6
Gossen Metrawatt GmbH
5.2
Measuring Insulation Resistance and Equivalent
Leakage Current
L1, L2, L3 and N (short-circuited) are measured
against PE during insulation testing.
5.3
Measuring Protective Conductor Resistance with
the Residual Current Method (except for SECUT
-
EST BASE / BASE10 / ST BASE / ST BASE10)
The DUT is placed into operation during residual
current measurement. The L1, L2 and L3 mains
lamps light up at the AT3-III E during this test.
This measurement may not be performed on safety
class I devices until after the protective conductor test
has been passed in accordance with chapter 5.1.
➭
Turn off the device under test.
➭
Select the I
L
-DI measurement setting at the
test instrument.
➭
The line contactor switches mains power to
the test outlets (1 – 4) at the AT3-III E. Signal
lamps L1, L2 and L3 indicate the presence of
line voltage.
➭
Now switch on the DUT (as described in
Contact current is measured by means of residual
current measurement for safety class II devices,
and safety class I devices with accessible con
-
ductive parts which are not connected to the pro
-
tective conductor. Contact all accessible conduc
-
tive parts at the device under test with the test
probe at the end of the probe cable form the test
instrument to this end.
These measurements must be performed with the
plug in both positions for DUTs with earthing con
-
tact plugs!
Note!
This test must be performed in accordance
with the specified test sequence.
Mains
power must be indicated by signal lamps L1, L2
and L3 (9) before switching the device under test
on.
The test outlets (1 – 4) are disconnected
from the mains by the safety shutdown func
-
tion included with the AT3-III E for devices
under test with fault currents of greater than
18 mA during measurement of protective
conductor current with residual current.
Mains power may be disconnected if the
AT3-III E is used in systems protected with
RCCBs rated less than 30 mA. Mains signal
lamps L1, L2 and L3 (9) go out. The function
LED (10) blinks.