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SS004V2
3.1.4 No Trip Loop Testing
A brief press of the test button will initiate the loop test. Three socket test LED’s
will flash orange to indicate a loop measurement is being taken. The result will
then be displayed on the Fault loop results LED’s . For a guide to results please
see the below table.
FOR GUIDANCE ONLY: Refer to the IET Wiring standards BS 7671
< 1
Less than 1 Ohm: A good result and typical of a correctly wired
TN (PME) system.
< 2
Less than 2 Ohm: A result that would be worth pushing the plug
in and out to see if it is just tarnished socket contacts or
checking where the socket is located. If it is at the furthest point
of the end circuit a higher reading may be expected.
<100
Less than 100 Ohms: Now you must check the wiring system
being used. If it is a TT system (earth rod) then it is a good result
but if it is any other system this should cause concern and urgent
investigation is required.
< 200
Less than 200 Ohms: As above. Assuming it is a TT system most
codes of practice accept a Loop Test value of less than 200
Ohms for an earth rod for a system protected by a 30mA RCD
as being acceptable.
>200
There are very real problems with this system and urgent further
investigation is requited