Spur from a spur

...provided that the new cabling isn't buried (or suitably protected). I must say that I'm a little surprised by the implication that a house re-wrired in 2003 doesn't have RCD protection of its sockets circuits, aren't you?

Nothing surprises me any more, but I would have expect it to be there.
But I have seen rewires performed by the uneducated and ignorant, that even post requirements fall somewhat short.
 
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All I can see is the single cable going into the socket. I do not know where the joint is. Lifting the floor is definitely not an option.
If you remove this cable from the terminals of this socket, what power-loss do you have? Don't perform any tasks without first proving dead with approved equipment, even if this cable is disconnected do not assume it has become isolated from the installation!

I do have access to the lighting ring. Would that be a better option?
Not for 13A demand you can't! You can if you wish, install 5A socket outlets for use of appliances with 5A plugs fitted, for a demand no greater than 5A.
 
All I can see is the single cable going into the socket. I do not know where the joint is. Lifting the floor is definitely not an option.
If you remove this cable from the terminals of this socket, what power-loss do you have? Don't perform any tasks without first proving dead with approved equipment, even if this cable is disconnected do not assume it has become isolated from the installation!
Is he not talking about the spur socket (which he can see a single cable going into)? - in which case what yiou suggest would obvioulsy not be helpful.

Kind Regards, John
 
I must say that I'm a little surprised by the implication that a house re-wrired in 2003 doesn't have RCD protection of its sockets circuits, aren't you?
Nothing surprises me any more, but I would have expect it to be there.
Same here - at least,if it were 'professionally' re-wired in 2003.

davejuk - do I take it that you are sure that this socket circuit is not already protected by an RCD in your consumer unit? If it were, then you would not need any additional RCD protection (RCD FCUs or sockets) for you extension.

Kind Regards, John
 
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There is definitely no RCD at the consumer unit. Last year I was quoted £240+VAT (I think) for a new RCD protected CU.

In the paperwork I got when I bought the house, I have an invoice dated 16th February 2003 for £1600 which included new lights, sockets, TV points, cooker, etc. in all rooms including a new consumer unit. Are you suggesting that this was not done to the regulations at the time if there is no RCD at the CU?
 
There is definitely no RCD at the consumer unit. Last year I was quoted £240+VAT (I think) for a new RCD protected CU.
Fair enough.
In the paperwork I got when I bought the house, I have an invoice dated 16th February 2003 for £1600 which included new lights, sockets, TV points, cooker, etc. in all rooms including a new consumer unit. Are you suggesting that this was not done to the regulations at the time if there is no RCD at the CU?
You'll have to look to others (I'm sure some will pipe in!) as regards details of earlier regulations. The current regulations, which introduced widespread requirements for RCD protection, didn't come into force until 2008, but CUs with RCDs were certainly being installed long before then.

Kind Regards, John
 
In the paperwork I got when I bought the house, I have an invoice dated 16th February 2003 for £1600 which included new lights, sockets, TV points, cooker, etc. in all rooms including a new consumer unit. Are you suggesting that this was not done to the regulations at the time if there is no RCD at the CU?
It may or may not have been an actual requirement at that time, depending on the type of supply you have (//www.diynot.com/wiki/electrics:earthing-arrangements), but for a new CU without any RCDs to be installed then was pretty shabby, not indicative of a conscientious professional.


2.5mm/30A cable
No such thing.
 
I understood that socket ring mains were installed in 2.5 mm2 cable - is that not correct?

BAS: At a glance, from those diagrams, my earthing arrangement appears to be TN-S (first image).

I'm obviously not an expert but if the work complied with the regulations at the time and in the absense of any other information, I don't think it is fair to describe the work as shabby. Every project has a budget. The work was done by the previous owner and they had a lot of other stuff done at the same time.
 
Budget does not trump safety.
2.5 T&E has an maximum current rating of 27A, which when derated factors such as ambient temperature, grouping of cables, method of containment routed within and the addition of thermal insulation where routed, can reduce that capacity greatly.
So 30A cable does not exist.
and yes 2.5mm T&E is a standard for a ring final circuit.
 
