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 ...

As an electric motor’s rotor turns in close proximity to the motor windings, a bucking voltage or back electromotive force (EMF) is generated. The back EMF (BEMF) generated across the start winding is ...

What is the normally closed SPST relay? The NC Normally-Closed SPST (Single Polse Single Throw) relay has an initial closed circuit state when no current is applied to its internal coil therefore it ...

Circuit breakers are manual switches that open under overload conditions. Circuit breakers discussed here are general-purpose types that meet the minimum Underwriters' Laboratories Inc. (UL) standards ...