METREL EurotestCOMBO MI 3125 User Manual

MI 3125 / BT EurotestCOMBO Measurements
44
5.5 Fault loop impedance and prospective fault current
Fault loop is a loop comprised by mains source, line wiring and PE return path to the
mains source. The instrument measures the impedance of the loop and calculates the
short circuit current. The measurement is covered by requirements of the EN 61557-3
standard.
See chapter 4.1 Function selection for
instructions on key functionality.
Figure 5.23: Fault loop impedance
Test parameters for fault loop impedance measurement
Test
Selection of fault loop impedance sub-function [Zloop, Zs rcd]
I test*
Selection of test current [Std, Low]
Fuse type
Selection of fuse type [---, NV, gG, B, C, K, D]
Fuse I
Rated current of selected fuse
Fuse T
Maximum breaking time of selected fuse
Lim
Minimum short circuit current for selected fuse.
*Applicable only in Zs rcd (some models)
See Appendix A for reference fuse data.
Circuits for measurement of fault loop impedance
Figure 5.24: Connection of plug commander and 3-wire test lead

METREL EurotestCOMBO MI 3125 Specifications

General

Brand	METREL
Model	EurotestCOMBO MI 3125
Category	Measuring Instruments
Language	English