Loop/Line Impedance Measurements; Loop Impedance (Line To Protective Earth L-Pe) - Fluke 1662 User Manual

1662/1663/1664 FC
Users Manual

Loop/Line Impedance Measurements

Loop Impedance (Line to Protective Earth L-PE)

Loop impedance is source impedance measured between Line (L) and
Protective Earth (PE). You can determine the Prospective Earth Fault Current
(PEFC). PEFC is the current that could potentially flow if the phase conductor is
shorted to the protective earth conductor. The Tester calculates the PEFC as
the measured mains voltage divided by the loop impedance. The loop
impedance function applies a test current that flows to earth. If RCDs are
present in the circuit, they may trip. To avoid tripping, use the
on the rotary dial. The no trip test applies a special test that prevents RCDs in
the system from tripping. If you are certain no RCDs are in the circuit, you can
use the Z High-Current function for a faster, less noisy test.
I
If the L and N terminals are reversed, the Tester will auto-swap
them internally and continue the test. This condition is indicated
by arrows above or below the terminal indicator symbol (b).
If the Tester is configured for UK operation, L and N will not
auto-swap and the test stops.
Tips:

•
Use the
•
Preload conditions can cause the RCD to trip.
•
An RCD with a nominal fault current of 10 mA will trip.
•
To test loop impedance in a circuit with a 10 mA RCD, see the Applications
section.
34
position for loop measurements.
Note

function