METREL MI 3122 Instruction Manual page 33

MI 3122 Smartec Z Line-Loop / RCD
Line to neutral
Figure 5.13: Examples of line impedance measurement result
Displayed results:
Z .............. Line impedance,
I ............ Prospective short-circuit current,
SC
Lim .......... Low limit prospective short-circuit current value or high limit line
impedance value for the UK version.
Prospective short circuit current is calculated as follows:
where:
Un ........ Nominal L-N or L1-L2 voltage (see table below),
ksc ....... Correction factor for Isc (see chapter 4.2.6 ).
Note:
High fluctuations of mains voltage can influence the measurement results (the noise

sign is displayed in the message field). In this case it is recommended to repeat
few measurements to check if the readings are stable.
UK version
Un

I
SC
U Input voltage range (L-N or L1-L2)
n
110 V (93 V  U
(185 V  U
230 V
400 V (321 V  U
Line to line

k
SC
Z
 134 V)
L-N
 266 V)
L-N
 485 V)
L-L
33
Line impedance