Electrics

Dec 06, 2006 75 Replies

I'm sorry but I must disagree. It is entirely possible that a numbskull shaved some pennies off his budget by doing a major rewire himself. I suggest that's possibly more likely than someone who knew what he was about doing this "in a rush" and getting it wrong.

The OP says he has moved into a new house. I assume that's a new house to him, but it's rather an old house which he's taken on from someone else who lived there before. If it was a new house then the builders would be very interested to know why their electrician is wiring properties up with black and red, because today's colours are orange and purple (okay, I'm kidding - it's brown and blue).

With respect to whether this reversal is safe, the hell it is. If these wires are indeed reversed then the fuse is on the negative, and the live on the faulty equipment is still surging unabated.

The only way the OP can be sure of this situation is to hire a trained electrician in. Depending on this newsgroup to give advice about such a serious matter is at best foolish.

Andrew

yebbutnobutyeahbutnobut if you put one wire into L1 and one wire into L2 then the light will never come on.

Owain

Of course, if the fuse is on the negative, that implies that he has a DC supply which would be unfortunate in many ways, such as most fuses and appliances only being rated for AC. (Sorry, Couldn't resist. Friday night at pub...) Martin.

........and anyway there is this fing wot you don't know anyfing about, I earned £30 the other day because someone had done this, but she had been behind the bike shed wiv andy hall, so shes a slag, so don't believe her anyway.

Except that with a two way switch wired for one way you need to have the common as one of the terminals otherwise it won't work. Not dangerous, though.

I don't advise fiddling with electrics unless you have at least a basic idea how things work.

Not so. Reverse line and neutral at a socket and the appliance fuse in the plug is now in the neutral. And it doesn't take too much imagination to have a fault which blows that fuse and leaves the casing of the appliance live...

Indeed, if the fuse in the plug is in the *neutral*,. I can easily imagine a fault where the cpc/earth in a 0.5mm**2 flex blows before a 30-A rewireable fuse in the CU if the polarity is correct there, or a

100-A supplier's fuse if not. But I was being nasty about the mention of *negative*...

:) Point taken.

I did of course mean neutral :)

Andrew

One can imagine anything in the world, it means litle. What counts is whats actually happening in the real world. Such reversals are a small safety issue in reality, not the big alarms some people seem to think. You only need look at the known death rates. If you want to do something about safety you need to be thinking more about your bed, beds cause far more injuries than electrical wiring. Ditto cookers, stairs, roads, children, and many other things all orders of magnitude more risky.

NT

It will if you hit it hard enough :)

NT

They're only a small safety issue since they're rare. Only a total pillock gets line and neutral reversed in permanent wiring.

I work in TV and much of the work involves location shooting. If possible we'll use local power rather than a generator as most places can cope ok with our low lighting load. So at recce time, each and every premises is checked for earth and polarity, etc, including the actual sockets likely to be used. Earth faults are common. Line neutral reverse not.

Ladders being a prime example. One of the most dangerous things you can use, but freely available.

Oi. I have my standards I'll have you know.. Inside the bike shed....

Bike shed? Bovvered? Bike shed? Bovvered? Are you disrespecting me? Bovvered? I A'INT BOVVERED!

Any the most dangerous thing of all - anyone know?

NT

I have read petrol chainsaw.

Consider this. Half the population dies from heart disease & cancer, and half of that is estimated to be avoidable & caused by people's own actions. A quarter of the population kills themselves in this way, by actions committed with denial. The most dangerous thing people own is themselves.

There are others in the top 10 killers that arent talked about too, while electrical safety (kills less than 20/yr) is a familiar topic. Britain lives in denial about the real safety issues.

NT

So 'avoid' it and live forever?

Agreed, if someone invented the car today it would not be allowed on pure safety grounds. Around 8 people/day are killed in UK road "accidents" (3,221 in 2004, 3,201 in 2005) and about 750/day are injured.

I'm sure it's a very nice bike shed.

Temperature and humidity controlled to prevent rusting and deterioration of the brake rubbers.

A little hydraulic turntable on the floor so you can cycle in and it turns around automatically for you to cycle out.

Walk-through shower and blow-dryer.

Solar-powered charger for the lights.

Anatomically-correct frame in a centrifugal dessicator for getting the sweat out of the lycra shorts without shrinkage.

Owain

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