Справочник Пользователя для Benning IT 120 B 044102

74

BS7671

If an integrated protection against electrical accidents is required, but no safety extra-low voltage 

is used, it is necessary to use specific power supply networks. For this purpose, it is possible to
use power supply networks with lower voltage and earthing.
For a nominal voltage of 110 V, two options are possible:

55 V

55 V

PE

L1

L2

110 V

63 V

63 V

L1

L2

110 V

63 V

L3

110 V

110 V

-   single-phase with center tap, connected 

to the protective conductor (i.e. 2 x 55 V)

-   three-phase star connection with center tap, con-

nected to the protective conductor (i.e. 3 x 63 V)

-  no neutral conductor

-  no neutral conductor

Before testing, the user has to select the power supply network with lower voltage in the device. To 
know how to select the power supply network with lower voltage, refer to chapter 4.4.1 „Settings 
of the Power Supply Network“. After having selected the power supply network with lower voltage, 
the device can be used immediately. The selected power supply network remains stored in the de-
vice even if the device is switched off.

The table below lists the functions of the BENNING IT 120 B intended for testing and measuring of 
power supply networks. It also contains remarks on compatibility with regard to power supply net-
works with lower voltage.

R low-Ω

independent of the selected power supply network

continuity test

independent of the selected power supply network

line resistance

resistance RL1-L2.

prospective short-circuit current

I

PSC

 for U

L1-L2

 = 110 V