Fluke 435 user manual Volts/Amps/Hertz

Volts/Amps/Hertz 8

Tips and Hints

Zoom. Allows you to expand or shrink the display vertically or horizontally to view details or to fit a complete graph within the screen area. Zoom and Cursor are operated by the arrow keys and explained in Chapter 19.

Offset and Span of the Trends are auto ranging for a good display in most cases, but they are adjustable when required. The adjustment menu is reached via the SETUP key and function key F3 - FUNCTION PREF. See Chapter 20, FUNCTION PREFerences.

Tips and Hints

Voltage and frequency should be close to the nominal values of for example 120 V, 230 V, 480 V, 60 Hz, or 50 Hz.

The voltages and currents in the Meter screen can e.g. be used to check if power applied to a 3-phase induction motor is in balance. Voltage unbalance causes high unbalanced currents in stator windings resulting in overheating and reduced motor life. Each of the phase voltages should not differ more than 1 % from the average of the three. Current unbalance should not exceed 10 %. In case of too high unbalance, use other measuring modes to further analyze the power system.

A Crest Factor close to 2.0 indicates high distortion. CF = 2.0 can e.g. be found if you measure the current drawn by rectifiers that only conduct at the sine wave top.

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