lights / bonding in bathroom

[sijaysee]

i have fitted mains halogens in a shower room. there is only a phase and neutral connection to join to. what do i do with the earths? also with regard to bonding , i was told on the course that i did recently "domestic electrical installers" that i didnt need any exra supplementary bonding from showers , heaters and lights to go to the hot and cold pipes because the earth acts as the bonding. so is that correct? page 30 of the onsite guide says "circuit protective conductors may be used as supplementary bonding conductors" this whole bonding business confuses me!! in the end all the earths and bonding go back to the fuse board and as long as continuity is maintained then thats all that matters

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Moderator

please read forum rule 20

 

[pdcelec]

Call a qualified electrician, to sort out the problems

 

[Lectrician]

I assume you are joining the T+E to the downlights flex with a JB?? Then just put the earth into a spare terminal.

If you are not doing it this way - YOU SHOULT BE, or atleast be using a crappy chock-box.


Re bonding, yes you can use the CPC as a bonding conductor, but all bonding muct be done in close proximity to the bathroom. So this rules out going back to the CU and back again!!!!

You need to link all earth terminals from each circuit together - that doesn't mean every light - just one, it doesnt mean shower and switch, it's either/or.

You must bond this to all extraneous metalwork/pipework - anything 'earthy'. This doesn't include copper fed via plastic pipes if the interchange is within the bathroom.

Bonding is difficult to explain online - everyones bathroom and situation is different!

 

[Adam_151]

You need to link all earth terminals from each circuit together - that doesn't mean every light - just one, it doesnt mean shower and switch, it's either/or.

I think it was someone on the IEE site that expressed the opposite of this, they should all be bonded, because the reg allowing use of the CPC as a bonding conductor apparently only applies to things like towel radiaters where you don't bond to the appliance, but to the fcu...

Thats the problem, the regs are too vague and people will interpret them in different ways

 

[sijaysee]

i junction boxed from the original light and then linked 5 downlights from there. are you saying that the earths at each fitting apart from the last one which is obviously a single wire should be joined with a connector block? then i need to take the bonding from the basin and run it to the shower earth connection and to a light choc block or the switch?

 

[sijaysee]

so what difference does it make if the bonding is in close proximity or not? like i said before, all those earths and bonding cables go back to the cu , so they are connected

 

[colport27]

Your question is number 10 of the nic`s top 10 of most asked questions to their technical department.

http://www.niceic.org.uk/approved/q...for the above mentioned opinions???????????

 

[sijaysee]

the bit i dont understand is , do i need to put a 4mm earth wire on the earth connection on the shower and then clamp it to the water pipe? because that looks horrible. or do i bury the earth in the wall and put a clamp somewhere accessible. maybe under the bath ?

 

[Lectrician]

Yup, I stick by what I have said - makes sense to me, and the nic chap that inspected my last job!

Imagine having to loop a 4mm earth to EVERYTHING.

Shaver point
6 downlights
extractor
mirror light
shower
shower switch
towel rail
and then the pipes....



Regarding close proximity - this is to keep the resistance of the bonding to a minimum, therefore ensuring an equal voltage is present at all terminations of the bonding conductor during a fault condition.

If the CU was backing onto the bathroom wall (rare, but have seen this in a block of granny flats), a 4mm earth from the CU to pipework would be ok.

Again, define close proximity!

 

[colport27]

You could take the earth out of the isolation switch for the shower.....and bond it to the pipe in the loft/airing cupboard.or from the shower isolator to the light and from the light to.........etc etc.

 

[sijaysee]

so i dont need to go from the actual shower. i could go from the isolater. ok makes sense. what about the downlights? they only have live and neutral connections. do i choc block the 1mm earth together with a 4mm bonding cable? and on every light?

 

[colport27]

Link all the earths through each fitting (good practice) but you only need to connect the 4mm to one of these connections.

 

[sijaysee]

u mean choc block the earths together? i dont need to earth the fitting do i? bearing in mind that theres nowhere to clamp an earth. and putting a 4mm earth in with the 1mm earth of the lighting cable seems odd and i dont recall ever seeing that before. couldnt i just take the bonding into the pull switch just like the shower ?

 

[colport27]

No you dont need to earth the fitting itself (should be double insulated fittings anyway, as your saying they didnt have an earth terminal).
Yes you can run the 4mm to the pull cord (im afraid I assumed there wasnt an earth at it from one of your earlier postings).
Never ASSUME as by doing so.u make an ASS of U and ME....lol

 

[sijaysee]

yea the earth goes from a joint box to the pull switch. i just wasnt sure what to do with the earths at each light fitting. i know a leccy that used to do a lot of work for me would just snip the earth off and disregard it.and he is a competant time severed leccy with 25 years experience