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What is a new circuit under Part P regulations?

Postby ericmark » Thu Jul 04, 2013 1:19 pm

This has been talked about at length. The IET defines a "circuit" but not a "New Circuit" I would personally consider a new circuits as:-

A circuit for which there is no previous record in the schedule of test results.

However under the 17th Edition 314.1 made it very apparent that the RCD was part of the whole process of splitting every installation into circuits. We test and document the results for the RCD's in a modern consumer unit and this leaves us with a grey area. Where the 2 RCD consumer unit is used would my definition allow one to fit and use a new MCB to feed something not previously used?

Since form 4 does not allow one to group circuits which are all fed from the same RCD but you have to multi-enter the same results using the IET form 4 it would seem my definition would work. But are all forms made that was. Scheme members use different forms so what do the members of this forum think?
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Postby proptech » Mon Jul 08, 2013 9:53 pm

Hi ericmark
I was hoping another member would pick this one up. But if I can add my very simplistic thoughts, maybe not quite the answer you wanted.
I would say, any wiring that requires connecting to the CU, anything else could be considered and alteration.
I did say simplistic !

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Postby ericmark » Wed Jul 10, 2013 12:43 am

My son also came out with simple answer anything requiring an installation certificate is new circuit if a minor works then it's not.

However it would seem there are exceptions to these simple definitions as a spur taken from a ring can be connected at the consumer unit so not a new circuit but does involve work within the consumer unit.

With scheme members the £10 required to notify is nothing so scheme members are not worried but at £250 it's a very different story and clearly anyone who is likely to have to pay out that sort of cash will be looking for ways out.

The Welsh Part P lists what you can do but English now lists what you can't do which makes new circuit and consumer unit definitions very important. I have seen it said where a distribution unit is not at the origin of supply it's not a consumer unit so with for example a outbuilding it would be regarded the same as fitting a series of FCU's.

Reading IET regulations fitting a FCU supplying a series of sockets is a new circuit but it has been not regarded as a new circuits as far as Part P goes which means we can't use the IET definition.

As we start to look as work which could be done it becomes hard to work out what the law would require. For example you find an installation where the ring is broken and you can't find where so easy cure would be to swap the B32 for two B20 MCB's but the circuits already existed and the non registered electrician clearly does not want to pay the LABC fees. He has created two circuits from one but neither is "New".

How ever much we think it should be registered to show where it says that is required would be hard.

Even before new rules I did not see one case of where A1 work had been done and the guy doing the work did not claim be be a member of a scheme the simple fact that Part P was not complied with resulting in a court case. All the court cases reported either there was sub-standard work or some one claimed to be scheme member when they were not.

So if I was for example fitting a kitchen and I swapped the cooker MCB for the largest that would fit the consumer unit plus renewed the cable for 16mm SWA then used it to feed a kitchen distribution units with 4 RCBO's then one would naturally say that's a new circuit. But is it. The circuit already existed it's just been up graded.

So fitting a hob and oven instead of a stand alone with two separate supplies instead of one clearly new circuit lump them together on same MCB and it's not which will encourage people not to split into two separate supplies.

Of course the LABC was told also to review their charges so maybe the charges will drop to a point that it's not worth taking a chance. It was the charges that caused all the problems not the Part P.

So waiting to see how much charges drop.
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