25
of 150mA where the RCD should trip within 40ms, the tripping
time being shown on the display.
6
Press the phase selector switch to indicate 180˚in the display and
repeat the test.
7
Make sure to keep clear of earthed metal during the
operation of this tests.
8.5 Testing time delayed RCDs
RCDs with a built-in time delay are used to ensure discrimination, that is,
that the correct RCD operates first. Testing is carried out in accordance
with item 8.3 above, except that the displayed tripping times are likely to
be longer than those for a normal RCD. Since the maximum test time is
longer, there may be danger if earthed metal is touched during the test.
Make sure to keep clear of earthed metal during the operation of
this test.
Note:
If the RCD does not trip the tester will supply the test current for
a maximum of 2000ms on the x1/2 and x1 ranges. The fact that
the RCD has not tripped will be evident because the PN and PE
LEDs will still be on. The test current will flow for nominally
50mS on the x5 range.
8.6 Testing DC sensitive RCDs
The KT62 has a facility to test RCDs that are sensitive to DC fault currents.
Proceed as follows:
1
Set the RCD rated tripping current.
2
Set the function switch to DC test position.
3
The phase is fixed at 0˚.
4
Make sure that the P-E and P-N wiring check lamps are lit. If they
are not, disconnect the tester and check the wiring for a possible
fault.
5
If the lamps are lit, press the test button to apply rated tripping
current and the RCD should trip, the tripping time being shown
on the display.
Make sure to keep clear of earthed metal during the operation of
this test.
RCD tests
