TESTBOY TV 455 Benutzerhandbuch Seite 125

®
TV 450/455
5.6.1 Line impedance and prospective short circuit current
Circuits for measurement of line impedance
Ro R
E
Figure 5.28: Phase-neutral or phase-phase line impedance measurement – connection
Line impedance measurement procedure
Select the Z-LINE sub-function.
❑
Select test parameters (optional).
❑
Connect test cable to the instrument.
❑
Connect test leads to the item to be tested (see figure 5.28).
❑
Press the TEST key to perform the measurement.
❑
Store the result by pressing the MEM key.
❑
Line to neutral
Figure 5.29: 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
Prospective short circuit current is calculated as follows:
where:
of plug commander and 3-wire test lead
Un
=
I
SC
46
N PE
Line to line
version.

k
SC
Z
Line impedance
L1
L2
L3
N
PE
L