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 ...

In order for the solenoid point motor to throw the point we need to apply current briefly to an electromagnetic coil. A capacitor discharge unit greatly improves reliability in that it builds up and ...