Bonding Radiators

[Spark123]

ok so both sparkybird and yourself agree that if the circuits are protected by a 30ma rccd then bonding does'nt have to be done

No, read what has been written there.

 

[holmslaw]

..

 

[davelx]

That reg refers to main equipotential bonding and is clear - but you need to read ALL of it.

"shall connect to the main earthing terminal extraneous conducting parts of that installation"

With respect to the equipotential zone of a domestic installation, a central heating system that is wholly contained within that zone is not an extraneous conducting part and therefore does not need to be included in MEB.

 

[holmslaw]

..

 

[Spark123]

The path you mention should already be covered by a MEB to the incoming gas pipe, also the MEB to the incoming water pipe (if pipework is metallic).

 

[JohnD]

...liable to introduce a potential...

So where do you think the radiator is going to introduce it from?

 

[jaguar1]

"If the piping is plastic you do not have to bond them.

If the piping is copper then link all the pipes around the boiler together using earth clamps and 4mm earth cable."

The reg is 413-02-02, it quite clear, unambiguous, doesnt mention bathrooms, kitchens or special locations.

So do you run the 4mm cable back to the MET or connect to the earth terminal of the boiler circuit or just connect. out the pipes and boiler

 

[RF Lighting]

clicky

 

[jaguar1]

Thanks , So it says not to run the 4mm bonding wire to the MET but do you bond it to the light circuit or shower or the imersion heater circuit of the bathroom.

Or are you relying on the main water pipe being bonded as it enters the house and there are no plastic joints in the pipes from where it enters the house and the bathroom / airing cupboard.

 

[RF Lighting]

No.

You are not installing supplementary bonding to earth all the metalwork in your bathroom. You are installing it so that in the event of a fault, all exposed metalwork remains at the same potential, be it earth potential, mains potential, or anywhere inbetween.

 

[ban-all-sheds]

Thanks , So it says not to run the 4mm bonding wire to the MET but do you bond it to the light circuit or shower or the imersion heater circuit of the bathroom.

FFS.

i know the barhroom rad should be bonded to the light circuit

And the shower circuit, if there is one.

And possibly the towel rail circuit.

And possibly the grid or sheathing of an underfloor heating circuit.

It is supplementary equipotential bonding, not earthing.

It is there to bond all extraneous-conductive-parts in Zones 1, 2 & 3 to the cpcs of all the circuits supplying Class I and Class II equipment in Zones 1, 2 & 3.

 

[jaguar1]

So if were trying to earth metalwork why does the regs say do not bond to the met ?

 

[RF Lighting]

You are not trying to earth metalwork.

Did you not read my last post?

 

[jaguar1]

Yes i did , but do you then connect the pipes boiler to your cpc of your lights and imersion etc in the bathroom even if the airing cupboard is next door to the bathroom.

I am halfway through the 17 iee regs at college but still find all this confusin !!!!

 

[JohnD]

You originally asked

Do you bond a single rad ... .

Then I thought you were talking about bathrooms

Now you're asking about boilers

I am assuming your boilers are not in bathrooms

Your course will probably not tell you any regulations about boilers (because there aren't any)

However, people who work on boilers, and boiler manufacturers, say you should bond all the pipes (water and gas) and the CPC of the boiler supply. You might wonder why, since they are all fastened to the iron boiler. The reason, I understand, is that the boiler fitter might remove the boiler, or disconnect it from its pipes for servicing or replacement, and he then wants all the pipes to be at the same potential because he might touch one pipe with one hand, and another pipe with the other hand. very similar to the method you will learn for Bathroom Supplementary Bonding. Because boilers and there pumps are full of water, and electrically controlled, there is a fair chance of a potential being introduced under fault conditions (they often trip RCDs after a leak).