Video Links

• Application Checklist

Video Transcripts

Hello this is Joe and Janette  with Groschopp and welcome to the third video in our series on “How to Choose an Electric Motor”. This is also part two of our discussion on application criteria. In the previous video we discussed challenges an application may present, specifically input power and environmental conditions. Now we’re moving on to performance criteria.

These are what we call “Motor Specs.” It seems obvious, but we like to remind our customers to always consider the maximum size and weight of motor their application will allow, and to know what kind of life expectancy the motor will need to have. Duty cycle criteria, whether the motor is running periodically or continually, are key to determining the life expectancy of the motor.

Let’s take a quick look at a side topic: noise. Noise is a complicated issue.  Decibel readings measure all frequencies the same way, but our ears don’t hear them all the same. This means we can hear two motors measuring the same decibels differently. Also, just measuring the decibels, of a motor doesn’t include some of the fundamentals you want to know about what type of noise is good or bad.  When you think about specifying for noise, it should include considerations about loudness and/or other features of noise that are of interest.

Now back to our final criteria: the motor performance variable.  In other words, what do you want the motor to do?

We’ve broken this down into three parameters: speed and torque, start or stall torque, and duty cycle.  It’s important to note that these parameters are co-dependent upon each other.  You should always look at them together to determine the best motor for your application.

Take duty cycle, it can have a significant impact on the motor size. If your application calls for the motor to run periodically, like in a security gate, the shorter operating times allow a smaller motor to put out as much power within the short time as a larger motor would running continuously. This is because the off-time for the intermittent duty motor allows excess heat to be released.

In summary, as a designer, looking to optimize the motor in your application, you can devote special attention to the rating and operating characteristics of any motor design.

This is why we encourage you to map out and prioritize your Application criteria before you begin the selection and customization process.

If you use this checklist to collect your application data and rank each item by priority for your application, you’ll have some direction as you go forward with motor selection and design.

While these may not be the only pieces of the puzzle, our decades of experience assures you that you can cover the majority of application considerations by following this list.

Before we wrap up, let’s quickly discuss the elephants in the room: price, quality and delivery.  We all know how important these factors are, but they are not included within our application checklist. We chose to focus on selecting the best motor from an overall performance standpoint.

From our experience, it’s best to review the issues of price, quality and delivery early in the design process, and then to revisit them in-depth during the vendor selection process, once a motor is selected.

Don’t go anywhere as we begin our discussion of Motor Types in the next four videos. First up: Universal Motors. Remember to check out the links below for the Application Checklist. For more information about Groschopp or any of our products, check out our website at www.groschopp.com.