Cable leaving house to underground.

hard-work said:

I was a simple question. You even understood it, you wrote so. Then noise enters wanting know my shoe size, not understanding simple questions, or other irrelevant tripe coming in like the recent insertion.

What gobblegook? You answered differently to EFLImpudence. Which is the gobblegook, your answer or his?

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Yes I understood what you asked but now I'm going to ask 'Why you asked the question'? as the meaning of it still hasn't surfaced. I'll add to that by saying that not all questions have a yes/no answer, 'it depends' frequently crops up in the electrical environment.

I haven't reread the thread for this so perhaps you could point me directly to how I've contradicted EFL.

I asked a specific question and received answers, like I was wondering what question they were reading. One clearly could not understand the question. Anyhow that was cleared and it expanded to the size of an mcb on a ring spur (off a j box) that protects the spur cable. e.g., was given of an outbuilding or garage with a small sub CU (common setup). You say a 16A mcb, EFLImpudence does not specify the size as long as the spur cable is protected.

Instead of slagging people off who are trying to help for free whey don't you pay a professional for their advice?

Couldn't 4mm2 cable be used from the house from a socket DIRECTLY on the ring to the shed, to eliminate the 13A fuse?

The sockets in the shed could also be in 4mm2, meaning only a 3A-5A fuse needed in some form for the lights?

Or am I talking bolllocks?

PS, no wonder they call you Hard-work.

matlob said:

Instead of slagging people off who are trying to help for free whey don't you pay a professional for their advice?

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Best you read the thread from the beginning before you mouth off.

hard-work said:

I asked a specific question and received answer like I was wondering what question they were reading. One clearly could not understand the question. Anyhow that was cleared and it expanded to the size of an mcb on a ring spur (off a j box) that protects the spur cable. e.g., was given of an outbuilding or garage with a small sub CU (common setup). You say a 16A mcb, EFLImpudence does not specify the size as long as the spur cable is protected.

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Lets not get ahead of things here, first of all a sub CU fed by a FCU is not a common set-up, especially off a RFC. In fact I don't recall ever seeing it other than when the feed has changed for some reason or the building was prewired such as a Portacabin. To put it bluntly it is generally a complete waste of effort and money as no additional protection is offered [with caveats].

I predict that EFL didn't give a definitative value as there has been nowhere near enough information provided by you to do so, I simply offered the maximum permissable.
The RFC [originally called ringmain] and BS1362 & BS1363 were created for each other and the original maximum load was 13A but now the next standard sized MCB has become acceptable.

What you really have to learn is the amount of information that is now required in electrical design, in the old days it was easy: 15A socket, 15A fusewire & 7/0.029 etc. It aint like that now.

Your OP is very much akin to 'What flavour are red sweets?' So when you don't get the answer you want to hear don't complain, when these very experienced people ask for more information it means you haven't given enough. I will reiterate that and say I've witnessed a number of your questions where you have not given the needed information.

So please, for all of our sanity, stop complaining. If this is not plain enough for you the next answer will be.

sparkwright said:

Couldn't 4mm2 cable be used from the house from a socket DIRECTLY on the ring to the shed, to eliminate the 13A fuse?

The sockets in the shed could also be in 4mm2, meaning only a 3A-5A fuse needed in some form for the lights?

Or am I talking bolllocks?

PS, no wonder they call you Hard-work.

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Quite simple what is under discussion. Not rocket science. But a lot are hard work, for something so common.

A 2.5mm ring, then have a 4mm spur off that? Then have one socket off that?
Interesting. 4mm takes a max of 37A so the 32A fuse of the ring will protect that. But something tells me that is not quite right.

hard-work said:

Quite simple what is under discussion. Not rocket science. But a lot are hard work, for something so common.

A 2.5mm ring, then have a 4mm spur off that? Then have one socket off that?
Interesting. 4mm takes a max of 37A so the 32A fuse of the ring will protect that. But something tells me that is not quite right.

