Shock from lightswitch/radiator

[D.M. Procida]

I was assuming that it was indeed a genuine earth-gone-live fault (and would Pete have received such a shock otherwise?).

Daniele

[meow2222]

probable? Surely he'll know for sure.

again there shouldnt be doubt after a couple of simple tests.

Part P doesnt prevent that

You have a dangerous circuit. The first job is obviously to fix the lighting circuit. The amount of extra safety you'll get from updating the cu is trivial. Not only would it require the spending on the job, but may also then require extra work downstream (more =A3) plus inspection costs (=A3 again). In terms of safety benefit per pound spent its not constructive. The risk of electrocution in the home is miniscule compared to other normal domestic risks.

Unless I know the contractor well enough to trust them to decide the bill, and that isnt usually so, I request a fixed quote for the job, and if they wont provide one, go elsewhere. Otherwise you're effectively agreeing to sign a blank cheque, and hardly surprisingly, the amount will always be more than you ever wanted it to be. There's nothing impossible about the spark giving you a fixed price, its just basic business skills. Of course they don't like to, they'd rather have the day's work in which to soften you up for a higher price and get you over a barrel.

A responsible spark would have removed the fuse in the CU. Is it fitted with metal or plastic screws? If they're metal, its still potentially lethal, and I'd say enough is enough and get someone else in.

You're almost unique in caring. Its not unsual for councils to have received zero DIY part p compliance applications.

NT

[Dave Liquorice]

Capacitive coupling is well capable of giving you quite a tingle but nothing like a belt from the mains. Has Pete ever had a direct contact shock from the mains? If he hasn't he might think "quite a tingle" is the mains.

IIRC this was also a hand to hand shock. If it was direct mains, I'd expect him to have reported numbness/tingling down both arms for several hours afterwards and achey elbow and shoulder joints. Those are certainly the after effects I've had after picking up the mains. Fortunately all belts so far have been confined to across a small distance say a finger or side of hand. The worst was hand to elbow.

[D.M. Procida]

I've had a couple, but one of the nastiest wasn't actually mains, but

450V. I was working in a factory that made meters (moving coil meters, in my case), and got it from hand to hand, right across my chest.

Apart from the shock itself, which I felt go right through my heart, my whole body felt as though it had been wrung out like a cloth for hours afterwards.

Daniele

[The Real Doctor]

Why? We went to 230V years ago. Or are you expecting a -10V earth?

Ian

[The Natural Philosopher]

Ah but its a Nu Laber 230v, like the crime rate. Its *specified* lower because we were always 240v, so its 230v +5%..;-)

[Dave Plowman (News)]

No we didn't. The actual voltage hasn't changed. Only the spec.

[Martin Bonner]

No we didn't. The standard is now 230V +10% / -6% - but the CEGB still tends to push out 240V +/- 6% (which happens to be towards the top end of that range).

[<me9]

Mine's rarely above 234, currently 225 but it never has been any higher. We're far from the sub station. when we used incandescents they rarely failed.

At the previous house we were very close to the SS. We had a good stock of bulbs when we moved in, but in a year they had all blown. IIRC we were nearer

250v there.

[petek]

Just to bring this post to a conclusion I thought I would update you all on the outcome.

The fault was eventually traced to a nail fixing the skirting on the upstairs landing which had been hammered through the 3core+earth cable used as strappers for the 2-way light on the stairs. The nail was touching the bare earth wire and had penetrated the insulation on the blue wire. This must have been done when the house was built in 1979 as no other work has ever been done in this area (we've lived here since the house was new). It was a devil of a job finding the fault. We had to isolate every light on the circuit by disconnecting the live, neutral and earth wires at each rose and switch, and testing each one individually. Sod's law applied as the staircase light was the last but one on the circuit and hence the last but one to be tested. I then had to cut a section of chipboard floor out for access, and cut a chase in the landing wall to get the defective cable out, and install a new length.

The earth wire in first section of the upstairs lighting circuit (i.e. between the CU and the first light) had been cut back at both ends and not connected either at the CU or at the ceiling rose of the light. So even though all the other earth wires in the circuit were connected, the earth was effectively non-existant. I strongly suspect this was done deliberately when the house was first built in order to conceal the short circuit as the leccy at the time probably couldn't be bothered tracing the fault. We have upgraded the CU from old style wired fuses to a RCD/MCB type and ensured that all earths are properly connected.

I have taken a chance on the Part P thing, and used the leccy I originally got in (who was a JIB Approved Electrician if you remember from my previous posts). He seemed to me very competent, and welcomed me acting as his "apprentice/assistant". Total cost was =A3275 (=A3210 for the CU and =A365 for tracing and fixing the faulty cable) which included materials and 11 - 12 hours labour over 2 days (most of the labour time was tracing the fault).

Thanks again for all your constructive comments. It really does help being part of this group and I enjoy participating immensely.

Pete

[<me9]

[snip]

[snip]

Same age as this house. Built in the days of very fast construction with crude bonus schemes which were on amount constructed rather than constructed properly. I had a broken earth to my upstairs lights due to the cable being crushed when the upstairs floorboards were installed This also fed a class I heater in the bathroom, which as a result wasn't earthed, and hadn't been found on the (probably non existent) inspection.

I had a friend who at the time was doing flagging (elsewhere) for the same builder. Bonus per flag laid. He did all the whole flags on an estate and then packed in. Got his bonuses, and the builder had to get in contractors to complete all the fiddly bits.

[John Rumm]

Thanks for the update Pete. It's nice to know the eventual outcome of these things.