Ring main.

[JKMRK1]

Question I have is, is it ok to have x2 ring main circuits on one 32amp type B MCB??

If so does this meet the current regs.

TIA.

 

[DPG]

The thing is, you won't always be able to find a reg to say something is wrong. Otherwise where would it end? Do you have regulation 3.23.1.0.1 that says you cant have 18 RFCs in one MCB?

 

[Zerax]

...its Friday the pub is open.

Stop it !! You're such a tease...

 

[ipf]

The thing is, you won't always be able to find a reg to say something is wrong. Otherwise where would it end? Do you have regulation 3.23.1.0.1 that says you cant have 18 RFCs in one MCB?

...or seven 1.5 twin's in a rose.

 

[James]

The thing is, you won't always be able to find a reg to say something is wrong. Otherwise where would it end? Do you have regulation 3.23.1.0.1 that says you cant have 18 RFCs in one MCB?

manufacturors instructions.
terminal capacity of 32A mcb is 25 sqmm
18 rfc at 2.5mm is 90 sqmm
so yes it is against manufacturors instructions and outside of the specifications of the ocpd.

that's not to say that you cant find a breaker that will take all those cables.

I wouldn't fancy trying to terminate them correctly though!!

https://www.bgelectrical.uk/public/downloads/data-sheets/devices/circuit_protection_MCBs.pdf

 

[SparkyChick]

The thing is, you won't always be able to find a reg to say something is wrong. Otherwise where would it end? Do you have regulation 3.23.1.0.1 that says you cant have 18 RFCs in one MCB?

I absolutely 100% agree, which is why topics like this are good ones for discussion.

From a technical perspective I can find no reason the situation would breach the regulations but I just feel it's wrong.

For me, these are some points about why I think it's wrong....

It increases the inconvenience in the event of a fault or when works need to be carried out on one of the rings. It also raises some interesting questions about the testing and recording side of things.

Sure we can test each ring, but how do we record that? Separate lines on the cert or just use one line and record the worst case? If we do the latter we won't have records for a major section and thus we won't be able to determine if there has been any deterioration until perhaps there is a significant change.

What is the next spark going to assume about the installation? RFC + two spurs maybe, unless there is a note on the certificate. I think fault finding on it has the potential to be complete nightmare. Will they assume it was two spurs + a ring that have been bodged together by someone and then set about trying to 'fix' it?

 

[pc1966]

It increases the inconvenience in the event of a fault or when works need to be carried out on one of the rings. It also raises some interesting questions about the testing and recording side of things.

This is the sort of thing that is wrong with it, not the current capacity (as that is not different from a bigger single ring), but the fact it is hard to test and unexpected/unconventional for any future fault finding or repair work.

Nobody expects the Spanish ring final circuit! Among our methods are multiple connections and a fanatical...

 

[Mark Wright]

This is the sort of thing that is wrong with it, not the current capacity (as that is not different from a bigger single ring), but the fact it is hard to test and unexpected/unconventional for any future fault finding or repair work.

Nobody expects the Spanish ring final circuit! Among our methods are multiple connections and a fanatical...

Expats do it and Twin and Earth is illegal the main problem probably in Spain would be your insurance maybe an insurance company might not be happy with OPs arrangement again could they prove it is against any rules or unsafe.

In France where you have to follow local council rules you could get into quite a bit of trouble.

 

[radiohead]

SC I have stated my point of view, and although an interesting post I really have nothing more to say on the subject, you questioned the dangerous statement, which is your prerogative, I just think sticking two separate systems on one OCPD forming one circuit out of two systems is inherently dangerous, I have no other arguments to continue, what next a lighting system added to a RFC circuit OCPD? or vice versa?

I don't think you can leave it there Pete, I respect your point of view but you have to state exactly what you believe the danger is here, simply saying it's dangerous without giving reasons is not very helpful to those who don't have your experience and are wanting to understand.
Your point about a lighting system added to a RFC circuit is illogical as Spock might say, a lighting circuit is normally wired in 1.0 or 1.5mm cable, and connecting that directly to a 32a OCPD would be a breach of regulations and potentially dangerous because the cable would not be adequately protected against overcurrent. There is a sound reason for not doing so.

 

[JKMRK1]

I've carried out Continuity tests on all four conductors this evening to find it is 2 RFCs, both sets of circuit conductors have now been marked so they can be identified correctly. Also on closer inspection I've found an sorry looking 32amp breaker in amongst a load of other rubble which could of potentially been from the spare way in the Consumer? Orignally it looks as if these RFCs were both on there own MCB. Going forward I'll purchase a new breaker and seperate these two circuits to there own supply.

 

[7029 dave]

Just thinking the reasoning behind putting 2 RFC on one 32a , just maybe there was an interconnection between the 2 circuits, and some lazy so n so could not be bothered to fault find it.

 

[littlespark]

Can anyone else hear an echo?

 

[7029 dave]

Can anyone else hear an echo?

Did not see your post just looked back. lol

 

[James]

I've carried out Continuity tests on all four conductors this evening to find it is 2 RFCs, both sets of circuit conductors have now been marked so they can be identified correctly. Also on closer inspection I've found an sorry looking 32amp breaker in amongst a load of other rubble which could of potentially been from the spare way in the Consumer? Orignally it looks as if these RFCs were both on there own MCB. Going forward I'll purchase a new breaker and seperate these two circuits to there own supply.

I THINK I GUESSED RIGHT FOR ONCE!!

it could even be that originally it was 2 circuits.

failed mcb was removed and temporary supply taken from the one next to it.
late night tempory fix that never got finished off?

 

[7029 dave]

Gave you a funny

 

[SparkyChick]

It does not meat the regs BUT. if you exceed the loading I will be surprised but if you do the breaker will trip, ie doing its job.

@Ed Evans , as I've stated already in this thread I'm interested in peoples thought processes on things like this. How do you conclude that it's a breach of the regulations?