I've got 46 volts between black wire and earth

[coolhands]

well tell me in plain english. I went to change a switch which isn't unreasonable. I phoned an electrician too who in his own words 'talked himself out a job' by telling me to simply copy the original layout even though I explained the voltages didn't seem right. I've come on to ask advice as it didn't seem right even though the light works.

 

[DaftPunk]

The missing earth at the switch is a concern, but not as much as you replacing it while still live. We do not support suicide on this forum.

 

[coolhands]

ok I just tried the switch - the small box with the old fuse does indeed isolate the circuit Lesson learned.

I will now leave alone - but I am basically needing an electrician to sort out the earth is that right? Is it worth me checking the earth wire in ceiling rose?

 

[AndyPRK]

Don't try this if you don't feel safe.

How do you know you have a neutral at the switch?
What are you connecting to that is neutral?
Post a pic of the switch wiring.

Does the metal back box have an earth wire?

 

[coolhands]

there are 2 cables. One has red, black and earth. The other has red, blue, yellow and earth and links to the 2nd switch. Yes the earths at both switches are attached to metal back box.

I will post pic shortly its difficult as I am on a tablet not proper computer.

 

[AndyPRK]

Does the neon screw driver light when you touch the 2 external screw heads?

 

[coolhands]

here. Yes I first noticed the neon light up which is why I started checking with a voltmeter. I got the stated voltages when I checked between black and earth and red and earth on the incoming cable.

Untitled

• coolhands
• 17 Feb 2014
• 1

sorry hard to get pic on iphone there are some shadows in above pic

Untitled

• coolhands
• 17 Feb 2014
• 1

 

[AndyPRK]

Was your meter Set to ac or dc

There is no neutral at the switch.


I think I'm beginning to agree with your electrician but if the metal is live then its not right.

 

[coolhands]

yes I definitely had it on 500v ac.

 

[coolhands]

with switch connected and light on I get:
between yellow / ground 33v
between reds / ground 33v
between blue&black / ground 33v

with light off I get

between yellow / ground 89v
between red / ground 89v
between blue&black / ground 65v

perhaps there is no problem but can someone tell me how to check 100%the earth is not live as mow I'm worried.

edit sorry I wrote it wrong

red and yellow together, black and blue together, link cable red on its own.

 

[AndyPRK]

I think I would safely test your meter first. Maybe it needs a new battery

 

[ekmdgrf]

I did not isolate it since I couldn't

Just so that we can do another collective sharp intake of breath, perhaps you could share with us what steps you took to avoid electrocution?

 

[coolhands]

I'd rather have some help thanks

 

[ekmdgrf]

That sounds like a fair trade.