The same goes for electricity. The longer a wire is, the more resistance it encounters. On the other hand, the wider a wire is, the more the electricity can flow. Keep this in mind if you’re installing a compressor far away from the electrical connection point.

While these are good general tips to follow, you should always work with a professional electrical engineer to determine what your system can handle. The last thing you want is a new compressor that can’t be used in your current facility. If you have more questions on compressor electrical ratings, contact one of our experts.