Source: Questline

Transients are brief voltage spikes that can originate inside or outside your facility and cause misoperation or shutdown of your equipment.

There are generally two types of voltage transients — low frequency (impulse) and high frequency (ringing).

Low-frequency transients are generally caused by things like power factor correction capacitors switching on across the line. Their frequencies are 400 to 600 hertz (Hz), compared to the normal 60 Hz, and the waveform peaks at 140% of peak voltage.

High-frequency transients are generally caused by things like lightning or inductive loads switching off. These frequencies are around 100 kilohertz (KHz), and the waveform peaks can be several thousand volts with short-circuit amperage.

One popular solution for transients are surge protection devices (SPDs). An SPD either clamps excess voltage to a specific value, diverts excess voltage to the safety ground or restricts propagation using a filter. The energy-diverting capability of an SPD is best expressed by its short-circuit current rating measured in amperes.

A better understanding of transients will help you stop power quality problems from interrupting your operations. Watch more information here.