Electrical pt 17 regulation question

[platforminc]

Hi,

I am here to ask a question about re-wiring a house, if the bath is plastic does it still need earth bonding attached to it.

There is earth bonding on all the pipes connected to the boiler about 4/5, someone said to me that since it has bonding on those boiler pipes, then its no longer required to bond individual items seperately.

Please confirm.

 

[rjm2k]

What would you attach it to on the plastic bath? Are you doing the re-wire?

 

[viewer]

Simple answer to the bath is no because you cannot bond a plastic item electrically as plastic will not conduct electricity. The need for bonding for other items in the bathroom, such as taps, shower plumbing etc (which may or may not involve the earth) needs working out according to actual needs at the location. There are lots of threads on this forum, but before you try to work out the electrical connections needed, you need to know the material for other pieces, e.g. are all the pipes copper?

 

[riveralt]

Hi, I am here to ask a question about re-wiring a house, if the bath is plastic does it still need earth bonding attached to it.
There is earth bonding on all the pipes connected to the boiler about 4/5, someone said to me that since it has bonding on those boiler pipes, then its no longer required to bond individual items seperately.
Please confirm.

Why not make use of wiki...
//www.diynot.com/wiki/electrics:speclcn:supbond17th
Plumbers do have a penchant for bonding every copper pipe they see even if they don't need to. So don't be guided by the actions of others - they might be wrong.
If you do intend to rewire your house yourself, supplementary bonding is but one of many questions you will need answers to - and if, from your initial question, you think electricity will flow through plastic then perhaps you need to get someone in to help you.

 

[JohnW2]

... and if, from your initial question, you think electricity will flow through plastic then perhaps you need to get someone in to help you.

That could well be true. Mind you, at least historically, potential DIYers were not unique in having problems in this area. I recall, many many years ago, seeing a plastic bath on the underside of which the manufacturer had kindly moulded an 'earthing terminal'!

Kind Regards, John

 

[platforminc]

The house was re-wired, all pipes are plastic and I know plastic wouldnt be a conductor like say copper or metal.

There are copper pipes underneath the floorboards, they rise up just halfway by the pedestral wash hand basic, then flexi pipe to feed the taps.

Also, what about the taps in the bath and also the washhand basin, they are not plastic by the way.

 

[Aragorn84]

all pipes are plastic

There are copper pipes underneath the floorboards

 

[riveralt]

The house was re-wired, all pipes are plastic and I know plastic wouldnt be a conductor like say copper or metal.
There are copper pipes underneath the floorboards, they rise up just halfway by the pedestral wash hand basic, then flexi pipe to feed the taps.
Also, what about the taps in the bath and also the washhand basin, they are not plastic by the way.

You seem to be asking the same question - have you looked at the wiki page?
Click on the link to the NICEIE document that gives the information in graphical form as well.

You now say your house has been rewired - rather than the impression that you were going to rewire it.
Once you have read the articles you will be able to check your electrical installation and satisfy yourself regarding the safety or not of your washbasin taps etc.
Here is a more direct link; though you should read the wiki articles as well because the link is from 2001.
//www.diynot.com/wiki/electric...l_bonding:supplementary_equipotential_bonding

 

[platforminc]

If I am right, point number 3 means that bathroom bonding wouldn't be required in my case. As I am not a sparkie, can someone kindly confirm my thinking.



All circuits comply with the requirements for disconnection times
All circuits are RCD protected by a 30mA device maximum
All extraneous conductive parts in the location are effectively connected to the protective equipotential bonding.

 

[JohnW2]

If I am right, point number 3 means that bathroom bonding wouldn't be required in my case. As I am not a sparkie, can someone kindly confirm my thinking.
All circuits comply with the requirements for disconnection times
All circuits are RCD protected by a 30mA device maximum
All extraneous conductive parts in the location are effectively connected to the protective equipotential bonding.

I'm not sure what you mean by 'point number 3' but, as you presumably already know, if those three (all three) conditions are satisfied in a bathroom, then there is no requirement for any supplementary bonding in that bathroom.

