GMC-I Messtechnik GmbH
13
Attention
!
!
The connector cable must be shaken back and forth, section by section over its
entire length, during measurement (for permanently installed devices only insofar as
the connector cable is accessible during repair, modification or testing).
Unrealistic, continuously changing measured values indicate poor contact, a damaged
protective conductor or a broken core in the probe cable (21) in the event that it has been
excessively stressed! If brief or continuous interruption of the protective conductor occurs
during the manual step of the continuity test, the limit value indicator at the
METRATESTER 5+ test instrument lights up and an acoustic warning signal is generated. In
such cases, the interruption must be repaired in a professional manner and measurement
must be repeated.
Measurement of protective conductor resistance is of course impossible for devices which
are not equipped with a protective conductor (e.g. protection class II and III devices).
6.2
Measuring Insulation Resistance
This test must be performed on all DUTs for which all insulation is checked during testing
without applying mains voltage (practically all DUTs without electrically actuated switches
and relays). If this is only possible after applying mains voltage, testing in accordance with
section 6.3.2/section 6.4.1 must be performed. If there is any doubt about performing
measurement with insulation voltage, for example at electronic devices, measurement must
also be performed in accordance with section 6.3.2/section 6.4.1.
It must be assured that all switches, thermostats etc. are closed!
Attention
!
!
Do not touch the instrument’s terminal contacts during insulation resistance
measurements!
If nothing has been connected to the terminal contacts, or if a resistive load component has
been connected for measurement, your body would be exposed to a current of approx.
1 mA at a voltage of 500 V. The resulting electrical shock is not life endangering. However,
the noticeable shock may lead to injury (e.g. resulting from a startled reaction etc.).
Attention
!
!
If measurement is performed at a capacitive object such as a long cable, it becomes
charged with up to approx. 500 V!
Touching such objects is life endangering!
In accordance with DIN VDE 0701-0702, L1, L2, L3 and N (short-circuited) are measured
against PE during this test (connection per section 5.2).
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Switch the DUT on in all functions.
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Set the NETZ-VDE switch to “VDE”.
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Set the measuring function selector switch (6) to the “20 MOhm” range.
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Read the measured value in MOhms at from the LCD panel, and compare it to
permissible values in accordance with DIN VDE 0701-0702.