Measuring
23
Read measured value, contact voltage „U
L
“. Repeated pressing of key l
Display“ brings up the loop resistance „R
S
“ or, if a probe is used, the earth/ground-
connection resistance „R
A
“, the tripping time „t
A
“ (not for measurement without
tripping) the tripping current „I
A
“ (for measurement with increasing test current) and
then again „U
L
“ into the display.
For another measurement press key
k „Start“.
To return to the original mode RCD-Measurement for displaying the mains voltage
„U
L-PE
“, turn the central selector.
Note:
For very accurate measurements of low loop or earth/ground-connection
resistances (below 1 Ohm), measuring-lead zero compensation may be performed
as per section 3.10.
Error Messages:
Flashing symbols on the display generally signify illegal conditions or errors, for
further information see section 3.11 „Display hints“.
CAUTION! To be certain that the fault current-protection circuit is operative, the
measurement must be effected at the first measuring point (outlet, device…) of
each FI current circuit with tripping of the FI-Circuit breaker! Testing without tripping
is only permitted for all measuring points connected in parallel.
When testing three-phase fault-current-protection circuits, each phase (L
1.
L
2
L
3
)
must be checked with respect to protective wire to ensure that all phases are
properly connected to the FI circuit breaker.
Fluctuations of measured value:
If, in case of several measurements, large differences occur between the measured
values, the reason is a mains voltage subject to major fluctuations.
The remedy is a measurement with probe, as described below.
Measurement with probe:
For measurements with probe, connect as per Figure; additionally put the included
leas
(25 m) into the sonde jack
q PROBE „Sonde“. The text „Sonde“ appears on the
display. Connect the free end of the probe measuring lead to earth/ground by using
the included earth/ground rod.
When measuring with probe take care that the probe is placed outside any voltage
funnels; i.e., keep a distance of approx. 20 m from the effective earth/ground
connections (see Connecting Diagram). To check, perform a measurement,
remembering the measured value; reposition probe and repeat measurement. If the
measured value remains unchanged, the distance of the probe from the
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