Fluke 434-II/435-II/437-II
Users Manual
11-4
Cursor. When the Cursor is on, the Trend values at the Cursor are displayed in the screen
header. Moving the Cursor off the left or right side of the screen brings the next of six
screens into the viewing area.
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 23.
Offset and Span are auto ranging for a good display in most cases. This is based upon
Nominal Voltage (Vnom) and Current range (A range). If desired, you can change Offset
and Span. The adjustment menu is reached via the SETUP key, F4 – MANUAL SETUP,
F1 - TREND SCALE. There are separate adjustments for PHASE and TOTAL (to be
selected with F3). See Chapter 24, MANUAL SETUP.
Tips and Hints
Power mode can be used to record apparent power (kVA) of a transformer over several
hours. Look at the Trend and find out if there are times that the transformer is overloaded.
You can transfer loads to other transformers, stagger the timing of loads, or if necessary
replace the transformer with a larger one.
Interpretation of Power Factor when measured at a device:
• PF = 0 to 1: not all supplied power is consumed, a certain amount of reactive power
is present. Current leads (capacitive load) or lags (inductive load).
• PF = 1: all supplied power is consumed by the device. Voltage and current are in
phase.
• PF = -1: device generates power. Current and voltage are in phase.
• PF = -1 to 0: device is generating power. Current leads or lags.
If you see negative power readings and you are connected to a load, check to make sure
the arrows on your current clamps are pointing towards the load.
Reactive power (var) is most often due to inductive loads such as motors, inductors, and
transformers. Installation of correction capacitors can correct for inductive var’s. Be sure
to check with a qualified engineer before adding PF-correction capacitors, especially if
you measure current harmonics in your system.
1.800.868.7495info@Fluke-Direct.ca
Fluke-Direct.ca
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