General Information About Rcd Tests - BEHA UNITEST TELARIS Fi/RCD Mode D'emploi

4. Proof regarding the low impedance connection of
equipotential bonding conductors in compliance
with Section 5.4 must be available.
Any test and measurement procedures in cir-
cuits equipped with residual current devices
should only be performed after having consult-
ed the operator terminals (data processing sys-
tems, material processing, motors, etc.).
Prior to testing, we recommend all loads are
switched off as they could falsify the measure-
ment result.
The protective earth must be free of external
voltage for the RCD test. However if an extra-
neous voltage is present, the instrument only
indicates the voltage VC having been generated
by the measurement. The measurement inter-
ruption caused by excess of UL by VC is only
generated by the actual voltage present be-
tween the neutral conductor (N) and the pro-
tective earth (PE).
Time-delayed residual current devices trip at
nominal residual current within 130...500ms,
for double nominal fault current within 60...200
ms. Such RCDs are implemented as main resid-
ual current protection devices (please refer to
IEC 61008-1) and are marked with the symbol
" S ".
The contact voltage represents the voltage pre-
sent during an insulation error between two si-
multaneously touchable components.
At a measuring circuit without probe, available
voltages between PE and earth can influence the
measurement.
Before using the N-conductor as probe check
that all neutral points have low ohm resistance
to the main neutral line. A available voltage of
the N conductor to the arth can influence the
measurement.

General Information about RCD Tests

The measuring function uses the N-conductor
as a probe. Check first the connection between
the neutral point of the distribution system and
earth before the test is started. A possible volt-
age between the N-conductor and earth may in-
fluence the measurements.
Leakage currents in current circuits following
the RC circuit breaker may have an influence
on the test as well as a voltage between pro-
tective conductor or neutral conductor and
ground.
Attached loads or operating supplies which
contains capacitors or circulating machines
can elongate the trip time.
Measurements may be influenced by potenti-
al fields of other grounding systems.
(FAT) measurements must be carried out in
compliance with the respectively valid stan-
dards and regulations.
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