Earthing a bath

[Sickboy]

Hi

I'm installing a new bath and I'm not sure what to do about earthing it. The taps are wall mounted so there is no direct contact between the pipes/taps and bath. The pipes are all earthed.

It is a steel bath so does it need to be earthed?

Thanks

 

[flameport]

It is a steel bath so does it need to be earthed?

No.

Does not require earthing, and doesn't require supplementary bonding either (which is probably what you meant).

 

[Sickboy]

Having dug around some more, it seems I definitely need to earth the bath as it could potentially become live under a fault condition.

 

[Sickboy]

Sorry flameport, you posted while I was writing so I didn't see your post.

Isn't there a chance the bath could become live by accident (very unlikely) and therefore needs to be cross-bonded?

 

[bernardgreen]

Haven't we been here before when a lady standing in the bath was getting electric "tingles" from the pipe work to the shower ?

Personally I would bond the bath to any pipe work and taps that can be reached while in the bath. I fear that a PME provided "earth" to the CPC and therefore pipe work connected to the "earthed" boiler could bounce away from true ground to which the bath may be connected by metal drain pipes or other route ( not necessarily metal but conductive enough to carry enough current to create shock hazard ).

While the chances of both those happening at the same time is very small for the sake of the cost of a few feet of wire and some clamps removal of that risk is worth it. Even a small shock that is not in itself fatal could cause a fall with a significant risk of serious injury or death. fall, hit head, unconscious, head in water, dead by drowning.

 

[flameport]

Isn't there a chance the bath could become live by accident

No more chance of that happening than a metal door handle becoming live, or a metal loo roll holder, or the metal cutlery in your kitchen.

 

[holmslaw]

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[holmslaw]

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[bernardgreen]

Isn't there a chance the bath could become live by accident

No more chance of that happening than a metal door handle becoming live, or a metal loo roll holder, or the metal cutlery in your kitchen.

Yes there is a chance of a metal bath becoming live by accident

Spilt water onto electrics of lighting in room below could create a path for current to reach the bath feet. Not a fatal shock but frightening and possibly followed by consequential injury.

 

[Paul_C]

Personally I would bond the bath to any pipe work and taps that can be reached while in the bath.

As would I. There's a possibility for a potential to exist between the tub and the taps otherwise, resulting in the "tingle" situation, not to mention the chance of a significantly (dangerously) higher voltage appearing between them under fault conditions, since there's almost certainly going to be enough of a leakage path to earth from the bath and associated fittings to result in a considerable shock.

 

[flameport]

Clearly this thread will now degenerate into a useless squabble between people who bothered to look inside a copy of BS7671, and those who read Mr Cockburn's book instead.

 

[bernardgreen]

Clearly this thread will now degenerate into a useless squabble between people who bothered to look inside a copy of BS7671, and those who read Mr Cockburn's book instead.

That is unfair. I have not read Mr Cockburn's book. My views may not agree with the standards that BS7671 set as the minimum to be achieved. But my views are based on 40 years experience and almost as many years of working in "What If" mode and analysis of faults accidents.

 

[Sickboy]

Thanks for your responses guys. I accept both sides of the argument. The chances of the bath becoming live are extremely low but for the sake of a few feet of cable I will get it earthed.

 

[holmslaw]

..

 

[bernardgreen]

Thanks for your responses guys. I accept both sides of the argument. The chances of the bath becoming live are extremely low but for the sake of a few feet of cable I will get it earthed.

Not earthed but bonded electrically to the pipes that can be touched while in the bath. Bonding ensures there is never a voltage difference between the things you can touch at the same time.