MI 3122 Smartec Z Line-Loop / RCD
Testing RCD
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5.1.3 Trip-out current (RCD I)
A continuously rising residual current is intended for testing the threshold sensitivity for
RCD trip-out. The instrument increases the test current in small steps through appropriate
range as follows:
RCD type
Slope range
Waveform
Start value End value
AC
0.2
I
N
1.1
I
N
Sine
A (I
N
30 mA)
0.2
I
N
1.5
I
N
Pulsed
A (I
N
= 10 mA)
0.2
I
N
2.2
I
N
Maximum test current is I
(trip-out current) or end value in case the RCD didn’t trip-out.
Trip-out current measurement procedure
Select the
RCD
function using the function selector switch.
Set sub-function
RCD I
.
Set test
parameters
(if necessary).
Connect
test cable to the top of the instrument.
Connect
test leads to the item to be tested (see
figure 5.2
).
Press the
TEST
key to perform the measurement.
Store
the result by pressing the MEM key (optional).
Trip-out
After the RCD is turned on again
Figure 5.5: Trip-out current measurement result example
Displayed results:
I .......... Trip-out current,
Uci ...... Contact voltage at trip-out current I or end value in case the RCD didn’t trip,
t .......... Trip-out time.
5.1.4 RCD Autotest
RCD autotest function is intended to perform a complete RCD test (trip-out time at different
residual currents, trip-out current and contact voltage) in one set of automatic tests, guided
by the instrument.
Additional key:
HELP / DISPLAY
Toggles between top and bottom part of results field.
