Bath Bonding

It doesn't need to be bonded. A totally isolated metal object is fine, earth bonding it actually increases your risk of electric shock. Read this for background detail: http://www.iee.org/Publish/WireRegs/EarthingPlasticPipes.pdf It's written by Paul Cook. He's secretary to the IEE/BSI Technical Committee who are responsible for BS 7671. So you could say he 'writes the regulations'.

 

Are the pipes to the tap bonded?
My thoughs are that the bath should be bonded, tap water is a conductor and when your running the bath there will be an electrical path between the taps and the bath.
In a fault condition the bath metal work could be at a different potential to the taps.
and so if you touch the bath and the taps at the same time, ouch.
The aim of bonding is to ensure all metal work is at the same potential and thus remove the risk of shock.
I'd play safe and bond it.
It'll only cost you a few quid if you do it your self.

 

lastword is correct. It is a common misconception that water in the pipe conducts fault current. It doesnt.

 

Depends upon how ionised the water is; how much minerals are present - electrolysis!

Usually, I bond the bloody lot to make sure I haven't missed anything. Unless its SELV/PELV or something like that.

 

This topic does seem rather too complex, even though the subject matter and reasoning is really simple to understand!

The situation I'm grappling with is a new steel bath where the taps are connected via long flexi connectors, these connectors are bound in nylon, not metal sheathing. The waste pipe is plastic, so there's no direct electrical connection to the bath.

The learned opinions I've received about this situation advise that the bath shouldn't be bonded, which is fair enough. However there is an electric water shower pump hung on the wall about 6in above the bath, fed by copper pipes which are bonded (correctly) which run alongside and around the bath - these pipes are insulated from the bath via plastic conduit. In the conduit also runs the power cable for the pump.

My take on this has been that the bath ought to be bonded because of the possibility (remote or otherwise) that there might be a breach of the electrical cable or other pipes. But I can understand the alternative suggestion as well.

Confused residing in the UK!

Gotcher

 

water in pipes counts as an insulator, so long as the insulated section is long enough. 1m of plastic pipe is probably long enough. 1 cm is not, would count as already poorly earthed so bath should be bonded. 10 cm might be an insulator, depending on the quality of the water. clear as mud. But see other posts with links to discussions about this

 

BS7671 (IEE Wiring Regs 16th Ed) is clear about this point. All exposed conductive parts and extraneous conductive parts (i.e. all metal parts) should be connected by supplementary bonding (see 601-04-02). This is confirmed in Guidance Note 5 Protection Against Electric Shockand in the On-Site Guide which also state that connection back to the main earth terminal is not required. If you want to comply with BS7671 then do what it says and ignore the mostly irrelevant answers that you've been given by others.

 

Engineer, for the avoidance of doubt, where you including my post on this thread in your 'mostly irrelevant' comment?