User Manual

16 GMC-I Messtechnik GmbH
Note!
Testing the Measurement Cables
Initial testing should be performed by short-circuiting
the measurement cables using their test probes. The
instrument must display nearly 0 . A broken
measurement cable can be detected in this way.
Attention!
!
Do not touch the conductive ends of the test probes
when the instrument has been activated for the
measurement of insulation resistance.
You may otherwise be exposed to a current of
1.5 mA (limited in the measuring instrument), and
although this is not life endangering, the resulting
electrical shock is quite discernible.
Special Case: Capacitive Devices Under Test
If measurement is performed on a capacitive device under
test that includes components capable of storing electric
energy such as capacitors or long cables (> 100 m) of a
specific structure, the DUT may be charged to
approximately ± 600 V, depending upon the selected
nominal voltage.
Touching the device under test after measurement has
been performed may be life endangering in this case!
11.2 Insulation Resistance Measurement
Ð Press and hold the FUNC key until the display settles in, in
order to measure insulation resistance.
Attention!
!
The selected and displayed test voltage blinks during
measurement.
Attention: Contact hazard!
Current voltage at the device under test appears at the
interference or residual voltage display during measurement.
This value is slightly less than nominal voltage.
Insulation resistance measurement is ended by releasing the
FUNC key.
Auto-ranging is active during insulation resistance
measurement. Manual measuring range selection is not
possible.
Note!
The instrument’s storage batteries are rapidly
depleted during insulation resistance measurement.
Only hold the multifunction key depressed as long as
is actually necessary. The continuous measurement
described below should only be performed if
absolutely necessary.
Use NiMH storage batteries only.
Continuous Measurement
Ð Activation: Briefly press the multifunction key and the
MAN|AUTO key simultaneously. This is acknowledged with
an acoustic signal.
Ð Deactivation: Briefly press the multifunction key.
11.3 Ending the Measurement and Discharging
After insulation measurement has been completed (release
FUNC key), any remaining residual voltage is displayed which
may result from capacitance. As long as this capacitive
device under test is discharged via the internal resistor (2 M)
of the megohmmeter, contact to the device under test must
be maintained. The falling voltage value can be observed at
the interference or residual voltage display.
Do not disconnect the device under test until the voltage value has
dropped to below 25 V!
m
S+S–
M
R
ISO
: 10 k 3G
Measuring Range:
!
U (50 ... 500 V)