Insulation Resistance Measurement Of The Electrical Installations - Amprobe MultiTest 1000 Manual Del Usuario

Check the continuity among:
a) Earth poles of all the plugs and earth collector or node.
b) Earth terminals of class I instruments (Boiler etc.) and earth collector or node.
c) Main external masses (water, gas pipes etc.) and earth collector or node.
d) Auxiliary external masses to the earth terminal.
ALLOWABLE VALUES
The standards CEI 64-8/6 do not give any indication of the maximum resistance values in
order to be able to declare a positive outcome of a continuity test.
The standard CEI 64-8/6 simply requires that the instrument in use warns the operator if
the test was not carried out with a current of at least 0.2 A and an open circuit voltage
ranging from 4 V to 24 V.
The resistance values can be calculated according to the sections and lengths of the
conductors under test. If the instrument detects values of some resistance the test can be
considered as passed.
11.2. INSULATION
INSTALLATIONS (250VDC, 500VDC, 1000VDC)
PURPOSE OF THE TEST
Check that the insulation resistance of the installation complies with the requirements of
standards CEI 64-8/6.
NOTE: This test is to be performed on an open circuit with all loads disconnected.
INSTALLATION PARTS TO BE CHECKED
a) Between each active conductor and the earth (the neutral conductor is considered an
active conductor except in the case of TN-C systems where it is considered part of the
earth (PEN). During this measurement all active conductors can be connected to each
other, in case the measurement result does not fall within the standard limits the test is
to be repeated for each single conductor.
b) Among active conductors. The standard CEI 64-8/6 recommends checking the
insulation among the active conductors when this is possible (ATTENTION).
ALLOWABLE VALUES
The values of test voltage and minimum insulation resistance are reported in the following
table (CEI64-8/6 Tab. 61A):
Rated circuit voltage (V)
SELV and PELV*
Up to 500 V included, except for the
above circuits.
Over 500 V
* In the new standards the terms SELV and PELV replace the old definitions "safety low
voltage" or "functional".
RESISTANCE MEASUREMENT
Test voltage (V)
250
500
1000
OF THE ELECTRICAL
Insulation resistance (MΩ)
≥0.250
≥0.500
≥1.000