UPDATE // PSI Power and Controls and Salient Power Systems have merged. Read More Here »
Subpage Banner Subpage Banner

back to blog

How to Choose the Correct Amperage for Your Transfer Switch?


Transfer Switches

eaton magnum manual transfer switchAt PSI Power & Controls, our dedication is to ensuring you get the best solutions and products possible to meet the electrical access and safety needs of your commercial business. Transfer switches are one of the most effective and sought after of our products, and are an integral part of ensuring your business gets fast, safe access to electrical power from your generator in the event of an emergency.

Because of their importance, ensuring you find the correct size transfer switch to suit your needs is vital. Incorrectly sizing your switch results in poor performance, if it will perform at all when paired with your generator system. To help you correctly choose, our experts have detailed this simple guide to sizing transfer switches.

To learn more about our automatic transfer switches and manual transfer switch products, be sure to visit our product guide!

What Is a Transfer Switch’s Size?

When the term size is used in regards to a transfer switch, the measurement in question is not actually the literal size of the device. Size is simply an easy term that denotes amperage, which is the measurement of electric current that the switch can safely and accurately handle.

When looking at transfer switches, you’ll likely see “amp ratings,” usually ranging from as low as 50, all the way up to the thousands. This shows the number of amps your transfer switch will operate with, and is what we would call its “size.” For example, a transfer switch that handles 200 amps, would be a size 200 transfer switch.

This information spans most safety and access devices, including tap boxes, motor starters, and both manual and automatic switches.

How Do I Size My Transfer Switch?

Sizing your transfer switch is actually a fairly simple process, depending on how much information is available to you. The shortest and fastest way is to simply match your transfer switch to your generator tap box, assuming you have one already installed. This makes sizing a quick and simple task, as if your tap box is 200, as will be your transfer switch.

Another way is to determine according to what you intend to power with your generator, but this is somewhat complex, and we would recommend seeking a certified electrician for accurate answers.

The surest method of sizing your switch is by matching it to your generator. Finding your generator’s load will tell you how powerful your transfer switch needs to be in order to perform effectively and safely. However having said all of this, the needs of any individual commercial business are somewhat complex, and always different. To find the ideal solutions for your business, we highly recommend consulting a certified electrical service professional, or speaking with your on-site service team.

PSI Power & Controls Offers Transfer Switches

PSI Power & Controls supplies a wide range of both automatic transfer switches and manual transfer switches to suit your commercial business’ specific needs! If you have questions or comments regarding our products, please feel free to contact our staff any time!

Contact Your Rep Today