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Note :
VFD-ACV and the associated Hz are equipped with digital
low-pass filter (DSP), and are capable of handling VFD (Variable
Frequency Drives) signals for fundamental V & Hz readings.
It also improves ACV and Hz reading stability when being used in
most noisy electrical environments.
Line Frequency functions
Press the Hz push-button momentarily to toggle Hz function.
It is only available to Voltage and Current related ranges.
Input sensitivity varies automatically with the function range
selected while activating the Hz function. 6V function range has
the highest and the 1000V range has the lowest. When activated
under DCV, ACV or VFD-ACV voltage function, the trigger voltage
range will be displayed right before starting the Hz readings.
Press momentarily the RANGE button can manually select another
trigger voltage range (not available to current ranges). It is
recommended to first measure the signal voltage (or current) level
and activate Hz function in that range to get the most appropriate
trigger level. If the Hz reading becomes unstable, select lower
sensitivity to avoid electrical noise. If the reading shows zero,
select higher sensitivity.
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AutoV mode input impedance increases abruptly from initial
2.1kΩ to a few hundred kΩ's on high voltage hard signals. “LoZ”
displays on the LCD to remind the users of being in such low
impedance mode. Peak initial load current, while probing 1000VAC
for example, can be up to 673mA (1000V x 1.414 / 2.1kΩ),
decreasing abruptly to approx. 2.4mA (1000V x 1.414 /
580kΩ) within a fraction of a second. Do not use AutoV mode
on circuits that could be damaged by such low input impedance.
Instead, use rotary selector or high input impedance voltage
modes to minimize loading for such circuits.
WARNING :
ACV, DCV & VFD-ACV functions
Press the SELECT button momentarily to select the subject
functions in sequence. Last selection will be saved as power up
default for repeat measurement convenience.
