METREL MI 3399, Инструкция с упражнениями

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Electrical Installation Safety Trainer AD 1 - MI 3399
81
2.4.2.2 Exercise No. 2.4-2: RCD trip-out time, current and contact
voltage measurements in an IT earthing system
Measuring procedure
1 To measure the contact voltage U
C
of a IT system select the RCD U
C
test.
2 To measure the trip-out time t
ΔN
of a IT system select the RCD t test.
3 To measure the trip-out current I
Δ
of a IT system select the RCD I test.
4 To perform all RCD measurements ( U
C
, t
ΔN
, I
Δ
) in one easy step select the RCD
Auto test.
5 Set the RCD test parameters (I
dN
, current type, selectivity and contact voltage limit)
by clicking in the bottom left dark grey corner and selecting the appropriate RCD
settings.
In this case we use a 30mA RCD so in an IT earthing system which has water
in the proximity. That is why the contact voltage limit must be set to 25 V.