METREL EurotestXC MI 3152 - Page 113

MI 3152(H) EurotestXC (2,5 kV) Tests and measurements
112
Measurement procedure
 Enter the Z loop function.
 Set test parameters / limits.
 Connect test cable to the instrument.
 Connect test leads or Plug commander to the object under
test, see Figure 7.33.
 Start the measurement.
 Save results (optional).
Figure 7.34: Examples of Loop impedance measurement result
Measurement results / sub-results
Z
Loop impedance
Ipsc
Prospective fault current
Ulpe
Voltage L-PE
R
Resistance of loop impedance
XL
Reactance of loop impedance
Prospective fault current I
PSC
is calculated from measured impedance as follows:
Z
kU
I
SCN
PSC


where:
U
n
......... Nominal U
L-PE
voltage (see table below),
k
sc
........ Correction factor (Isc factor) for I
PSC
. Refer to chapter 4.6.5 Settings for more
information.
U
n
Input voltage range (L-PE)
110 V
(93 V  U
L-PE
 134 V)
230 V
(185 V  U
L-PE
 266 V)
Table 7.3: Relationship between Input voltage – U
L-PE
and nominal voltage – U
n
used for
calculation