METREL MI 3125 - Line Impedance and Prospective Short-Circuit Current

MI 3125 EurotestCOMBO Line impedance
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5.7 Line impedance and prospective short-circuit current
Line impedance is measured in loop comprising of mains voltage source and line wiring.
It is covered by requirements of the EN 61557-3 standard.
See chapter 4.1 Function selection for instructions on
key functionality.
Figure 5.27: Line impedance
Test parameters for line impedance measurement
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.
See Appendix A for reference fuse data.
Connections for measurement of line impedance
L1
L2
L3
N
PE
R E
Ro
LPEN
L
/
L
1
N
/
L
2
P
E
/
L
3
N/L2
L
/
L
1
PE/L3
Figure 5.28: Phase-neutral or phase-phase line impedance measurement – connection
of plug commander and universal test cable
Line impedance measurement procedure
 Select the Z-LINE function using the function selector switch.
 Select test parameters (optional).
 Connect test cable to the instrument.
 Connect test leads to the item to be tested (see figure 5.29).
 Press the TEST key to perform the measurement.