Measurement Of Insulation Resistance; Evaluating The Measurement Results - BEHA UNITEST ISO-compact Mode D'emploi

ATTENTION !
Remove the handle test probe, if required.
'
Contact UUT with instrument test probe. A beep sound
'
indicates the phase position.
Insulation Measurement
Prior to any resistance measurement, it has to be ensured
that resistance to be tested ist not live. Failure to comply with
this prescription can lead to serious operator injury or instru-
ment damage. Additionally, foreign voltages falsify the mea-
surement result.
During insulation measurement capacitive UUTs are charged
by the measurement voltage. The instrument automatically
discharges the UUT at the end of measurement. When
interrupting the measurement, a dangerous voltage may
persist at UUT. If a dangerous voltage is detected via
measurement function 3 (U/f), the UUT has to be discharged
by using a high-ohm resistance (not via short-circuit !).

4.3 Measurement of Insulation Resistance

' Remove hooked handle from instrument.
' Contact both test probes with UUT.
' Press button "Insulation Test" (5). The test voltages amounts
to 500 V for a current of 1 mA and remains preset during
button actioning. Upon release of the button the instruments
remains active for a further 5s approx. and then, switches off
automatically.
' Repeated actioning of the button "Insulation Test" (5) enables
selection of the appropriate measurement range.
The ISO-Compact is equipped with two insulation resistance
measurement ranges: 0...20 MV and 0...200 MV. They are selected
alternatively by enables the selection of the appropriate mea-
surement range during measurement.
ATTENTION !
The UUT may still carry a dangerous voltage charge after the
insulation measurement. Therefore, discharge the UUT by
carrying out a voltage measurement immediately after the
insulation measurement. Reverse polarity during voltage
measurement, if required, to achieve faster discharge. After
the discharge procedure check that all poles are voltage-free.

4.4 Evaluating the Measurement Results

The UNITEST ISO-Compact tests the insulation resistance at 500
V DC voltage. For a test voltage of 500 V, VDE specifies a minimum
insulation resistance of 500 kV.
The following table lists some minimum measurement values to
be achieved if a certain threshold value is required by considering
the instrument tolerance.
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