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RCBO question

Posted: Tue Aug 19, 2008 10:49 pm
by GoNz0
Hi all, not all that new, but i finally need to ask something i cant find an answer to :)

so new account and here we go..

about to rewire my house and my sparky bro has told me to get RCBO's for the new consumer unit, so after a bit of searching i ended up buying contactums range to do the job as there a decent price.

its all arrived today and the RCBO's dont have an earth wire like most of the others i have seen, does this mean they wont be able to detect an earth leak ?

Re: RCBO question

Posted: Wed Aug 20, 2008 12:08 pm
by BLAKEY1963
[quote="GoNz0"]Hi all, not all that new, but i finally need to ask something i cant find an answer to :)

so new account and here we go..

about to rewire my house and my sparky bro has told me to get RCBO's for the new consumer unit, so after a bit of searching i ended up buying contactums range to do the job as there a decent price.

its all arrived today and the RCBO's dont have an earth wire like most of the others i have seen, does this mean they wont be able to detect an earth leak ?[/quote]

GONZO

Each product comes with manufactuers infomation sheet , and
contact information.
Any queries get in touch with them.

BLAKEY1963

Posted: Wed Aug 20, 2008 4:30 pm
by ericmark
I know I have seen an RCBO with an earth wire but not a clue why RCD's don't have them and neither do MCB's and today to find a v-ELCB would be hard they went out with the ark. I would be interested to find out why any RCBO requires an earth.
I bet Sparx has an answer?
Eric

Posted: Wed Aug 20, 2008 9:44 pm
by GoNz0
they didnt come with a data sheet, and contactums websites closed at the mo with only a link to there catologue.

a lot of googling did reveal that the earth is used for the test button to create an earth leak, if it doesnt have it then its using a resistor to test the circuit instead.

Posted: Wed Aug 20, 2008 10:30 pm
by speedygonzarlis
is it not because they have a neutral and as we all know the neutral is connected into the earth? theoretically its line and 2 earths!!

Posted: Wed Aug 20, 2008 11:59 pm
by GoNz0
its part of the test circuit "IF" the test circuit involves earth leak, in my case it doesnt

Posted: Thu Aug 21, 2008 12:32 am
by ericmark
It seems:-
1. The "functional earth" flying lead is the earth reference required in order to detect lost supply neutral; without this flying lead, the RCBO will not (adequately?) detect earth leakage unless the supply neutral is intact.
OK for a TN-C-S supply is the neutral is not intact then neither with the earth so I still can't see quite why it is there. Still looking!

Posted: Thu Aug 21, 2008 6:36 pm
by GoNz0
blinking moderation que is messing up my post placement :|