copied from electrics

[kmeeres]

I recently replaced my HW cylinder and discovered that the supply to the immersion heater which has been there for 20 years has a e-n short.

This is a dedicated feed and the board end was not earthed but has an MCB.

Running a new cable is not practical so immersion is dissed.
I would like to use this for a pump feed however.
Would it be safe to use a seperate earth feed.?
Would it be acceptable ?

A 4mm single core earth is available which goes back to the board.
Any special labelling requirments ?

Edit, to be clear this has already been done but having now discovered it can i use it ?

I already know the answer to this but.
The only way i know of the fault is that i went looking for it after noticing something else.
Tests at the outlet revealed nothing untoward.
Earth loop, phase etc.
The socket mentioned was installed by myself replacing the origional cord outlet.
I would not normally open up a CU - notifiable work.

Any comments from those who replace immersion heaters ?

 

[simond]

I would not use a cable which had clearly sustained damage along its length for any purpose carrying a 230v signal.

The very least you should do is carry out an insulation resistance check using a proper test unit running at 500v or above.

You know what you should be doing; running a new one.

 

[kmeeres]

I would not use a cable which had clearly sustained damage along its length for any purpose carrying a 230v signal.

The very least you should do is carry out an insulation resistance check using a proper test unit running at 500v or above.

You know what you should be doing; running a new one.

Dissed it off and meggered it , dead short.

What i am getting at is the way it was wired did not show up on the tests i would normally do before fitting an immersion.

Obvious once i opened up th CU that something was amiss n+ e both in the neutral bar. Earth had been supplied sepeately.
Only noticed it while putting in solar and saw a 4 mm earth into a junction box in the attic.

What i have surmised is. Origional board was wylex fused and either the problem was not spotted or a nail later caused the problem.
New board was later fitted with RCD where the problem was certainly spotted as n+e were stuffed in the same neutral hole.
Earth was supplied from somewhere which i suspect may be a pipe.
DIY suspected.