15
2. Press
to select L-PE.
3. Press
to select RE (resistance).
4. Press and release
. Wait for the test to complete.
• The primary (upper) display shows the loop impedance.
• The secondary (lower) display shows the earth resistance.
Line Impedance
Line impedance is source impedance measured between Line conductors or Line and
Neutral. This function allows the following tests:
• Line to Neutral loop impedance.
• Line to Line impedance in 3-phase systems.
• L-PE loop measurement. This is a way of making a high current, 2-wire loop
measurement. It cannot be used on circuits protected by RCDs because it will cause
them to trip.
• Prospective Short Circuit Current (PSC). PSC is the current that can potentially flow if
the phase conductor is shorted to the neutral conductor or another phase conductor.
The tester calculates the PSC current by dividing the measured mains voltage by the
line impedance.
Figure 9. Line Impedance Display
To measure line impedance:
1. Turn the rotary switch to the
position. The LCD indicates that the high current
loop mode is selected by displaying the
symbol.
2. Connect the red lead to the L (red) and the blue lead to the N (blue) terminals of the
tester.
3. Press F1 to select L-N.
4. Use the zero adapter to zero the test leads or the mains cord.
5. Press and hold
for more than two seconds until the ZERO annunciator appears.
The tester measures the lead resistance, stores the reading in memory, and subtracts it
from readings. The resistance value is saved even when the power is turned off so it is
unnecessary to repeat the operation each time you use the tester with the same test
leads or mains cord.
Note:
Be sure the batteries are in good charge condition before you zero the test leads.
