Borrowed Neutral

[DerbyBorn]

We have sold a house that our daughter had been living in. I had found that the wall lights in the lounge had a borrowed neutral from the ring main. I know this is wrong and realised that in order to be safe I needed to isolate all the circuits if I was to be doing any work on one of them (which I haven't) I have put a warning notice in the fuse box to warn of the situation. would you say that is the responsible thing to do - or might I have exposed myself to clams that I have sold the place with a known defect? I only became aware of the issue when I was decorating and saw the plasterwork covering a cable from wall light to socket.

[Graham.]

I understand that it is wrong, and I understand any RCDs will trip as soon as there is any load on the "other" circuit, but I need help understanding what is particularly dangerous about it.

[Tim Watts]

Someone disconnects neutrals from both circuits at the fusebox (or they fall off).

Person now isolates only the ring circuit but powers up the lighting circuit with its broken neutral.

Someone else turns a light on, which of course does not work but now makes the lighting circuit neutral "live" and from there the neutral on the ring which you are now fiddling with.

OK - it is a combination of more than one condition but the most famous cockups and resultant deaths often are.

And that's just one reason.

[Tim Watts]

No, I think you've done the right thing - you will remind yourself in any case.

[John Rumm]

So long as you did not sign the notice ;-)

[John Rumm]

The main danger is when someone wants to work on the circuit that the neutral has been borrowed "from". They could disconnect both its live and neutral at the CU and hence believe it is now safe. However they could still get a shock from the neutral since its not "floating" as they might have expected, but connected (via a load) to the live of another circuit.

[Martin Brown]

I found a much nastier one in my house with a borrowed *live* from the downstairs lighting circuit used to manually power the central heating pump in the loft from a light switch in the living room.

The switch was assumed not to do anything since no light came on.

[Fredxxx]

When I sold a house I said that the electrics should be updated, they were of the wired fuse type. Naturally the purchaser had the consumer unit changed.

I don't see any reason why you should not inform any purchaser of your concerns and shortcomings and recommend that the wiring is inspected by an NIC accredit electrician. Wouldn't you have provided this info in the information pack given to the purchasers?

An analogy could be you sell a car knowing the brakes were faulty. You would be in the clear if you informed a purchaser of the defect and recommended he had them looked at before he drove the car away; whereas if had kept quiet, and there was evidence you knew of the defect, and there was a serious accident you might find yourself liable!

[Fredxxx]

Not every house has an RCD. One with a borrowed neutral is likely not to have one, or at most a whole house RCD.

[nemo]

Sounds dead easy. If I was the purchaser I'd thank you for being so honest and, with the advice of appropriate experts, drop my offered price to cover the full cost of fixing it, including redecoration etc.

[Andrew Mawson]

And if I was the seller I'd say 'OK buy somewhere else !" - I did this when I sold my last place - buyer's solicitor was getting arsy about a tree in next doors garden with an overhanging branch - (I'd had a TPO put on it years earlier to stop them converting into a nursing home as they needed parking spaces :) ). I just told 'em, no problem go somewhere else! They didn't ! Amazing how a blank refusal stumps some people !

Andrew

[fred]

In article , Fredxxx writes

Not really a valid analogy IMV, one is inherently unsafe and the other is only unsafe under very specific circumstances.

Most of us will work on a circuit with just the live disconnected via an MCB leaving the neutral intact so having a borrowed neutral in this case makes no difference.

[DerbyBorn]

Fredxxx wrote in news:mhb94j$514$ [e-mail]:

It has wired fuses.

I doubt a standard inspection would show a fault - what do you think?

We declined a check as we said that in view of the age of the fuse box it would inevitably get a poor report. Money would be wasted by having the obvious stated, The buyer has seen the type of fusebox.

[tony sayer]

Not round here these days, you wouldn't give a toss about things like that, you need to get agreed and conveyanced before you get gazumped and a month later on need to find another Ten Grand..

Mad it is now!...

[bert]

The live for the light on our landing comes from the downstairs lighting circuit. Fortunately I found out before unscrewing the ceiling rose.

[Brian Gaff]

Well if the cable, ie the neutral ggot cut as it might is somone started working on where its burried, the live will go through the light if it was on and, well.

Who expects a live going one route and a neutral another? Weird. Any idea why it was done in such a manner? Brian

[Brian Gaff]

In such a case i think I'd take out the bulbs from the wall lights and put notes there explaining the defect, or if possible disconnect both the live and neutral of that circuit and make a note somewhere as to why its been disconnected. For what its worth, a lady was killed in her kitchen near here a few years ago by some idiot wiring under cupboard lights like this to get themselves out of trouble and make it a quick job. So please don't risk leaving it,

Brian

[philipuk]

You don't prove everything is dead before touching it?

I've seen enough crazy things in my time to know I'm not risking my neck on something when a basic check takes seconds. Check tester works, check conductors are dead, check tester still works, proceed.

Philip

[nemo]

That was (I'm told) a common practice in new builds in the middle of the last century, to reduce cost. It shows up when you upgrade from a fuse box to a modern consumer unit because putting the two lighting circuits on separate RCDs breakers won't work.

[nemo]

Such a test whilst good practice may show apparently dead conductors which can later become live when someone operates the light switch.