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ability that most other NCV detectors lack. However,
the detector’s lower sensitivity levels, which cover
common AC power voltages, also have great value,
for the following reason.
Merely detecting the presence of 120VAC near a
bundle of wires does not tell you which wire of the
bundle is the “hot” wire; any of the wires could be
activating the alarms. The NCV detector in the
CM660/700 can help you isolate the hot wire. This
application calls for turning down the sensitivity in
stages after the NCV detector senses voltage. As you
reduce sensitivity, at some stage only the energized
wire will produce a field strong enough to activate the
NCV’s alarms. In this way, the adjustable sensitivity of
the CM660/700’s NCV detector takes the guesswork
out of identifying the “hot” wire of a bundle.
By default, powering on the CM660/700 enables the
NCV function (indicated by the term NCV on the left
side of the LCD) and sets it to a sensitivity of 3. At this
level, the corresponding voltage detection range is 70
to 125VAC—optimum for detecting energized outlets
in the U.S.
To disable the NCV function or change its sensitivity
,
you must first power off the meter and then power it
back in special way—by pressing and holding the
FUNC/INRUSH
button while turning the rotary function
switch to a position other than
OFF
.
Powering on the meter in this way produces the
following display on the LCD.