Kind Regards, John

 

[JACKC]

As pointed out, to omit bonding you need to prove all 3.
Point 3 is carried out using continuity tester to ensure that all metal parts in the bathroom zones are connected to the main earth terminal via the water bonding conductor in your CU. If no continuity then you probably have plastic fittings interrupting the copper pipe or a mish mash of copper/plastic pipework. You will need to bond in the bathroom if no continuity. You will need to meet all 3 conditions.

 

[JohnW2]

As pointed out, to omit bonding you need to prove all 3. ... Point 3 is carried out using continuity tester to ensure that all metal parts in the bathroom zones are connected to the main earth terminal via the water bonding conductor in your CU. If no continuity then you probably have plastic fittings interrupting the copper pipe or a mish mash of copper/plastic pipework. You will need to bond in the bathroom if no continuity. You will need to meet all 3 conditions.

I think that's potentially misleading. The third of those requirements ('point 3'?) relates only to extraneous-conductive-parts in the bathroom. From what we've been told (about plastic pipework etc.), it's quite possible that there are no extraneous-c-ps in the bathroom, in which case there would be nothing to satisfy as far as that third condition is concerned.

Kind Regards, John

 

[EFLImpudence]

Point 3 is carried out using continuity tester to ensure that all metal parts in the bathroom zones are connected to the main earth terminal via the water bonding conductor in your CU.

True.

An Insulation Test should be carried out first between parts and the MET.
If MegaOhm reading recorded then MUST NOT BE BONDED whether RCD protected or not.

If low IR, that is 0.00MΩ, then a continuity test.
If more than 23 kΩ then MUST NOT BE BONDED whether RCD protected or not.

If no continuity then you probably have plastic fittings interrupting the copper pipe or a mish mash of copper/plastic pipework.

True.

You will need to bond in the bathroom if no continuity.

NO. If NO continuity then the part MUST NOT BE BONDED whether RCD protected or not.

You will need to meet all 3 conditions.

True but then testing BETWEEN parts NOT excluded by the above is required to determine if supplementary bonding is required.

If R < 50 / Ia then supplementary bonding is not required anyway.
(Ia = 5 x the highest circuit OPD rating of the location)

 

[JohnW2]

Point 3 is carried out using continuity tester to ensure that all metal parts in the bathroom zones are connected to the main earth terminal via the water bonding conductor in your CU.

True.
An Insulation Test should be carried out first between parts and the MET.
If MegaOhm reading recorded then MUST NOT BE BONDED whether RCD protected or not.
If low IR, that is 0.00M&#937;, then a continuity test.
If more than 23 k&#937; then MUST NOT BE BONDED whether RCD protected or not.

Indeed, but lest any readers are confused as to why that is the case ... only 'extraneous-conductive parts' need supplementary bonding, and those test results you mention would indicate that the parts in question are not extraneous-c-ps. That being the case, supplementary bonding is not required and many people would go further (like you) and say that it should not be installed (because it actually increases risks, rather than reduce them).

Kind Regards, John

 

[EFLImpudence]

Point 3 is carried out using continuity tester to ensure that all metal parts in the bathroom zones are connected to the main earth terminal via the water bonding conductor in your CU.

True.
An Insulation Test should be carried out first between parts and the MET.
If MegaOhm reading recorded then MUST NOT BE BONDED whether RCD protected or not.
If low IR, that is 0.00M&#937;, then a continuity test.
If more than 23 k&#937; then MUST NOT BE BONDED whether RCD protected or not.

Indeed, but lest any readers are confused as to why that is the case ... only 'extraneous-conductive parts' need supplementary bonding, and those test results you mention would indicate that the parts in question are not extraneous-c-ps. That being the case, supplementary bonding is not required and many people would go further (like you) and say that it should not be installed (because it actually increases risks, rather than reduce them).

Yes, good points.

Should I include my saying? I like it.

We bond parts because they are already earthed (extraneous) .

It would be better if they weren't but some are