I'm obviously not an expert but if the work complied with the regulations at the time and in the absense of any other information, I don't think it is fair to describe the work as shabby.
I would personally not call it 'shabby', but certainly rather 'surprising'. What you have to understand is that, although there are a few amendments to the regulations published along the way, full new editions of the wiring regulations appear far more slowly than do changes in technology, products and practices - the edition prior to the 2008 regs was published in 1991, 17 years earlier. An awful lot changed in those 17 years and one would certainly have expected that by 2003, anyone having a re-wire and a new CU would have been advised to have, or at least be 'offered', an RCD (in those days, just one) in the CU, to add to safety - at an additional cost of maybe £30.

Kind Regards, John
 
I agree - I would have paid the little bit extra and got the RCD but you don't know the intentions of the previous owner. Maybe it was a buy to let investment that was already way over budget or maybe they just wanted to flip it. My point is that it doesn't indicate that the work was not of reasonable quality at the time.

I would always pay the extra for a mid-range tyre but plenty of people go for a budget tyre even though it means compromising on safety. That doesn't make the work of the garage that fits it shabby.

With regard to the 2.5mm/30A thing, you (ban-all-sheds and PrenticeBoyofDerry) seem to be being deliberately cryptic! I think you know what I mean - the socket has a single 2.5mm cable going to it and is protected by a 30A fuse at the consumer unit. I understand that factors other than thickness affect the performance of a cable but I was just trying to communicate the set up I am faced with.

Back on topic, the invoice says that the rewire in 2003 was completed in accordance with BS 7671: 2001 (formerly IEE Wiring Regulations 16th Edition).

Short of ripping the floor and walls apart, is there any way to test if it is a spur of a spur?
 
I agree - I would have paid the little bit extra and got the RCD but you don't know the intentions of the previous owner. Maybe it was a buy to let investment that was already way over budget or maybe they just wanted to flip it. My point is that it doesn't indicate that the work was not of reasonable quality at the time.

I would always pay the extra for a mid-range tyre but plenty of people go for a budget tyre even though it means compromising on safety. That doesn't make the work of the garage that fits it shabby.
Ah but they are both safe, having been designed and tested for their use.
The dearer one may be 'safer'.
You should not use budget tyres if they are underrated for your car's requirements and mid range tyres are unsafe on top range cars.

With regard to the 2.5mm/30A thing, you (ban-all-sheds and PrenticeBoyofDerry) seem to be being deliberately cryptic! I think you know what I mean - the socket has a single 2.5mm cable going to it and is protected by a 30A fuse at the consumer unit.
No - the single cable will be protected by the 13A fuse(s) in the plug(s).
There is an anomaly in allowing a double socket but you should not us two 13A appliances in one accessory but even then it is limited to 26A.

Short of ripping the floor and walls apart, is there any way to test if it is a spur of a spur?
Judging by their positions, you can test the other sockets to ensure they ARE on the ring.
Any socket with two cables which is NOT on the ring is likely to be a spur supplying another spur.
 
Short of ripping the floor and walls apart, is there any way to test if it is a spur of a spur?
You could dare I say it "test the circuit!" By performing a end to end tests on each conductor, this would either prove or disprove continuity of these, then a r1(live)+r2(CPC) continuity test. This will give a good benchmark of other sockets not solely part of the ring, any socket reading greater than 0.05 ohms of the r1+r2 could be put under consideration as a spur.
Probably the logical process would be to trace cable back to socket of origin, then disconnect the conductors of this cable, connect r1 and r2 of this cable together, then test r1+r2 at each socket/accessory, any socket/accessory offering a reading is part of that spur.
This is a dead test and I would in this instance for safety and to prevent damage to test equipment, isolate the whole system.
 
Maybe it was a buy to let investment that was already way over budget or maybe they just wanted to flip it.
Ah - you mean they put the price of a curry for 2 over the safety of their tenants or buyers.

Nice.
 

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