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GMC-I Messtechnik GmbH
6.3.4 RCCB Non-Trip Test with 50% I
N
for 2 Seconds Prior to Actual Tripping
In addition to the 30%-U I
N
measurement and the 100% I
N
trip test, a
non-trip test with 50% I
N
and a duration of 2 seconds can be performed
if desired. If the “½ I
N
ON” option has been selected, an appropriate icon
appears at the display. The icon is highlighted during the 50% test in
order to indicate execution.
If an RCCB is tripped during the 50% test, testing is interrupted and an
appropriate message appears at the display.
½ I
N
on or off can be
Display in the event of premature
selected in the vI
N
menu.
tripping of the RCCB
The selection as to whether or not the non-trip test is included in the
measurement remains unchanged after switching the instrument off.
6.4
Testing Special RCCBs
6.4.1 Systems with Selective RCCBs
Selective RCCBs are used in systems equipped with two series con-
nected RCCBs which are not triggered simultaneously in the event of
an error. These RCCBs have a time delayed tripping response and are
identified with the symbol
.
Measuring Method
The same measuring method is used as is the case for normal RCCBs
(see chapter 6.1, page 20, and 6.3.1, page 22).
If selective RCCBs are used, earthing resistance may only be half as great
as is the case for normal RCCBs. For this reason, the contact voltage
displayed at the instrument is twice the actual measured value.
➭
Select the limit value for allowable contact voltage, U
L
50V
or
U
L
25V
, in the respective TYPE sub-menu
.
S
S
S
