Insulation Testing - Iso-Tech IMT-3300 Bedienungsanleitung

b) Press the test button momentarily and release it. Check the "Ω"
symbol appears in the bottom right corner of the display.
c) Connect the test leads to the circuit to be tested.
d) Press the test button and the resistance value will appear on
the display.
e) Release the test button. The value will remain on the display for
approximately 3 seconds after the test button has been released.

5.2.3 Insulation testing

 Warning! Do not touch the circuit under test whilst the
insulation test is in progress.
 Warning! To ensure the circuit under test is fully
discharged after the test, always release the test button before
disconnecting the test leads from the circuit.
Note:Due to charging of the intrinsic capacitance of any circuit
under test, the insulation resistance value may not stabilise until
several seconds after the test button has been pressed. Wait for
the reading to stabilise before noting the value.
a) Set the function switch to the "Insulation" position.
b) Press the test button momentarily and release it. Check the "MΩ"
symbol appears in the bottom right corner of the display.
c) Connect the test leads to the circuit to be tested.
d) Press the test button and the insulation resistance value will
appear on the display.
e) Release the test button. The value will remain on the display
for approximately 3 seconds after the test button has been
released.
5.3 Loop impedance measurement and RCD testing
 Warning! This instrument must only be used on single-
phase circuits with a supply voltage of 230 Volts ac +10,
-15% phase to neutral or phase to earth. Do not connect the
instrument between phases on a 3-phase 415 Volts system.
 Warning! When conducting tests, particularly if using earth
spikes, do not touch any exposed metalwork. Currents flowing
during the test may generate hazardous voltages in any
earthed metalwork.
 Caution! Before carrying out tests on a protected circuit
which may trip an RCD, ensure any equipment connected to
the circuit will shut down in a safe manner and not cause a
hazard to the user.
Notes:
Ensure the tested RCD is returned to the original state after
the test.
The potential fields of other earth installations may influence
the measurement.
Special characteristics of RCDs of a particular design (for
example S- type) must be taken into consideration when
carrying out tests.
If a voltage exists between the protective conductor and
earth, it may influence the measurements.
If a voltage exists between neutral and earth, it may
influence the measurements, therefore, the connection
between neutral point of the distribution system and earth
should be checked before testing.
If the fault voltage (Uf) exceeds 50V AC, the display will
indicate 'VN-E-Hi', or if the input voltage is greater than 260V
the display will indicate 'VP-E Hi'. If the mains voltage is lower
than 100 Volts, "Lo" is shown on the display. In all cases,
testing is inhibited.
Equipment with capacitive or inductive characteristics
connected to the circuit protected by the RCD e.g. Motors,
capacitors or transformers, may cause a significant
increase of the measured trip time. Disconnect all such
equipment before testing the RCD.
If the symbol appears in the display, the internal test
resistor has become too hot and the automatic cut-out
circuit has operated to protect the instrument. Allow the
instrument to cool down before proceeding. When the
symbol disappears from the display, testing may continue.
The earth electrode resistance of a measuring circuit with a
probe shall not exceed 50Ω when measured at 500mA .
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