hazard light switch

[canter]

Last week I discovered a 2-way switch connected with 2 core and earth, using the earth as L1... I removed it. Now I've discovered another problem with another switch. I just wanted to replace a few face plates and discover the hazards I've been living with for 3 years! Anyway, this switch is 1-way. It was wall mounted and had a plastic face plate. I have put a metal backbox in the wall and connected a new stainless steel face plate. have put in the earth as it should be etc. When electrics are turned back on, the switch works fine, but when you touch the face plate you get a shock. Have checked all connections several times, nothing seems out of place. Have tried 2 different face plates - same thing. Any ideas? I've put a plastic face plate back on for now and it seems OK, but obviously want to know what's wrong. Thanks...

 

[securespark]

You obviously don't have an effective connection to earth.

Maybe that is why you had a plastic switch & box in the past. Re-instate these items until you can rectify the earth fault.

 

[bernardgreen]

If it is a "full shock" then the answer is obvious. The bare conductor that should be connected to the earth at the consumer unit has been connected to the live supply somewhere in the house.

If a tingle then the bare conductor is not connected to the earth or anywhere else.

Full shock = the shock from a metal object that is connected to 230v.
Can light a lamp bulb connected between the object and neutral

Tingle = the sensation from an un-earthed object that is capacitively connected to 230 v. Disappears if a lamp is connected between object and neutral, lamp does not light

 

[ebee]

bernard, whilst informative to say the least the terms full shock and tingle worry me that it might induce the enquirer to try it again in order to verify with lethal results.

Treat as lethal, do not touch, seek expert advice.

 

[RF Lighting]

For your own sake turn the power to this switch off, and leave it off until the cause of the problem has been ascertained and put right.

 

[bernardgreen]

I agree,

Wrong of me to be so flippant.

 

[securespark]

I have seen this three times in my new job, and twice it was down to this:

The two-way switches were connected to each other cpc wise, but not to an earth conductor elsewhere.

 

[RF Lighting]

What is your new job?

 

[securespark]

Same as the old one, but now I'm PAYE, not S/E.

I do house-bashing with a lot of fault-finding. Very little installation work. Mainly like for like changes, fault-finding & repairs, including shed-loads of RCD-related problems. See new thread...

 

[canter]

Thanks for this. Don't worry, I'm not going to test out the full shock/tingle test! Whatever it was it was not fun. There are two light circuits in the house - upstairs and downstairs on separate fuses. This switch is on the downstairs fuse - but I did notice that when the live wire was in L1, the bulb came on dimly when the upstairs fuse was switched back on and then more fully when the correct fuse was switched back on. The switch was also switching the wrong way so I put the live wire in L2 instead and the switch worked the right way and the thing with the bulb coming on dimly in response to the upstairs fuse went. Don't know if this sheds any light on it at all - would be interested to know, but like I said, don't worry, I won't be testing any shock theories and will get someone in to take a look!