Whirlpool bath connection

[larold]

Just bought a whirlpool bath and am installing it myself. From the pump there is a cable (live, neutral and earth) which I have run through a hole in the connecting wall to a rcd protected socket in the adjacent bedroom, so no problems there but also on the pump there is an earth lead. Where exactly do I attach this to? Is it important, given that there is already an earth in the main cable to the plug?

 

[ericmark]

It will connect to the other equipotential bonding within the bathroom.
415.2.1 Supplementary equipotential bonding shall include all simultaneously accessible exposed-conductive-parts of fixed equipment and extraneous-conductive-parts including, where practicable. the main
metallic reinforcement of constructional reinforced concrete. The equipotential bonding system shall be connected to the protective conductors of all equipment including those of socket-outlets.
701.415.2 Supplementary equipotential bonding
Local supplementary equipotential bonding according to Regulation 415.2 shall be established connecting together the terminals of the protective conductor of each circuit supplying

Class I and Class II equipment to the accessible extraneous-conductive-Parts, within a room containing a bath or shower, including the following:
(i) metallic pipes supplying services and metallic waste pipes (e.g. water. gas)
(ii) metallic central heating pipes and air conditioning systems
(iii) accessible metallic structural parts of the building (metallic door architraves. window frames and similar parts are not considered to be extraneous-conductive-parts unless they are connected to metallic structural parts of the building).
Supplementary equipotential bonding may be installed outside or inside rooms containing a bath or shower, preferably close to the point of entry of extraneous-conductive-parts into such rooms.
Where the location containing a bath or shower is in a building with a protective equipotential bonding system in accordance with Regulation 411.3.1.2, supplementary equipotential bonding may be omitted where all of the following conditions are met:
(i) All final circuits of the location comply with the requirements for automatic disconnection according to Regulation 411.3.2
(ii) All final circuits of the location have additional protection by means of an RCD in accordance with Regulation 701.411.3.3
(iii) All extraneous-conductive-parts of the location are effectively connected to the protective equipotential bonding according to Regulation 411.3.1.2.
NOTE: The effectiveness of the connection of extraneous-conductive-parts in the location to the main earthing terminal may be assessed. where necessary. by the application of Regulation 415.2.2.

 

[larold]

I'm a newbie at all this and it seems a bit double dutch to me. Is there an explanation in laymans terms? I've never heard of equipotential bonding. I had a quick look in the bathroom. There seems to be no other earths connected to anything metal. The water pipes are plastic, but obviously the sink drains are metal and the taps, as well as a towel rail, but there's no earths as far as I can see. Can I run the earth from the bath pump to the light switch (which is located outside the bathroom door) for example?

 

[ericmark]

There is a reason why bathrooms, kitchens, and outdoors need Part P.
If you don't understand it would be dangerous to try to teach you in case some vital point is missed.
You quite obviously need to employ a registered electrician to do the work.
I would never forgive myself if I tried to guide you and it went wrong. One does not get second chances in a bathroom. One is a long time dead!