[EE]:: Earth Loop Fault Impedance testing - checking result

This question is published on Stack Exchange DIY here
https://diy.stackexchange.com/q/317178/34671
I've also sent a version to Megger but odds of reply are unknown.

This question relates to the use of a Megger MFT1825 meter but people
experienced in Earth Loop Fault Impedance testing may be able to advise.

I am conversant with the principles involved in Earth Loop Fault Impedance
testing, but not with the secret magic internal workings of this meter. I
have sent a message to Megger which may or may not produce results.

A Megger MFT1825 meter was used to (notionally) carry out an Earth Loop
Fault Impedance test. (Not by me).
The result appears incorrect and I suspect that the meter may have been
incorrectly used.
(The circuit was about 35 metres of 10 mm VIR or better cable, The
insulation was in good condition)

The test was carried out on a domestic property at the home's main
switchboard.
Connection was to Neutral and Phase only.
Meter dials were set to L-PE & Re-3P

Image of meter showing dial settings & reading.
https://i.sstatic.net/DaHgXXu4.png

This does not appear to be a valid setting in the MFT1825 manual - but MAY
be.
The manual shows settings of L-PE & 2P.
Here the only connections were Phase and Neutral.

The reading was
0.58 Ohm, 397 A with main house switch OFF.
0.64 Ohm, 358 A with main house switch ON.
< The *rise* in apparent impedance with eternal load may suggest a voltage
drop on transient load test.><May>.

I anticipate a reading around 0.2 Ohms or less.

<= 35m x 10mm Phase and Neutral , neutral screened with good condition
probably india rubber insulation.

The readings appear consistent with a mains voltage of ~~= 230 VAC.
Mains are nominal 230 VAC, 50 Hz.

Based on general knowledge of settings on meters of this type - or of this
particular meter
Can you please advise:

1. Is that a valid dial setting for Earth Loop Fault Impedance testing on a
live circuit with only P & N connected.

2. If not, does the reading give any indication of the expected result.

3. What dial setting or settings would be valid?



   Russell McMahon