Power quality monitoring technology: helping industrial equipment stay healthy | EDN


According to a recent study published by the Electric Power Research Institute (EPRI), large industrial facilities in the US lose over $100 billion every year due to power problems including power supply variations and voltage disturbances.  When the lights flicker at home, it’s an annoyance. But when power is disturbed at a factory, it can cause malfunction and early breakdown of expensive equipment.

1 Comment

  1. Tomi Engdahl says:

    Neutral woes

    noticed some of my lights were randomly flickering. Right away, I was concerned that we’d lost our 7.2 kV neutral again – something I wrote about in New house electric woes revisited.

    To better characterize what was going on, I hooked my scope up to the AC line. Yeah, that felt a bit scary, but the pre-worry was out of proportion to just actually doing it. It’s not like I’ve never scoped the line before…geez (I didn’t connect probe ground, instead relying on the scope’s AC ground).

    I then realized I’d get a lot more out of the experience by scoping both phases of the line

    The complementary waveforms scream “bad neutral!” (the neutral center-tap from my transformer secondary that is, unlike the missing HV neutral of my past woe).
    I walked the long 240V line (75m-ish) from the house to the transformer, and… TaDa. A small tree was resting against the line just steps away from the transformer. Though no damage was visible, the coincidence seemed too great.

    electric utility arrived a few days later (the day after I called in a panic because of extreme flickering, and reading peaks up to 150V – on a slow DMM!),



Leave a Comment

Your email address will not be published. Required fields are marked *