LEM Saturn 100 Plus, Operating Instructions Manual, Page: 18 / 329

Measuring
16
3.5 Insulation Resistance (RISO)
This measuring mode serves for measuring insulation resistances up to 100 MOhm,
with automatic range selection. The measuring voltage used is a DC voltage of 500
V generated from the built-in batteries with a nominal current of 1 mA. For simple
measurement in single-phase systems, the power cord may be used, permitting
measurement of the insulation resistance between L – N – PE without replugging
the lines.
Note:
When measuring in systems with connected users, take care to disconnect the
users from the mains, at least for a single pole, e.g. by removing the built-in fuse or
turning off the mains switch. If after this the required insulation resistance values
are not met, the devices must be disconnected from the mains by all poles.
CAUTION! During measurement, voltages up to 520 V may occur,
which may be mortally dangerous in combination with high-
capacitance systems! Devices sensitive to over-voltages, e.g.
control circuits, microprocessor-controlled devices etc., should
be disconnected by all poles from the mains before measurement
for safety reasons.
Measuring Process:
L 1 = brown
L 2 = black
L 3 = purple
Instrument
Marker
L3 L2
L1
R
B
L2
L1
L3
N
PE (PEN)
L3
L2
L1
M
Instrument
Instrument
R
ISO
R
A