Benning IT 105 CH Operating Manual page 29

8.5.1 Measurement with high test current (HIGH CURRENT)
Measuring the loop impedance Z

RCD! If the RCD trips, "RCD" is indicated on the digital display 2 and measurement will
be interrupted.
- Select the desired function Z
- 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
L-PE / L-N
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
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
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
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
- 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
L-PE / L-N
L-PE or L-N (F1):
When measuring with a low testing current, a test of the loop impedance (Z
(Z ) will be carried out simultaneously. After the measurement has been carried out, the measuring result
I
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
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(L-PE) with a high testing current will trigger an upstream
S
/Z (HIGH CURRENT) G with the rotary switch 1 .
S I
F2
–
) or L-N (line impedance Z
S
) L-PE with a low testing current normally will not trigger
S
/Z (NO TRIP) H with the rotary switch 1 .
S I
F2
–
BENNING IT 105 CH
F3
–
).
I
)/line impedance (Z
S
F3
–
)/line impedance (Z
S
F4
AUTO
) and the secondary display J
I
F4
AUTO
) and of the line impedance
S
) and the secondary display J
I

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