Dodgy House Wiring...(Refugee)

[pwdrive]

Hi Ref, my little quiz/puzzle that you were participating in got pulled on the other forum for whatever reason, here's the answer.

The feed for the mains sockets came from a small distribution board via one of its fused outlets, there was no cable return to that point (was expecting conventional ring)

It turned out that there was a return cable but not to the outlet fuse on that distribution board but to another fuse on another small distribution board.......dangerous for the unwary...nearly caught me out when working on it 'cos I couldn't find my neon screwdriver...

I had assumed that the single cable from the first distribution board was just feeding the sockets as spurs so I switched the main switch off on that distribution board to isolate...not so...I happened to plug in a lamp to test that the sockets were dead and the lamp it lit up!!!

All ripped out and done properly.

Lawrence.

[ppppenguin]

Radial circuits feeding sockets are a standard arrangement and have been since at least the 14th ed regs. Before rings they were the only arrangement. Either 20A breaker with 2.5mm cable or 32A breaker with 4mm cable. It''s possible that rings will be abolished in the 18th ed regs and it will be radials only.

Having a pseudo ring between 2 dist boards is obviously nasty. I once encountered something similar where 3 rings had been scrambled at the fusebox and you had to trip 3 MCBs to deaden them.

While many of us use neon screwdrivers and voltsticks, they don't guarantee safety. You need a proper test lamp (Drummond lamp) for that. I admit that I'm guilty of this crime quite often, but usually on installations with which I'm familiar. I also make sure that the neon screwdriver is in good condition and that both it and the voltstick are proven working by touching them to a known live cable.

Golden rule: Never assume a circuit is dead just because you've switched off, tripped the breaker, pulled the fuse etc. Prove it before touching. Similar rule applies to radio and TV mending too. Pull the plug before touching something potentially hazardous - a visible break in the circuit is good proof that it's not live. Apart from stored charge

[pwdrive]

That wasn't the end of the horrors, there was an old caravan/mobile home in the garden, the type you would have seen for rent in seaside holiday parks back in the day, it leaked like a sieve so decided to build a new one, the old one had electric feed, a bit bigger than 2.5 T&E but not that much bigger laid across the grass from the house to a multifarious choc block all taped up in the caravan, coming out of that was a feed to some outlet sockets and a feed to a free standing electric cooker (4 rings, grill, oven)
Not only that, it fed an immersion heater as well....mind boggles.

Lawrence.

[boater sam]

We used to work on some odd properties, flats and bedsits converted back into houses or flats.
Finding 2 or more radial circuits "converted " into rings were common. Often they were a tangle of 4 or 5 circuits joined together hopefully as rings. Multiple fused feeds happened quite often, frequently on different floors even.
As we were often in partially occupied buildings were all power could not be turned off, the risk of electrocution was to be considered at all times.
We also had commercial properties converted into housing, with 3 phase supplies. 
The golden rule was to test isolation twice preferably using 2 methods, then before touching anything, the old screwdriver across the connections finally guaranteed confidence.

A memorable job was an old building with all the meters and dis boxes in an external passage.
An art cut and paste business had taken over lots of different offices and store rooms. There were 13A sockets everywhere on all sorts of sub dis boards, radials, spurs, rings. Lights were mix of dedicated circuits and switched spurs off the power circuits.
We went through the lot identifying fuses and insulation testing circuits. The business was pushing to get up and running fast so they started before we had finished.
There was a complaint one morning that at certain times of the day some of the power sockets went off, but came back on again usually next morning.
The answer? some of the socket had been removed storage heater outlets that had had 13A sockets fitted, but the remote room thermostats were still in circuit!

[Refugee]

My place is a bit of a mess and it still has a Bakelite fuse board.
The ring main goes round upstairs and all downstairs sockets are spurs from the ring main.
It needs a lot of work.

[Cleggy]

I've been in my (1960's) house over 20 years now and always thought everything was fine. All was surely safeguarded by the RCD which sits next to the Wylex consumer unit? Wrong!!! A couple of months ago circumstances arose which led me to discover that the "RCD" is in fact a Crabtree voltage operated earth leakage circuit breaker  https://www.flameport.com/electric_museu...elcb_2.cs4

As some of you will know, these were a very common fitting pre RCD's and there are lots still around apparently. Sadly, they are not actually very useful and unlikley to save your life like an RCD should do.

So, I'm cancelling Christmas so we can have a new consumer unit installed .

C

[Refugee]

I blew one of those ELCBs up when I was a teenager when I dropped a steel washer that landed between live and earth by mistake.

[ed731pdh]

Old house in London, an 1870s terrace that had been retrofitted with lighting sometime in the 20s, had that rubber coated cable that had a nasty habit of powdering away.  Always remembered as a kid a ground floor light socket needing replacing and the 1st floor boards up to gain access. My old man ended up across the room and halfway down the hall before be found a bit that didn't crumble.

Always remembered needing an adaptor, per room, to run the hoover due to the various different standards.

No ELCB, no nothing, just a ceramic fuse box with a bit of asbesdos behind the fuse wire, and a Lucy Oxford company main with live and neutral fuses fitted.

Was a breath of fresh air when the house was rewired with ring mains, and I'd be dissapointed if as mentioned we go backwards to spur wiring and giant US style distribution boards which need to be shoehorned into god knows where.

[ppppenguin]

Was a breath of fresh air when the house was rewired with ring mains, and I'd be dissapointed if as mentioned we go backwards to spur wiring and giant US style distribution boards which need to be shoehorned into god knows where.

Radial circuits with 32A MCBs and 4mm cable need no more fuses/breakers than ring circuits. Radials with 20A breakers and 2.5mm cable might need a few more than with rings. Probably no more than 2 more in an average house where you might have 2 rings, one for each floor but 4 20A radials.

[ed731pdh]

I still have nightmares when I see American style distro boards...