BENNING IT 115
Device description
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5.5 Loop impedance and prospective short-circuit current
The loop impedance is a complex AC current resistance within a fault loop (earth fault L-PE)
consisting of current source, external conductor and protective conductor. The installation tester
measures the impedance of the loop and calculates the short-circuit current. The measurement
complies with the requirements specified in the EN 61557-3 standard.
Key function as described in chapter
4.2 Function selector switch
Figure 5
.23
:
Loop impedance
Testing parameters
Test
Selects the loop impedance sub-function [
Zloop
,
Zsrcd
]
Fuse type
Selects the fuse type [---, gL/gG, B, C, K, D]
Nominal current
Nominal current
of the fuse
Tripping time
Maximum tripping time of the fuse
Lim (limiting
value)
Lower limit of the prospective short-circuit current
See Appendix A "Fuse table".
Connection plan
Figure 5
.24
:
Connection of the optional "Commander" test plug (044149)
and the three-wire test cable
