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Topic Title: Ring circuit keeps tripping rcd on a split board.
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Created On: 05 August 2010 06:38 PM
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 05 August 2010 06:38 PM
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suzuki

Posts: 6
Joined: 05 August 2010

Hi, i am facing a bit of a challenge with a job i looked at.

There is a ring circuit on the ground floor of this house which keeps tripping the rcd. i have:
- Disconnected L-N-E of both legs at the fuseboard
- unplugged everything on the circuit.
- I have taken off all the sockets and done an IR test to the 1st point between L-N. reading OL with socket disconnected. i reconnected this socket and proceeded to do this until the 5th socket. i then recieved a reading of about 1.8M ohms. is this the problem somehow when the following note is taken into account.
- when reconnecting at the fuseboard as a radial up to this point it did
not trip.
- I then disconnected this leg and reconnected the other leg as a radial up to this point. no trip.
- I changed this socket with a new 1 and reconnected both legs of the ring at the fuseboard. Tripped. any ideas of what else needs to be done, changed or tested.
got to go back to the job on monday and would appreciate some advice before then. thanks
 22 August 2010 12:19 PM
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Avatar for Legh.
Legh

Posts: 3435
Joined: 17 December 2004

Originally posted by: suzuki

Hi, i am facing a bit of a challenge with a job i looked at.

There is a ring circuit on the ground floor of this house which keeps tripping the rcd. i have:


At what point did you realise that this problem existed ie were you informed by the client or was it after you changed the DB?

- Disconnected L-N-E of both legs at the fuseboard

- unplugged everything on the circuit.


RFC test end to end and then linked as suggested by GN3?

- I have taken off all the sockets and done an IR test to the 1st point between L-N. reading OL with socket disconnected. i reconnected this socket and proceeded to do this until the 5th socket. i then recieved a reading of about 1.8M ohms. is this the problem somehow when the following note is taken into account.


Cable damaged between skt 4 and 5?

- when reconnecting at the fuseboard as a radial up to this point it did not trip.

- I then disconnected this leg and reconnected the other leg as a radial up to this point. no trip.


IR test cable between skts 4 - 5

- I changed this socket with a new 1 and reconnected both legs of the ring at the fuseboard. Tripped. any ideas of what else needs to be done, changed or tested.

got to go back to the job on monday and would appreciate some advice before then. thanks


Try posting your query on the 'wiring regulations' forum you are more likely to get some pertinent replies



Legh

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http://www.leghrichardson.co.uk

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