Bonding of shower enclosure

[bluetobits]

Hi folks, just got back from a mates house for a few beers and was discussing his new bathroom. He has installed a new shower off his gas boiler (real fancy thing with thermostatic electronic mixer in loft) with a nice aluminium enclosure in his bathroom. As the enclosure is aluminium framed, does it need cross bonding with other extraneous parts? I initially said it should be but then second guessed myself. No RCD on any circuits.

 

[NozSpark]

Absolutley no requirement to bond things that aren't extraneous.

Do you bond metal door handles and hinges also??

 

[bluetobits]

Absolutely not, but why is a metal shower enclosure not extraneous?

 

[NozSpark]

because it isn't connected to earth in any way

 

[bluetobits]

I see, unlike radiators and pipes. Thanks for that.

 

[SPECIAL LOCATION]

Absolutely not, but why is a metal shower enclosure not extraneous?

Hello blue,

If you ever have any doubts about whats what..

always worth a look in the "Definitions" section of the regs...

Part 2, page 24 big red book...

11th item down you will find Extraneous conductive part.

Or you can do a simple test...

If you put a continuity meter between your metal enclosure and the Main incoming earth terminal

if it is open circuit (or at least >20Kohms) its not extraneous.

i.e. unlikely to introduce an earth potential.

Guinness

 

[paul b b]

i guess this would mean that most water pipes in the future will not need bonding.

i was on a job the other day where the water was plastic for the first 4 inches, even the stopcock was plastic.

 

[ianmacd]

Remember that an exteranious-conductive-part is any part liable to introduce a potential and not just Earth potential.

 

[springcrocus]

i guess this would mean that most water pipes in the future will not need bonding.i was on a job the other day where the water was plastic for the first 4 inches, even the stopcock was plastic.

I would still bond the water pipes at the first available bit of copper.

Consider the possibility of, say, an immersion element with a pinhole in it. This could cause the tank and associated pipework to rise to a high potential, especially in hard-water areas. The dissolved salts in the water make a fairly good conductor.

 

[Andy™]

I would still bond the water pipes at the first available bit of copper.Consider the possibility of, say, an immersion element with a pinhole in it. This could cause the tank and associated pipework to rise to a high potential, especially in hard-water areas. The dissolved salts in the water make a fairly good conductor.

which is why the immersion heater has an earth connection to it...

also, if the immersion heater failed, then the pipework would be live because of a fault with the installation. not live because of external influences

if a propety has a plastic incomer, then chances are, the pipe is not extraneous, and may not need bonded. i normally still bond though, unless its impractical (even if the incoming is plastic, if any of the copper touches soil under the floor, it could be made extraneous because of that)

 

[batty]

It is a differcult one with more and more plastic being used in installations but parts being copper its a job to know what to do. The copper will have a resistance because the cpc of the immersion cable will give it a low resistance but its not going to go down to earth because the rest of the installation is plastic.

 

[tom1]

[quote name='Andy

 

[batty]

seen a few were water pipes are run in the concrete from one room to another

They are generally sleeved nowadays though.

 

[Andy™]

seen a few were water pipes are run in the concrete from one room to another

correct, but i was aiming it more at pipes taken under downstairs floor - may no be supported, or istalled on soil from day 1

 

[bluetobits]

See i've opened a right can of worms here, Hope that doesn't need bonding too.

 

[Andy™]

i would have thought the worms would be well earthed...

 

[bluetobits]

Damn, wish i'd thought of that! :Applaud

 

[SLIPSHOD & SLAPDASH]

Now this has got me thinking, I have a large job that has a lot of on-going work. It has had all its ground floor heating pipes replaced due to corrosion as originally being laid in concrete. Metal troughs have now been laid throughout with new copper pipework within. I suppose all this trough work could introduce a potential. Also as i can't be bothered to look it up, is it ok to have copper touching galvanised steel ?

 

[SLIPSHOD & SLAPDASH]

http://wiki.answers.com/Q/Can_copper_touch_galvanized_metal

 

[Apache]

is it ok to have copper touching galvanised steel ?

It's why old Landrovers fall to bits - the metals react like in your link, nowt to do with rust as people always think.