earthing in bathroom and kitchen

[guest12345]

My bath, basin, toilet and radioator were originally plumbed in copper. On renewal of the bathroom I picked each pipe up under the floor and fed the new toilet, sink, bath and radiator with plastic (probably about 0.5 metres each).
I also fed off the cold water plastic to the bath to a new stand alone electric shower but in copper.
My question is do I need to bond anything in my bathroom.
Thanks.

If I do the same in the kitchen and feed the sink with plastic from copper under the floor do I need to bond the sink?

Thanks in advance for any help

 

[ColJack]

are there bonds on the water and gas where they enter the property ( or after the meter if they are internal )?

you still need to bond all the earths together in the electrics in the bathroom ( shower to lights to shaver point etc.. ), as well as any metalwork in there ( bath, radiator etc ).. ( unless all your circuits are on RCD's )..

you don't need to bond the kitchen sink anymore.. havent had to for a good number of years now..

 

[Risteard]

And bonding is NOT the same thing as earthing.

 

[ericmark]

Plastic pipes and bonding have been the subject of many papers and there is no simple answer.

The problem is that to earth can cause more of a danger than to not earth and if we touch a live wire and an earth radiator we are going to get more of a shock than if the radiator was not earthed.

However if the radiators were not earthed and for example a standard lamp fell and smashed a bulb and rested with live wire on a radiator then touching a radiator in another room remote from accident you could still receive a shock.

Hence with 17th Edition much of the earthing requirements in a bathroom have been dropped in favour of using a RCD on all circuits.

This is where the problem lies as although the use of a RCD with showers, and outside sockets has been in for many years, the use of a RCD on all bathroom items is new. Even where all sockets are RCD protected the lights are often missed.

701.411.3.3 Additional protection by RCDs
Additional protection shall be provided for all circuits of the location, by the use of one or more RCDs having the characteristics specified in Regulation 415.1.1.
NOTE: See also Regulations 314.1(iv) and 531.2.4 concerning the avoidance of unwanted tripping.

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.

As you can see it is very much dependent on if you electrics meet the latest regulations as to if bonding is required.
Normal is if not sure then bond.

 

[ebee]

I still supp bond anyway if all metal pipework.

Plus - what does the panel think of a lighting circuit non RCDd but feeding the bathroom via an RCD for just that part of the circuit that is feeding the bathroom? Does it comply?

 

[Spark123]

However if the radiators were not earthed and for example a standard lamp fell and smashed a bulb and rested with live wire on a radiator then touching a radiator in another room remote from accident you could still receive a shock.

Hence with 17th Edition much of the earthing requirements in a bathroom have been dropped in favour of using a RCD on all circuits.

Generally speaking on a TN system there isn't a requirement to RCD protect all circuits, just those of the location (bathroom), unprotected concealed cables and socket outlets for general use.
You could quite easily have a table lamp fed from a designated socket on a lighting circuit fed in such a way that it doesn't need RCD protection.

 

[Spark123]

what does the panel think of a lighting circuit non RCDd but feeding the bathroom via an RCD for just that part of the circuit that is feeding the bathroom? Does it comply?

The regulation requires all "final circuits" of the location to have RCD protection as part of the regs for omission of supplementary bonding. To me, this will mean the whole of the final circuit but I have read documents (electrical safety council iirc) saying to the contrary.

 

[ban-all-sheds]

Plastic pipes and bonding have been the subject of many papers and there is no simple answer.

Of course there is.

 

[ebee]

ooh you naughty ban

 

[Risteard]

To me, this will mean the whole of the final circuit but I have read documents (electrical safety council iirc) saying to the contrary.

I'm inclined to agree that your interpretation is the correct one.

 

[ebee]

The problem being the definition of circuit.
If you take a MCB or fuseway on a CU or Distboard as being the origin of that circuit then the whole circuit must comply (be RCDd).
(That's as I prefer too).

However a FCU (say with 3A fuse) would also meet the definition so the bathroom could be seen as having its own final circuit in this respect. and if you do see it this way then it complies. OK I know having a "final circuit" feeding in turn its own "final circuit" is an anomaly but the pedantic could argue either way.

One good point of view that was offered by a person more knowledgeable that I was that of a lighting circuit feeding a few rooms prior RCD and the last little part entering the bathroom has an RCD in order to make it "comply" then an earth fault appearing on one of the other rooms would raise the potential of the cpc entering the bathroom until that fault clears (might be 0.4 or 5.0 seconds) . The RCD would make no difference during that disconnection time period.

That's a sure arguement fo keeping supp bonding alone.

 

[Risteard]

One good point of view that was offered by a person more knowledgeable that I was that of a lighting circuit feeding a few rooms prior RCD and the last little part entering the bathroom has an RCD in order to make it "comply" then an earth fault appearing on one of the other rooms would raise the potential of the cpc entering the bathroom until that fault clears (might be 0.4 or 5.0 seconds) . The RCD would make no difference during that disconnection time period.

Precisely why I would take the view that the entire circuit should be protected, although I acknowledge as you say that the pedantic can indeed argue over the definition of a circuit as per the Definitions in BS 7671.

However, on a Schedule of Test Results I would never dream of listing Fused Connection Units as separate circuits so I think it's an unreasonable assumption to make on their behalf. (Although it does make for good argument!)