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Posted By Topic: RCD tripping when doing the ELFI test

Nov 19 2013 22:07

Unfortunately I do not have a non tripping RCD tester when doing my EFLI test i.e. if there is an RCD in the circuit it trips when doing the EFLI test.
Now if I can not get the reading for EFLI does the mere fact that the RCD tripped deem the circuit safe?
Any guidance would be appreciated.

Nov 19 2013 22:20

you do not need to do ELFI tests on RCD protected circuits.

Nov 19 2013 22:25 (notes) If an RCD operates during the test, the test result is considered satisfactory.

Nov 20 2013 07:00

It is not as satisfying though. I\'m always intrigued to know what the fault loop impedance is going to be, rather than a blinking \"trip\" message.

Nov 20 2013 07:53

Sometimes do want to get an ELFI reading on RCD protected sockets so have an adapter that transposes E & N.
Obviously this does not test the subcircuit PEC but is indicative of what result you would get on the PEC assuming it\'s the same size, all connections are good etc.

Have used this as a quick starting point for tracing a fault that turned out to be a bad neutral connection somewhere down the street.
Also a useful test of subcircuit P & N when a customer tells you there\'s something \'wrong\' with a socket because the second $10 Warehouse toaster in a month has burnt out when plugged into that socket.

Nov 20 2013 09:11

Lol, loop testing a circuit with an RCD on it. Anyone that know the correct function of an RCD AND the correct function of a loop tester will know that the two can never work together.

Nov 20 2013 11:23

They can and do work together if the current for checking the loop resistance is less than the trip current of the rcd. Testers have a setting to test at 15mA.

Nov 20 2013 12:38

this is where one of the slightly expensive meters some people complain about come in very handy. The tester I have doesnt trip the RCD and it is very informative to see the readings for the different circuits and the installation.