How to Choose an Electric Motor: Application Criteria (Part 1)

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Video Transcript

Hi, this is Janette and I’m Joe with Groschopp.  Welcome to the second of ten videos in our series: “How to Choose an Electric Motor.”  In these next two videos, we’ll be discussing important application criteria. Part one will cover application constraints and part two will cover motor performance.

Each criterion we share is important to the motor selection process, and is typically unique to each application.

As you can see, there are a number of criteria to consider.  

Instead of addressing each of these individually, we’ll focus on the constraints and performance factors that are often overlooked but can be critical to motor design and the overall system solution. As a quick side note, we’ve provided a link below to download our application checklist.

Let’s start with the first constraint: input power.  You need to know what the available voltage, frequency, and current limits are and if a control will be needed to manage the motor within the application.

Pay close attention to the maximum allowable current early in your selection process. Often times it can be overlooked until the testing phase when failures occur.

To clarify, let’s look at a quick example.  

Medical patient lifts use standard electrical wall outlets as the power source. We generally need to limit the current to fifteen amps in order to meet UL requirements and not overload the electrical system.

When considering current, you should also look at efficiency. Current and efficiency can be changed by the style of gearbox, input power or other factors.  Our experience shows us that many applications need to maximize the output power from the motor as much as possible. One way to draw less current is by using a more efficient gearbox, such as a planetary reducer, over the less efficient worm gear design.

Now let’s talk about some environmental constraints, specifically particle ingress and temperature.

Most standard motors are built to operate in a clean, dry, room-temperature environment.  This is fine for many applications, but if your motor will be subject to temperature extremes, dust or water contamination, or corrosion, you may need to think about a motor with special construction.

We have two reference tools to help you with these environmental specifications.

The first is our ingress protection chart, or IP for short.

We’ve included a link to it in the description.  IP ratings are used to provide an industry-wide understanding of a motor’s protection against dust and water.

For example, a motor rated IP65 would be considered “dust tight” and “splash-proof.”

Our standard motors are built with either IP40 or IP44 ratings, but we can increase the protection as needed.

Our second reference tool is a chart for UL temperature class ratings.

This will give you a general idea of how hot the internal temperature of the motor can go before it will start to see damage.  For example, temperature class “B” means that the maximum temperature is 130 degrees Celsius, and that if this temperature is exceeded, the life of the motor will be shortened. This chart helps you determine what level of protection you need for your motor to run in extreme temperatures.

Here’s a rule of thumb, for every ten degrees Celsius that your application exceeds the maximum temperature rating, the motor life is cut in HALF!

Up next is part two of “application criteria” where we’ll discuss performance factors. You don’t want to miss it. Check out the links below for our application checklist, IP ratings chart and UL motor temperature chart. For more information about Groschopp or any of our products, check out our website at www.groschopp.com.

How to use the Motor Search Tool

Narrow your search by selecting motor type, gearbox, voltage, and phase options for your desired motor.

Select a dominant variable: choose one of the three parameters to narrow your search. The selected variable determines which slider bar you will be able to manually move.

Use the slider corresponding to your dominant variable to further narrow your motor selection. The other sliders will automatically move to show available ranges based on the range of your selected variable.

Results will upload as your search criteria changes. If you have any questions regarding your results or how to use the search tool, you can chat with us using the green tab on the left-hand side of your screen.

Note: Groschopp Universal motors are custom built to fit your application so no additional options are available to narrow the search. Selecting the Universal motor type will prompt a message taking you to the Universal product page.

Not sure what you need?

One of our team members would be happy to help. Contact us at 800-829-4135 or by email at sales@groschopp.com. You can also chat with us using the green tab on the left side of your screen.

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Universal Motors

Groschopp Universal motors are custom built to fit your application so no additional options are available to narrow the search. Standard frame sizes and motor features can be found on the Universal page.

go to Universal page