light swicth changing

Hi, I've just come to change our current light switches and this being my first time doing so (I've done plug sockets but not light switches), I've hit a bit of a problem and could do with some help. Taking the panels of the switches I see that each has just two blue wires one going into the com terminal and one into one of the lives. I was under the impression that blue was neutral. Shouldn't one of these be brown (live). The Brown wires and the earth wires seem to be looped through those little plastic boxes behind the switch with only the blue wires actually entering the terminals. Am I OK to just wire the blue wires into identical positions in the new switches. My concern is that I won't know if it is earthed, although I have to assume it is I suppose since it hasn't caused any problems as of yet. Any help or advice would be most welcome. Cheers
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Get it checked professionally. I'm sorry to say this, but the only time you should come across a blue cable with lighting switches is when it's part of a two way switch. And then there would be a yellow and red as well.
Blue as neutral and brown as 'live' only refer to flexible cables. The permanent cables inside the walls etc use black for neutral, red for line. If someone has used flex, it's a bodge.
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Obviously, this is changing in the future, but not quite yet. New colours will be blue/brown for fixed cable as well as flex.
I agree finding flex and dodgy chocolate block connections in the light switches screams bodge merchant.
Christian.
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Sounds like someone has bodged the job previously. I cannot think why there would be 2 Blue cables.
There should be two red (if done using correct cable to latest regs) or a red and black if using older cable, although the black is supposed to be sheathed red. It sounds like someone could have used some other cable, such as flex. Are you sure it is twin and earth?
Rob
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if it's rigid cable it's very likely 3 phase R/Y/B + earth
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hmmm. That sucks. By flex cable I assume you mean the kind I'd find in a plug. It does appear to be this kind, rather than the stiffer stuff I found behind the plug sockets. I would guess he (he being the idiot who previously owned our house) may have wired the switch (and presumably the wall light it controls) off the plug socket which is very close by (2 inch max). I'm sorely tempted to just wire them in as they are, given they haven't caused any problems in the 25 years or so the previous owners have lived there. Is it technically dangerous, as in exploding, or just not as it should be? Thanks for the advice by the way.
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That depends. If he's wired it into a nearby ring circuit with no fused connection unit, it is highly dangerous. The use of flex instead of cable for a lighting circuit probably isn't massively dangerous, but would certainly suggest that other more dangerous shortcuts may have been taken. I'm not happy about the use of unprotected chocolate block behind the box, for example.
Christian.
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Using the flex to carry a small current for a lamp is not the most dangerous thing in the world. If he has come off a ring main to do it, especially without a fused connection, then it is dangerous.
Technically, if you ever sold the house and the new owners had a problem with it, they could come after you. Equally, anyone who visited you and electrocuted themselves on the switch, cable etc would be able to sue you. It would be a hard case to prove but one does here of it, incresingly, unfortunately.
What I would be more worried about is that if he (the twit) was prepared to do what he has done, then what else is there lurking behind the plaster elsewhere in the house.
I can promise you an electrician would not touch it and probably insist on re-wiring half your house to their satisfaction.
Hope that helps. Rob
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Bodges can work for years without blowing up. Or not. It all depends on the bodge. If it's thin flex, it might be ok with small bulbs. Then you fit an LV set etc right up to the normal loading limit and the flex burns out rather than the fuse etc blowing.

You're welcome. House wiring properly is so cheap and simple there's really no reason to bodge. I'd check *everything* carefully.
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