Motors make the HVAC world go ‘round — or, at the very least, in the HVAC business, they make the air go ‘round. And while some motors last for many years without any issues, others stop working ...

When you get the call, “The motor won’t start,” you’d best have a logical and systematic plan in place to approach the problem. “Easter egging” just doesn’t work unless you happen to be very lucky!

In Part 1 of this two-part series, we presented a 3-phase, 480VAC motor circuit with its associated controls (Figure). We stepped through a logical, systematic approach to troubleshoot the main power ...