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Absolutely not right, it is way outside of the regs and the special arrangements for a RFC. Dont get complacent just because it is so common.

SUNRAY said:

Lets not get ahead of things here, first of all a sub CU fed by a FCU is not a common set-up, especially off a RFC. In fact I don't recall ever seeing it other than when the feed has changed for some reason or the building was prewired such as a Portacabin. To put it bluntly it is generally a complete waste of effort and money as no additional protection is offered [with caveats].

I predict that EFL didn't give a definitative value as there has been nowhere near enough information provided by you to do so, I simply offered the maximum permissable.
The RFC [originally called ringmain] and BS1362 & BS1363 were created for each other and the original maximum load was 13A but now the next standard sized MCB has become acceptable.

What you really have to learn is the amount of information that is now required in electrical design, in the old days it was easy: 15A socket, 15A fusewire & 7/0.029 etc. It aint like that now.

Your OP is very much akin to 'What flavour are red sweets?' So when you don't get the answer you want to hear don't complain, when these very experienced people ask for more information it means you haven't given enough. I will reiterate that and say I've witnessed a number of your questions where you have not given the needed information.

So please, for all of our sanity, stop complaining. If this is not plain enough for you the next answer will be.

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Your answer is:
13A but now the next standard sized MCB has become acceptable. Which is 16A.

If the question is not specific, we end up with 6 pages of mainly noise. The prime question was:

How simple, specific and easy do you want it? I didn't get answers, not even one I wanted. Other people read this, with them having to read the unwanted noise as well.

A sub CU fed by a FCU is a common set-up. I had new house like this about 18 years ago. A whole estate was like that. I told the builders to run a full armoured cable back to an mcb in the CU. They said "no, it was legal and safe". I checked and it was within regs, etc. I didn't like it as the garage CU's main fuse was 16A with FCU's the fuse 13A. Clever eh. The 16A fuse was useless. If something was wrong in the garage i did not want to change a fuse in the dining room, wanting all garage protection contained within the garage.

I got around it by splitting the downstairs l'room/dining room and hall ring creating two radials on 20A mcbs. There was a spare slot in the CU. The 32A mcb was removed with two 20A mcb's inserted, one for each radial. The armoured cable was connected directly to a radial - the unswitched FSU was replace by a single socket. In the garage, the 16A fuse holder was removed. So, the garage CU had an incomer with a 16A mcb in the garage radial for the sockets, and one 3A mcb for the lights. The 20A mcb in the main CU protected the lot. Additional protection on each garage circuit. The garage radial cannot exceed 16A. 19A max inc lights. So if something was amiss in the garage the main CU 20A mcb would not trip only mcb's in the garage.

I had to split the ring, which was feasible. It may not be in some cases, so the spur cable off the ring has to stay.

SUNRAY said:

Absolutely not right, it is way outside of the regs and the special arrangements for a RFC. Dont get complacent just because it is so common.

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I never thought the 4mm cable was right.

SUNRAY said:

The RFC [originally called ringmain] and BS1362 & BS1363 were created for each other and the original maximum load was 13A but now the next standard sized MCB has become acceptable.

Click to expand...

So 16A protection for the spur. So a 2.5mm spur off a j box off a ring to garage/outbuilding, with a 13A mcb to a socket radial and a 3A mcb for a lighting radial (total 16A), is well within current regs.

Are you well?

hard-work said:

I didn't get answers, not even one I wanted.

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I think you got the answer(s) you needed to get.

hard-work said:

If something was wrong in the garage i did not want to change a fuse in the dining room, wanting all garage protection contained within the garage.

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If you spur from a ring in the house to the garage and then installed a small CU in the garage, any problems in the garage can still trip the RCD in the house CU. You'd lose some or all of the electrics in the house as well as the garage so that's very inconvenient and certainly doesn't provide 'garage protection self contained within the garage'.

That's 20 minutes of my time I will never get back after you lads have given him the attention he so desperately craves.

Note to self: Do NOT open any posts from Hardwork, because he certainly lives up to his name.