Benning IT 120 B 044102 Manual De Usuario

70

133 V

133 V

L1

L2

230 V

133 V

L3

230 V

230 V

Optional

high

impedance

N

 (Optional)

IMD

-  three-phase star connection, optionally delta connection
-  optional neutral conductor
-  single-phase connection is possible as well
-  different mains voltages (not only three phases 230 V as shown above)
-  The faulty connection of an arbitrary conductor to the protective conductor is considered to be 

the first fault and is admissible. However, the fault must be eliminated as rapidly as possible.

-  IEC 60364-4-41: The following monitoring devices and protective devices can be used in IT 

systems:

 

- 

insulation monitoring devices (IMDs),

 

- 

residual current monitors (RCMs),

 

- 

insulation fault detection systems,

 

- 

overcurrent protection,

 

- 

residual current protection devices (FI/RCD)

Note:
-  If a residual current protection device (FI/RCD) is used, the triggering of this device in case of a 

first fault due to capacitive leakage currents cannot be excluded.

The test procedures for IT systems slightly differ from the normal test procedures for TN/TT 
systems.

Before testing, the user has to select the IT system in the device. To know how to select the IT 
system, refer to chapter 4.5.1 „Selecting the Power Supply Network“. After having selected the IT 
system, the device can be used immediately. The selected IT system remains stored in the device 
even if the device is switched off.

The table below contains the functions of the BENNING IT 120 B as well as remarks concerning 
the compatibility with IT systems.