Replacing Light Switch - Safety Advice Requested

dave8427 · Dec 19, 2013

Hi. I need to replace a light switch and have researched how to do it and feel confident I can achieve it. The only thing that worries me is the potential for an electric shock. I'm on a budget and I'd rather not shell out on a mains tester if I don't need to. Also, I've heard they can give you a false sense of security. So what I want to know is, would it be safe to work on the light switch if I turn off ALL the electricity at the box, lights and everything? I know the fridge will start defrosting, but I think I can get the job done in about 20 mins or less, so that wouldn't be a problem.

Thanks for any input.

Sintra · Dec 19, 2013

You still need to prove that the circuit is in fact dead with an approved voltage tester. Advice other than this would be putting you in danger.

ifindoubtdont · Dec 19, 2013

Do not use the dummies way of testing for live. ( Lick fingers, touch wire, count number of walls you bounce off. If number greater than zero, it was live. ). Invest in a local electrician, we can be tamed quiet easily. Tea, biscuits and a bit of folding and you will have a friend for life. Watch carefully how they do it so you will know for next time but if you get stuck you can always phone a friend. Said job would probably cost about the same as a tester if they happened to be passing. Post your location, someone on here may be close by.

dave8427 · Dec 20, 2013

Thanks for the responses. I'm going to err on the side of caution and get myself a mains tester/screwdriver thingy today. I've also found a digital multimeter in a drawer, but I don't want to use that yet, seems a bit complicated and involves contacting the probes on a potentially live circuit, which I'm not confident enough to do. What I'll do is, satisfy myself that the power is off with the mains tester, then ask for further advice on how to check with the multimeter. I won't attempt the job before being 100% certain that the power is off. I'll update you before doing anything if that's OK. Better safe than sorry.

telectrix · Dec 20, 2013

don't waste your money on a neon screwdriver. bloody useless and potentially dangerous. for a DIYer, a non contact voltstick is preferable. test at switch with power on, it will light up. turn power off, it should then not light. obviously, this is not the approved method of proving dead, but if you were to buy the correct tester as approved , it would cost you as much as an electrician would charge to do the job.

Sintra · Dec 20, 2013

dave8427 said:
Thanks for the responses. I'm going to err on the side of caution and get myself a mains tester/screwdriver thingy today.

As Tel has stated do not use a neon screwdriver. It uses your body as part of the circuit and can potentially kill you if it's faulty.

dave8427 · Dec 21, 2013

Darn it, I bought a neon screwdriver before I saw the advice not to. Not a problem as I can change it for a non-contact tester later on today. Would this one do the job?

Philex 83010HS Electronic AC Voltage Detector Pen | Screwfix.com

It says it detects CAT III 90-1000V AC Voltage. Will that be suitable for my light switch do you think?

onions1066 · Dec 21, 2013

Seriously mate your asking electricians to tell you how to do our work, I think the responses you've had so far are as helpful as your going to get. If you went to a car garage and asked them how to change your alternator do you think they would tell you? For the time you've spent sourcing a tester and the time you've wasted and the petrol you've used going to get it you could of got an electrician to do it. Even with a non contact tester you will need a known source to prove it on once you've turned the power off.