MARTINDALE ET4500 - Insulation Resistance Testing

Martindale ET4000 / ET4500 Measurements
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5.2 Insulation resistance
Insulation resistance measurements are performed to ensure safety against electric
shock through poor insulation. Typical applications are:
 insulation resistance between conductors of an installation,
 insulation resistance of non-conductive rooms (walls and floors),
 insulation resistance of ground cables and
 resistance of semi-conductive (antistatic) floors.
Four insulation resistance sub-functions are available:
 ISO L/E,
 ISO L/N,
 ISO L/L and
 ISO N/E.
The insulation resistance tests are carried out in the same way regardless which sub-
function is selected. However it is important to select the appropriate sub-function in
order to correctly classify the measurement when entering it into the required
verification documents (Electrical Installation Certificate, Periodic Inspection Report
etc.).
Please pay attention to the following warnings when performing insulation
measurements:
 Insulation resistance measurements must only be performed on de-energized
circuits and equipment.
 Do not touch the circuit or equipment under test during the measurement or
before it has fully discharged.
 When an insulation resistance measurement has been performed on a capacitive
circuit or equipment, automatic discharge may not be immediate. The warning
message and the actual voltage are displayed during discharge until the
voltage drops below 30 V.
 Do not connect the test terminals to an external voltage higher than 550 V (AC or
DC) or damage to the instrument may result.
See chapter 4.3 Function selection for instructions
on key functionality.
Figure 5.5: Insulation resistance
Test parameters for insulation resistance measurement
Test
Sub-function [ISO L/E, ISO L/N, ISO L/L, ISO N/E]
Uiso
Nominal test voltage [50 V, 100 V, 250 V, 500 V, 1000 V]
Limit
Setting range [OFF, 0.01 M - 200 M]