Transient Overvoltage (HIOKI)


Instrument location : Factory, 3-phase 3-wire, 200V circuit


A transient overvoltage was detected in all events occurring several times during the measurement. Unfortunately, the cause of the transient could not be determined.

Analysis of transient waveform

  1. Occurred on all 3 phases (R-S, S-T, T-R) simultaneously
  2. Occurred twice in 1 cycle of the commercial waveform, and the interval between 2 events is 820μs
  3. The level is between 120V to 260V peak-to-peak
  4. The frequency is between 10kHz and 30kHz

Transient Overvoltage 1

Transient Overvoltage 2

Transient Overvoltage 3
Note : A threshold set at 1/2 of the waveform peak value is effective for detecting transient overvoltage. For example, set the threshold at 0.07kV for a 100Vrms circuit, and 0.14kV for a 200Vrms circuit.

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