Hot earths.

[noviceone]

Hi all, I've just rewired all of the lights in my house (a 2 up,2 down terrace) using the "loop in system". It's the first electrical project I've done and everything is working fine apart from one thing. The 2 way switching for the upstairs landing light is working fine from upstairs and downstairs, BUT, the earths in the downstairs switch are hot. It's all plastic switch and both earths are connected to the brass terminal in the switch backbox. I've disconnected until I know whats wrong. Has anyone any ideas please?.

 

[RF Lighting]

Wild stab in the dark:

You have a dead short live to CPC some where on your lighting circuit, and the CPC is either badly connected to earth, or connected to a bad earth.

This maens there is a current flowng to earth, not enough to operate your OCPD but enough to warm the earths up.

Did you carry out an IR test before energising the circuit?

 

[JohnD]

Have you supplementary-bonded the lighting circuit to the bathroom pipes?

 

[noviceone]

No I didn't mate. I've got an electrician coming out to inspect it all in about a week but he's away at the moment. The downstairs circuit is only three lights so I've put them on a 13 amp plug just to see if they would work or not. They wont be wired to the consumer unit until the electrician comes round. Like I said,this is the first time I've done any electrics and I dont want to run before I can walk. ALSO,the bathroom and kitchen are on the extension to the house and are ok. The extension is 40 years newer than the house and all the electris are seperate and fine. The main part of house is being done seperately.

 

[Steve]

You need to inspect the supplementary bonding in the bathroom and upgrade if nessecary. Your earth resistance needs checking.

And i hope that plug you mentioned has a 5 amp fuse in it, or you're just making things worse.

 

[JohnD]

... I've got an electrician coming out to inspect it all in about a week but he's away at the moment....

I think I know the electrician you mean, he also does stuff for dancar.

 

[noviceone]

It does have a 5 amp fuse but it's unplugged for now just to be on the safe side. Think I'll have to wait for electrician but thanks for the input everyone.

 

[securespark]

Do you mean hot in the US sense, or as in raised temperature?

 

[noviceone]

The terminal was really hot,didn't give me a shock but it did burn my finger slightly. The upstairs circuit that I've done is fine. Going to look at the downstairs one this afternoon. I'd be chuffed if I can sort the problem before the electrician comes. I'll post an update later on.

 

[noviceone]

Had a look at the whole thing again. I was using a plug on the circuit,as I said,until the electrician comes to do the consumer unit. The connections on the extension lead I was using were bad (should have checked it before) and the earth had come undone in the plug . Now I'm using a different lead everything is how it should be. No hot earths etc. I guess that's it sorted. Does that make sense to proper electricians out there?.

 

[Lectrician]

Not really.

Loose earth in plug = high resistance earth.

High resistance earth = low current flow.

Low current flow = Little of no heat generation.




Umm - not sure on this problem - get your spark to dig for a soultion.




Could be a lost neutral combined with an earth fault, or a lost neutral on a PME install and a commoned earth to another supply. Could also be a live to earth fault with a high resistance earth.

 

[ricicle]

Are you on the muscle relaxant again Lec

 

[Lectrician]

Most deffinantly - did it affect my answer *hick*

 

[ricicle]

I'll read it again tomorrow, my Kronenbourgs kicking in now

 

[noviceone]

I'll leave it for the electrician to sort out I think. It does seem ok now but I dont know enough about electrics to do the fault diagnosis thing.