One of the most common questions we get from techs is about using a voltmeter to diagnose a high voltage circuit. It's especially tricky when a tech is used to working on a low-voltage or 120V circuit, where there is a clear “hot” side of the circuit and a clear “grounded” side of the circuit. […]

I used to call PTCR devices a "Soft Start". I was wrong.

Have you ever seen a low-voltage transformer like the one shown above? It has multiple input (primary) taps for a good reason. It is common to find three-phase and single-phase equipment rated to operate on both 240v and 208v power. That is because three-phase power can either be 208v leg to leg when the building […]