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Topic Title: "Double" ring main
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Created On: 05 July 2011 02:20 PM
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 05 July 2011 02:20 PM
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leckie

Posts: 1605
Joined: 21 November 2008

Looked at a consumer unit at found two ring mains sharing the same 32A mcb. Both tested OK but there were no spare ways so could not split up circuits without major expense.

Is this considered acceptable? If a PIR was being carried out would it be a code 4?

For the new EICR would it be a C3? Or perhaps just an additional observation.
 05 July 2011 02:29 PM
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AJJewsbury

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Joined: 13 August 2003

Provided it's not overloaded and presuming having one circuit rather than two isn't unreasonably inconvenient in the case of a fault, I can't think of a regulation that it would contravene.

(Except possibly the one about the c.p.c. of a ring having to be run as a ring, but I don't see any safety issue and if pushed I could argue it's two circuits fed from a common submain with a 32A MCB with individual circuit protective devices omitted as allowed by 433.3.1(i) - but I'd really have to be pushed to argue that!)

- Andy.
 05 July 2011 02:44 PM
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rogerbryant

Posts: 854
Joined: 19 July 2002

In theory you could join one end of the first ring to one end of the second ring and have a 'normal' ring final circuit. Would it increase the safety of the installation? I doubt it.

If both rings test out correctly I would suggest it is recorded as an observation. This comes back to many previous discusions about two radials originating from one OPD and are they one circuit or two.

Best regards

Roger
 05 July 2011 02:48 PM
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leckie

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Joined: 21 November 2008

The only thing I can think of in terms non-compliance is that the sockets are not divided into an adequate number of circuit, theres only the one circuit, which the ESC recommended a code 4 in a PIR. But were on EICR's now aren't we?
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