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Supplementary Earth Bonding!
Surrey Dave - 9/5/07 at 08:44 AM

What is the method of carrying out earth bonding of the bathroom , if you do not have an earth in the light fitting to to connect to????


twybrow - 9/5/07 at 08:56 AM

Re-wire! The earth wire now needs to be a seperate earht wire runnign direct to your breaker box. The rules are very strict and demanding. In theory, you cant even begin to do this work yourself! If you do, then you should have it inspected.

When I did ours, I actually used the earth wire running from the electric shower (50A cable!) as we were switching to a much lower rated power shower.


Lawnmower - 9/5/07 at 09:20 AM

As I understand it, the bathroom has the strictest wiring regulations in the hjouse (apart from the actual connection to tne household supply/meter).

I am currently doing my kitchen and hope to do the wiring over the next month. I will be getting a pro in to do the final connections, as the existing circuit also runs off upstairs!, and to get the paperwork so that when I sell its all their. (I also moved in after the regs changed, so I cant blag it either)


Lawnmower - 9/5/07 at 09:21 AM

earth bonding - surley to the cold water pipe?


twybrow - 9/5/07 at 09:30 AM

From water pipes, to a major earth wire. You could always claim you haven't changed any wiring when you move out (who could prove otherwise!?)... Alternatively, I think a sparky will charge you around £60 to inspect.


Lawnmower - 9/5/07 at 09:40 AM

quote:
Originally posted by twybrow
... You could always claim you haven't changed any wiring when you move out (who could prove otherwise!?)...


except that the colour coding of some wires changed (may not be that relevant). Also it may invalidate your buildings insurance, so if you claim, say for a break in, they may refuse to pay out cos you changed somthing totally unrelated.
Insurance companys = the devil


Surrey Dave - 9/5/07 at 11:43 AM

I could run an earth back to the main block under the consumer unit , but I thought that was not good for earthing the bathroom.

or I could connect an earth in ring supplying the bathroom heater.

I dont like the idea of connecting anything in the bathroom to a potentially live socket/connection.


I am going to run a 10mm earth from the main water pipe ( within 600mm of stop cock), back to the main earth block and earth the gas pipe there too.



[Edited on 9/5/07 by Surrey Dave]


bartonp - 9/5/07 at 11:50 AM

NO NO NO NO NO!!!!!

Equipotential bonding - getting all the exposed metal parts bonded together NOT TO EARTH.


JonBowden - 9/5/07 at 11:59 AM

That's how I read the regs too. IE, no electrical items should be connected to earth but all exposed plumbing and light fittings should be bonded together.


Surrey Dave - 9/5/07 at 12:08 PM

So back to my original question , it's not important that my light fitting has no earth.

I just connect all the metal parts in the bathroom and connect them to the earth connector on the light fitting because it is a) metal and b) because it is in the bathroom.


nitram38 - 9/5/07 at 12:22 PM

From a qualified spark

Firstly, if you can test the installation, you do not need equipotential bonds if you can prove that the earthing works without them.
But I would recommend always doing them incase things change in the future, such as plumbing modifications.
You only need to bond between exposed metal surfaces etc.
If you bath is fibreglass you do not need to bond the frame underneath, unless it is exposed.
I would use good quality earth bonding clips with 2.5mm single earth cable under your bath/sink etc between all metal pipes. For exposed areas, use 4mm earth. Also if you have an electric heated towel rail/radiator, I would run the earth back to the earth in the wall outlet (this should be a blank plate and not an isolator/switch).
Any radiators also need to be bonded.
Your lighting may well have an earth, but the fitting must be an ip rated item or low voltage/ ip rated.
If the person in the bath or standing at the sink can reach any lights metal parts (there should be none) then a bond must be connected here too.
Don't worry too much as this is an easy job to do.

Don't forget to bond your electric shower too!

[Edited on 9/5/2007 by nitram38]


bartonp - 9/5/07 at 03:53 PM

quote:
Originally posted by Surrey Dave
So back to my original question , it's not important that my light fitting has no earth.

I just connect all the metal parts in the bathroom and connect them to the earth connector on the light fitting because it is a) metal and b) because it is in the bathroom.


Yup (if it's metal and exposed). Check regs to see if it's 4mm or 6mm or 10mm cable (I forget with doing ind stuff)


ady8077 - 9/5/07 at 04:34 PM

Hi, you'r supposed to join all exposed metal work and the earths of all electrical equipment in a bathroom together

Or you could wait until next year, supp bonding is being dropped from the new regs, instead every electrical item in a bathroom has to be on an RCD

Adrian Rescued attachment suppbond.jpg
Rescued attachment suppbond.jpg