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GMC-I Messtechnik GmbH
8.1
Measurements with Suppression of RCD Tripping
8.1.1
Measurement with Positive Half-Waves (only PROFI
TEST
M
TECH
)
Measurement by means of half-waves plus DC makes it possible
to measure loop impedance in systems which are equipped with
RCCBs.
Select the Measuring Function
Set Parameters
* Parameters which are only used for report generation and do not
influence the measurement
Settings, I
K
Calculation
Short-circuit current I
K
is used to test shutdown by means of an
overcurrent protective device. In order for an overcurrent protec-
tive device to be tripped on time, short-circuit current I
K
must be
greater than tripping current Ia (see table in section ). The variants
which can be selected with the “Limits” key have the following
meanings:
I
K
: Ia
The measured value displayed for Z
L-PE
is used with-
out any correction to calculate I
K
.
I
K
: Ia+
% The measured value displayed for Z
L-PE
is corrected
by an amount equal to the test instrument’s measuring
uncertainty in order to calculate I
K
.
I
K
: 2/3 Z In order to calculate I
K
, the measured value displayed
for Z
L-PE
is corrected by an amount corresponding to
all possible deviations (these are defined in detail by
VDE 0100, part 600, as Z
s(m)
2/3 x U
0
/Ia).
Semiautomatic Measurement in Multi-Pole Systems
* See section 5.8 regarding AUTO parameter.
Start Measurement
Z
L-PE
Nominal current:
2... 160 A
Tripping characteristics:
B/E,C,D,K
Cross-section*:
1.5 ... 70 sq. mm
Cable types*:
NY..., H03... - H07...
Number of wires*:
2 ... 10-strand
Sine
Waveform:
15 mA sinusoidal
Positive half-waves
for 5 RCD nominal currents
Limit Value
:
I
K
< Limit Value
U
L
R
L
Measurements between
Lx-PE / N-PE / Lx-N / Lx-Ly / AUTO*
2-pole measurement
(selection only relevant for report
where x, y = 1, 2, 3
generation):
