Fluke 434 - Manual (Page 18)

Fluke 433/434
Users Manual
3-2
Measuring modes to investigate details
Phase voltages. Should be close to the nominal value. Voltage waveforms must be a sine
wave that is smooth and free from distortion. Use Scope Waveform to check the
waveform shape. Use Dips & Swells to record sudden voltage changes. Use Transients
mode to capture voltage anomalies.
Phase currents. Use Volts/Amps/Hertz and Dips & Swells to check current/voltage
relations. Use Inrush Current to record sudden current increases like motor inrush.
Crest Factor. A CF of 1.8 or higher means high waveform distortion. Use Scope
Waveform to see waveform distortion. Use Harmonics mode to identify harmonics and
THD (Total Harmonic Distortion).
Harmonics. Use Harmonics mode to check for voltage and current harmonics and THD
per phase. Use Trend to record harmonics over time.
Flicker. Use Flicker to check short and long term voltage flicker and related data per
phase. Use Trend to record these values over time.
Dips & Swells. Use Dips & Swells to record sudden voltage changes as short as half a
cycle.
Frequency. Should be close to nominal value. Frequency is normally very stable. Select
Volts/Amps/Hertz to display frequency. The course of frequency over time is recorded in
the Trend screen.
Unbalance. Each phase voltage should not differ more than 1 % from the average of the
three. Current unbalance should not exceed 10 %. Use Scope Phasor or Unbalance mode
to investigate unbalances.