Problem

The power supply of equipment is damaged.

Analysis

Some events were recorded during measurement. A switching waveform, which occurred during the power factor compensation capacitor switching, was detected. This kind of voltage waveform is recorded when a power factor compensation capacitor is installed in a facility. The switching noise comes through the low-voltage circuit without a filtering device.

Voltage Noise Waveform 1 (based on the voltage waveform distortion event)

In addition, a transient (impulse) voltage waveform is detected.  This kind of waveform occurs when the voltage waveform is affected by the start-up current of equipment.

Voltage Noise Waveform 2 (based on the voltage waveform distortion event)

Note : To detect intermittent noise, analyzing a voltage waveform distortion event is effective. The voltage waveform distortion event is set as the percentage of the voltage range. A setting from 10% to 15% is recommended.

Source : Guidebook for Power Quality Measurement, HIOKI E.E. Corporation