Moving C/U

[mcgaw81]

I've been to look at an extension, wiring an extra bedroom with en-suite and dining-room, all straight forward. However, were they are making the new door way through to the dining-room is the suppliers fuse and the C/U:_|,

The DNO are going to move the cutout (free of charge as its moving less than 3m), but whats the best method of repositioningC/U? Thru crimping?

Any suggestions welcome

 

[Andy™]

lots of crimps... maybe a large enclosure in ceiling void to save insulating over each join

 

[mcgaw81]

Thats what i thought,

Thanks andy, again

 

[betty swollocks]

go for wago's, push fit connectors, put them in an enclosure, wago make their own but id go for something bigger and wack 'em all in one, if its in the ceiling make a little hatch above for later testing, mark floorboard as such

if you havnt used wagos they are simple, come in all sizes, push the conductor in and thats it, 2 rings, 2 lighting and cooker will be joined in no time at all, good solid connection too, if you're gonna crimp use a good quality crimping tool, it makes a huge difference

link for wago's

http://www.wagobox.com/shop

 

[Andy™]

dont forget wagos (0.75-2.5mm

 

[betty swollocks]

but even blue crimps are only rated at 16A ...... yet how many ringmains have they been used on?

 

[Andy™]

everywhere ive looked, there rated at 32A. Red at 25A and yellow at 48A

http://cpc.farnell.com/pro-power/cbbr7410/butt-splice-terminals-blue-32a/dp/CBBR7410?_requestid=440545

CPC code CBBR7410 if link doesnt work

 

[Apache]

but even blue crimps are only rated at 16A ...... yet how many ringmains have they been used on?

even if were - since it is a ring no point should exceed 16A anyways?

Is this not why we halve the MCB/RCBO rating on a radial vs ring?

 

[Andy™]

even if were - since it is a ring no point should exceed 16A anyways?

no. current in each leg of a ring isnt always the same. ohms law. if you use a socket next to mains board, there will be more current in the side to the mains, than around the house. putting a 24A connector n a cable that can take 27A is normally a bad idea, but in case of radials, it would normally be protected by a 20A breaker, so should be OK

 

[steptoe]

no. current in each leg of a ring isnt always the same. ohms law. if you use a socket next to mains board, there will be more current in the side to the mains, than around the house. putting a 24A connector n a cable that can take 27A is normally a bad idea, but in case of radials, it would normally be protected by a 20A breaker, so should be OK

but its OK to protect this cable with a 32a protective device????????

please explain why you find this acceptable/unacceptable(delete as appropriate),

I can be a bit thick sometimes.

 

[Andy™]

in a ring, in theory, the current should be split between both cables (but unlikely to be split 50/50) so little chance of overloading. for spurs, a double socket is only rated 13A so should never overload that cable (even if someone does plug in 26A, unless cable is in insulation etc, it should be OK).

If it wasnt OK, the regs would have banned rings by now

 

[steptoe]

in a ring, in theory, the current should be split between both cables (but unlikely to be split 50/50) so little chance of overloading. for spurs, a double socket is only rated 13A so should never overload that cable (even if someone does plug in 26A, unless cable is in insulation etc, it should be OK).If it wasnt OK, the regs would have banned rings by now

BS7671 neither has the ability to ban nor authorise anything whatsoever.

being competent gives you the legal right to make the decision on what is safe or dangerous, not being able to read a guide book.

you have said you shouldnt use a 24a connector in a cable rated at 27a, but by the same token you find it acceptable to protect this cable with a 32a protective device, I dont understand how you can differentiate this.

protective device <= cable <= design

 

[Robojin]

protective device <= cable <= design

Is this in correct order? should it not be cable <= p device <= design

in effect a ring is 2x27A = 54A, therefore 32A CB is acceptable, or did I miss read something in the thread ?:|

 

[Andy™]

the weakest part of a ring is the cable, only being rated at 27A compared to the breaker of 32A. since not all the current will flow through one leg of the ring, there isnt usually a problem. depending on where the load is connected, there could well be 27A (possibly more) flowing through one cable. obviously its not a good idea to add another weak spot (a 24A connector).

not really a problem using them in radials with a 20A (or lower) breaker

If there was a major problem, then 7671 could say rings cannot be used, unless its wired in 4mm or a 20A breaker (or maybe this could be a good market for 25A breakers?). in which case you might aswell make it a radial

 

[kme]

in a ring, in theory, the current should be split between both cables (but unlikely to be split 50/50) so little chance of overloading. for spurs, a double socket is only rated 13A so should never overload that cable (even if someone does plug in 26A, unless cable is in insulation etc, it should be OK).If it wasnt OK, the regs would have banned rings by now

Sorry Andy, but I`m with Steptoe on this one. Double sockets are rated 20A, not 13; as discussed in a previous thread (`pache?).

Technically, the load on the conductor can exceed the stated max in 7671, without adversely loading the 30/32A protective device.

Yes, I use ring circuits. Yes, I am aware of the inherent issues with them. However, I attempt to design my rings so that a socket outlet is not so near to the end of the ring as to cause this problem.

Informed choice is the phrase I would use. We know the issues, and either choose to fit one or not. Blindly stuffing ring circuits in everywhere, with S/O wherever you want `em will work, but may not be inherently safe; under certain operating parameters.

We have had a prior discussion of ring vs radial; so I don`t want to totally hijack the thread - but - this IS an important issue, and will keep cropping up

My opinion, for what its worth

KME

 

[Apache]

Sorry Andy, but I`m with Steptoe on this one. Double sockets are rated 20A, not 13; as discussed in a previous thread (`pache?).

http://www.talk.electricianforum.co.uk/showthread.php?t=1882

 

[Janice]

Going back to the original post, I agree with Betty Swollocks. As soon as I discovered Wago's I threw my crimper in the dustbin! Too many times trying to get the crimps on a really short cable, can't get the crimper in properly - no problem with Wago's.

And if you think that you might need to release a cable sometime in the future, there are lever-action ones available.

Cost of Wago's is easily covered by the time wasted making crimps that might not work first time.

J

 

[batty]

Going back to the original post, I agree with Betty Swollocks. As soon as I discovered Wago's I threw my crimper in the dustbin! Too many times trying to get the crimps on a really short cable, can't get the crimper in properly - no problem with Wago's.And if you think that you might need to release a cable sometime in the future, there are lever-action ones available.

Cost of Wago's is easily covered by the time wasted making crimps that might not work first time.

J

Janice the push fit ones you can get the cable out if you twist it have done it once or twice.

Batty

 

[Janice]

Janice the push fit ones you can get the cable out if you twist it have done it once or twice.Batty

But not easy to twist a short bit of T&E inside the confines of, say, a CU ]

J

 

[Janice]

Although, I must admit, I'm more used to working with singles in a factory-type environment.

J