I got electrocuted! A few questions....

[Lectrician]

It is more likely that the live has been squashed in the back box, or damaged by a securing screw. If had become disconnected, your light would not work.

Even if you have an earth cable present at the switch, this is not an indication that the earth is satisfactory. The other end of the earth cable must be connected too!

Any chance of taking some pics of the the wiring so we can judge the age and state of it?

 

[jdillon]

Sure, Ill take a pic tonight and post it up here.

Thanks for your help guys. Im keen to avoid ever experiencing something like that again!

It is more likely that the live has been squashed in the back box, or damaged by a securing screw. If had become disconnected, your light would not work.

Even if you have an earth cable present at the switch, this is not an indication that the earth is satisfactory. The other end of the earth cable must be connected too!

Any chance of taking some pics of the the wiring so we can judge the age and state of it?

 

[simon_m]

Say for example, if an unwitting soul happened to be changing a light fitting - unknowingly that the circuit was still live -and happened to touch the live and earth, could they have a fatal shock?

I stupidly did just this the other day. Switched the light switch off, switched live no problem, neutral no problem, earth no problem, hmm last two red wires to come out, bam, knocked me straight off the steps.

I am normally very cautios with these things but just was,nt thinkg that day

 

[jdillon]

I've started turning off all the electrics, not just the circuits I *think* Im working on ... mainly because the last owner of this house thought they were an expert and have circruits all over the place (if I turn off the upstairs sockets MCB, the fridge in the kitchen goes off!)

 

[plugwash]

It sounds like it would be a good idea to produce a plan of what exactly is on what circuits.

 

[jdillon]

Just a question about this.... the securing screw shouldnt touch the actual copper bit of the wire, just the plastic jacket, is that right?

Also, how would the live wire being squashed cause the faceplate to become live? (maybe when I post my pics it will be easier to understand)

Thanks!

It is more likely that the live has been squashed in the back box, or damaged by a securing screw. If had become disconnected, your light would not work.

 

[Lectrician]

It sounds like it would be a good idea to produce a plan of what exactly is on what circuits.

Or just be aware of the safe isolation procedure.

 

[jdillon]

Back to part of my original question, if I buy something like this:

http://www.screwfix.com/app/sfd/cat/pro.jsp?id=14469&cm_re=SEARCHPROMO-_-MULTIMETER-_-14469&ts=34220


and then touch each terminal to one of the switches that I tought when I get shocked, would this should a current flowing between the two and thus allow me to detect any other "unsafe" switches around the house?

 

[simon_m]

Just a question about this.... the securing screw shouldnt touch the actual copper bit of the wire, just the plastic jacket, is that right?

Also, how would the live wire being squashed cause the faceplate to become live? (maybe when I post my pics it will be easier to understand)

Thanks!

Are you talking about the securing screw for the faceplate?

 

[jdillon]

Just a question about this.... the securing screw shouldnt touch the actual copper bit of the wire, just the plastic jacket, is that right?

Also, how would the live wire being squashed cause the faceplate to become live? (maybe when I post my pics it will be easier to understand)

Thanks!

Are you talking about the securing screw for the faceplate?

Ah no, I was talking about the secrew that fastens the wire to hold it in place, not the faceplate screw

 

[Lectrician]

Hey you two - sort ya quotes out!

 

[rjb]

Those that are earthed should be ok right?

Just because a earth wire is present in your light switch doesn't mean it goes any where! As an earlier post said there must be continuity from the switch back to the earth terminal. Get a sparky to test.

A loose connection is usually the cause, just one loose tiny copper thread out of the termination could be enough for earth fault.

 

[electronicsuk]

Those that are earthed should be ok right?

As long as the earth wire present at the switch is actually earthed at the other end, then yes. With the correct equipment an electrician will be able to test the earth loop impedance and prove the earth is good.

Another question, for this to have happened the live wire must have come loose and have been touching the face plate, is that right?

It could have been touching the faceplate, backbox (if metal), or the shock could have been due to currents induced into a poorly earthed system. Your guess is as good as mine.

 

[davelx]

Just a question about this.... the securing screw shouldnt touch the actual copper bit of the wire, just the plastic jacket, is that right?

NO! That is absolutely wrong. The terminal screw should clamp the copper core securely between it and the body of the terminal. Anything else is a recipe for trouble as the contact is lekely ot be, or to become in a fairly short time, poor and loose,

 

[jdillon]

Hi,
yup, I think I understand. I was getting confused between the screw secruing the faceplate and the terminal one.