MI 3108 EurotestPV
Measurements
– a.c. LV installations
43
5.3 Insulation resistance
The Insulation resistance measurement is performed in order to ensure safety against
electric shock through insulation. It is covered by the BS EN 61557-2 standard. Typical
applications are:
Insulation resistance between conductors of installation,
Insulation resistance of non-conductive rooms (walls and floors),
Insulation resistance of ground cables,
Resistance of semi-conductive (antistatic) floors.
Four Insulation resistance sub-functions are available:
ISO L/E,
ISO L/N
ISO L/L
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 classify the measurement to be correctly considered in verification documents
(Electrical Installation Certificate, Periodic Inspection Report etc.).
See chapter
4.2 Function selection
for instructions
on key functionality.
Figure 5.8: Insulation
resistance
Test parameters for insulation resistance measurement
Measurement
Subfunction
[ISO L/E, ISO L/N, ISO N/E, ISO L/L]
Uiso
Test voltage
[50 V, 100 V, 250 V, 500 V, 1000 V]
Limit
Minimum insulation resistance
[OFF, 0.01 M
÷ 200 M
]
Test circuits for insulation resistance
