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 ...

A variable frequency drive (VFD) fails to vary the discharge-air fan speed. A motor overheats and fails prematurely. Programmable controls that generally operate without issue suddenly experience ...

Branch circuits are undoubtedly the most commonly installed circuits in both residential and non-residential applications. And, since they supply the equipment that utilizes the electricity, they are ...

Let’s face it: Diagnosing electric problems is a pain, to say the least. You can get far with a test light and your trusty digital multimeter, but you still might end up just throwing parts at the ...

We may receive a commission on purchases made from links. When undertaking DIY electrical projects at home, safety should always come first. Whether you're adding a dimmer switch, installing a new ...

Transmitter power is not the sole issue, but rather a combination of power and proximity. The lowly cell phone a few inches away may cause more problems than the broadcast transmitter a mile away. The ...

Relays usually are driven using optocouplers, which offer isolation between analog and digital grounds to ensure that switching currents in the relay coils do not affect the noise margin of the ...