MI 3122 Smartec Z Line-Loop / RCD
Testing RCD
26
Loop resistance is indicative and calculated from Uc result (without additional proportional
factors) according to:
N
C
L
I
U
R
.
UK version
Figure 5.3: Example of contact voltage measurement results
Displayed results:
Uc ....... Contact voltage.
Rl ........ Fault loop resistance.
Rmax .. Maximum earth fault loop resistance value according to BS 7671.
5.1.2 Trip-out time (RCDt)
Trip-out time measurement verifies the sensitivity of the RCD at different residual currents.
Trip-out time measurement procedure
Select the
RCD
function using the function selector switch.
Set sub-function
RCDt.
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).
Figure 5.4: Example of trip-out time measurement results
Displayed results:
t .......... Trip-out time,
Uc ....... Contact voltage for rated I
N
.
