boiler earth bonding

[Nostrum]

Hi scooby,

I am a member on there and have been for some time. I am a little confused when you say '

the radiator itself would not be an ECP, as it is only services entering the property which can be classed as this'

As the way I read the regulations is that anything can be ECP especially metallic objects, including structural steel, stainless steel wall coverings in commercial kitchens etc?




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[Scoobydoo]

Hi sambo,

Strictly speaking, you are correct. The definition of an ECP, as you know, is "A conductive part liable to introduce a potential, generally Earth potential, and not forming part of the electrical installation".
However, there is some debate over where and when "extraneous" becomes "exposed". The pipework itself, if isolated from all electrical items, would definitely be considered extraneous, whereas the pipework/radiator fed from a boiler with an earthed chassis which is isolated in some way from the incoming mains or anything else which enters the property such as structural steelwork or pipework could be considered "exposed".
Hope this makes some kind of sense

 

[Nostrum]

As much as anything else in any BS document does! Really then it comes down to testing and common sense to identify/verify. So in actual fact using the example above, the radiator fitted in a bathroom with plastic pipe/fittings could be classed as extraneous (if tested and 22k or less) as you have effectively decoupled it from the boiler/gas/cold water main and MEB? but in reality, if that was the case then it would probably also have a poor path to earth anyway.. :dizzy2:

Thanks

 

[Scoobydoo]

If a rad is connected via plastic only then it will undoubtedly over 23k, under that and there will be a tenuous earth connection somewhere and hence need bonding. That is, unless it is below 1667 ohms and all circuits are RCD protected etc. Gotta love it

 

[zzzjim]

A case for earth bonding , could it reduce likely hood of corrosion , by preventing DC potentials forming ( If there are un-earthed metal parts present in a plastic install )

 

[Howsie]

OMG! I'm off to the pub

 

[mutley racers]

way over my head. So do most of you chaps tell the custard to get an electrician in to check bonding and so on then?