A little while ago I had one of those immensely annoying – and unwinnable – arguments in an online forum with a guy I’d never met. You’d think the touchy topic was the wisdom of wearing a face mask (I ...

Here is a simple method for estimating the actual load on an electric motor without special equipment. But first, a word of caution: Some applications (e.g., a large forced draft fan) require more ...

The optimal size for a clutch or brake is determined by three things: Required torque, thermal horsepower per engagement, and average required thermal horsepower. Here, we'll discuss the first, ...

In a recent article, I wrote about step-motor system performance emphasizing key concepts that all engineers need to understand about this widely-used electro-magnetic-mechanical digital actuator. As ...

This is the second half of a two-part article discussing principles and application of the AC induction motors that provide motive power for most of the equipment HVACR engineers specify. In March, we ...

Selection of replacement motors is usually straightforward if the ratings are equivalent. Sometimes, however, a different type of motor is necessary or desirable. For success in these cases, it is ...