03/ 2020
BENNING IT 105 CH
23
8.5.1 Measurement with high test current (HIGH CURRENT)
Measuring the loop impedance Z
S
(L-PE) with a high testing current will trigger an upstream
RCD! If the RCD trips, “RCD” is indicated on the digital display
2
and measurement will
be interrupted.
- Select the desired function Z
S
/Z
I
(HIGH CURRENT)
G
with the rotary switch
1
.
- The symbols of the function keys F1
A
to F4
D
are briefly shown on the digital display
2
. You can
use the function keys F1 to F4
3
to make the following settings:
F1
F2
F3
F4
L-PE / L-N
–
–
AUTO
L-PE or L-N (F1):
It is possible to determine via the function key F1
3
, whether measurement shall be carried out between
L-PE (loop impedance Z
S
) or L-N (line impedance Z
I
).
AUTO start (F4):
With the Auto start function being enabled, measurement will be started 4 seconds after the BENNING IT 105
has been connected to the mains voltage. Press the function key F4
3
again to disable the function.
- Connect the measuring leads to the BENNING IT 105 as shown in figures 4, 5 or 6 and apply them to
the test object.
- Press the TEST key
4
to start the measurement.
- The main display
K
shows the loop impedance (Z
S
)/line impedance (Z
I
) and the secondary display
J
shows the prospective fault current (PFC)/short-circuit current (PSC).
Note:
For measuring the loop impedance Zs (L-PE) on three-phase loads without neutral conductor (e. g.
motors), the green measuring lead jack PE/L2
6
and the blue measuring lead jack N/L3
7
can be bridged
via the blue 4 mm adapter.
8.5.2 Measuring with a low testing current (NO-TRIP)
Measuring the loop impedance (Z
S
) L-PE with a low testing current normally will not trigger
an upstream RCD! However, existing fault currents in the installation might influence the
measurement. If the RCD trips, “RCD” is indicated on the digital display
2
and measure-
ment will be interrupted.
- Select the desired function Z
S
/Z
I
(NO TRIP)
H
with the rotary switch
1
.
- The symbols of the function keys F1
A
to F4
D
are briefly shown on the digital display
2
. You can
use the function keys F1 to F4
3
to make the following settings:
F1
F2
F3
F4
L-PE / L-N
–
–
AUTO
L-PE or L-N (F1):
When measuring with a low testing current, a test of the loop impedance (Z
S
) and of the line impedance
(Z
I
) will be carried out simultaneously. After the measurement has been carried out, the measuring result
can be called via the function key F1
3
.
AUTO start (F4):
With the Auto start function being enabled, measurement will be started 4 seconds after the BENNING IT 105
has been connected to the mains voltage. Press the function key F4
3
again to disable the function.
- Connect the measuring leads to the BENNING IT 105 as shown in figures 4, 5 or 6 and apply them to
the test object.
- Press the TEST key
4
to start the measurement.
- The main display
K
shows the loop impedance (Z
S
)/line impedance (Z
I
) and the secondary display
J
