Bonding....

[Southcoast2015]

Yeah gas is done because it enters house near electricity.

But you've got the rest spot on....

I know it really should be bonded but as I've already said the only piece that can be considered extraneous is about a 6ft length that is boxed in, the rest of the pipe installation is broken up in various places with plastic fittings - unless someone was using something faulty on an extension lead, crawling around on the floor with their hand reached up inside the boxing in (not sure you'd actually be able to fit a hand in there) then the chances of a person coming into contact with something live and a potential difference due to that pipe is almost certainly never going to happen!

 

[Rob_the_rich]

Yeah gas is done because it enters house near electricity.

But you've got the rest spot on....

I know it really should be bonded but as I've already said the only piece that can be considered extraneous is about a 6ft length that is boxed in, the rest of the pipe installation is broken up in various places with plastic fittings - unless someone was using something faulty on an extension lead, crawling around on the floor with their hand reached up inside the boxing in (not sure you'd actually be able to fit a hand in there) then the chances of a person coming into contact with something live and a potential difference due to that pipe is almost certainly never going to happen!

The only time I think it might be touched is if there is a huge leak, the place is flooded, the householder/plumber is soaking wet, he/she leans on a radiator to access the stopcock. Water gets into a fitting elsewhere and causes a fault current, there is no rcd protection on that circuit (or rcd faulty) the voltage rises on the equipotentially bonded radiator, there is a potential difference between the rad and the stopcock....Unlikely I know, but even small earth leakage currents can give you a belt. And an rcd won't trip if current is flowing from the radiator to the stopcock through you.

 

[Southcoast2015]

I understand your thoughts but again there is no radiator anywhere near it, it is completely isolated (in a none electrical sense)

 

[NozSpark]

This needs bonding, end of, IMHO

Can you route the cable up the outside of the house through the loft, and then down through an airing cupboard (or something)?

 

[Andy™]

regulations clearly state its to be bonded. if you dont want to do that, then thats upto you, just make a note on EIC that you have deviated from the regulations and be prepared to stand up in court to defend your actions if there is a problem in the future

 

[binky]

I would cross bond boiler and make note on CU to be careful of any modifications. If the 6ft of pipe is basically boxed in and not accesible there isn't really a risk especially if there is poor continuity on pipes due to plastic speedfits

regulations clearly state its to be bonded. if you dont want to do that, then thats upto you, just make a note on EIC that you have deviated from the regulations and be prepared to stand up in court to defend your actions if there is a problem in the future

they aren't regulations they are recommendations, but I think it would be justifiable in this case not to bond at the stopcock.

Failing that advise customer it should be done in writing, legal arse covered

 

[Southcoast2015]

I'm only doing minor work so there is no EIC to fill out it was mostly an observation as even when doing small jobs I keep my eye out for anything else that may cause the customer a problem in the future and offer advice to suit.

I fully understand that this should be bonded and also fully aware that BS7671 states this but........

I cannot see that unless under almost impossible circumstances this particular pipe is ever going to cause a problem - it's almost a perfect exception to the rule in my opinion.

I am however thankful to those who have replied so far, it's always helpful to hear other people's views on things.

This needs bonding, end of, IMHO

Can you route the cable up the outside of the house through the loft, and then down through an airing cupboard (or something)?

No it's partly beneath a bedroom and a tiled bathroom/wet room, it would have to be a floorboards up jobby and try and Rod it over and even then it may be a section cut out it downstairs ceiling to pull it through.

 

[binky]

do note observation on minor works either way.

I've been faced with similar problems before, soild wood flooring / tiles/ concrete floors etc etc. Plastic pipe fittings are a nightmare, the only way of dealing with these is to bond jumper leads across the joins. So I work on the basis that central heating, baths, taps etc etc are all connected back to boiler where you can pick up gas, cold water and electric. If there is a conductive path to be found then it almost certainly runs through the boiler. There's more copper in pipes than a 10mm bond cable, ergo a good conductive path can be had to whole house in theory. You should test to be sure.

 

[Southcoast2015]

I would cross bond boiler and make note on CU to be careful of any modifications. If the 6ft of pipe is basically boxed in and not accesible there isn't really a risk especially if there is poor continuity on pipes due to plastic speedfitsThere's not continuity at all mate. From what I've seen there isn't a water pipe in the house (apart from CH) that hasn't had plastic fittings stuffed into it.

 

[binky]

then I see no point. I have a strong dislaike of plastic elbows after nearly getting killed whilst working under a bath - they allow pipes to be live wihout blowing fuses. That in turn brings us back to continuity paths, if there isn't one......

I also know of a local sparky who died after grabbing  a live cable and falling against a radiator that did have a good earth path

 

[Southcoast2015]

CH pipes are bonded, bathroom water pipes both hot and cold are bonded which is why I'm assuming this has all been done at boiler, power shower comes straight off water main after 2 plastic Tee pieces and the pipe to shower itself is also plastic.

So I'd have to agree with you, no one can touch box in pipe, it's insulated from any other pipe through plastic fittings and if it's cross bonded to gas at the boiler then that sorts that end of the pipe.

 

[Essex1]

Did you remove the gas bond when you tested the water pipe to see if it was extrenous?

 

[Southcoast2015]

Did you remove the gas bond when you tested the water pipe to see if it was extrenous?

No I didn't actually...

 

[Essex1]

So that 1 ohm reading could be the reading between the MET and the water pipe through the gas bonding and pipe work.

 

[binky]

I would describe the plastic couplers as having  a very high resistance rather than being insulated - I got called to the bath of doom becuase of a 'popping noise' ie the electric was occasionally arcing through the water.

The whole point of bonding is to bring all extrenuos earth paths to a safe touch voltage under fault conditions, which on a re-wireable fuse is 5secs (in theory). This means if you were touching a radiator with good earth path and a faulty appliance the potential difference between good earth path and appliance is less than 50V and subsequent fault current flowing through you is insufficent to kill. Now if you can't touch incoming water supply and faulty appliance, you are 'safe', and if high resistances exist on all pipework over about 500 ohms, then a/ bonding stopcock is useless, b/ current flow would in the region of 48mA at 500Ohm, less if higher resistance exists.

 

[Doc Hudson]

I'm only doing minor work so there is no EIC to fill out it was mostly an observation as even when doing small jobs I keep my eye out for anything else that may cause the customer a problem in the future and offer advice to suit.

I fully understand that this should be bonded and also fully aware that BS7671 states this but........

I cannot see that unless under almost impossible circumstances this particular pipe is ever going to cause a problem - it's almost a perfect exception to the rule in my opinion.

I am however thankful to those who have replied so far, it's always helpful to hear other people's views on things.

No it's partly beneath a bedroom and a tiled bathroom/wet room, it would have to be a floorboards up jobby and try and Rod it over and even then it may be a section cut out it downstairs ceiling to pull it through.

You will still have a MWC to fill out that has bullet points for; details of departures, permitted exceptions, and comments on existing installation including earthing and bonding, making specific note of regulation 132.16.  All you need to do is refamiliarise yourself with the information needed for the certificate, decide what you are going to put and how if needed you can justify your decisions, also make sure you have sufficient insurance in case the worst does happen and your signed certificate comes up as evidence  during investigations. There have been cases of obscure sets of events occurring and persons receiving serious or fatal electric shock. At the end of the day it is your call and your neck on the line. Some members here may take one course of action others take a different one. Whatever you do make sure you have sufficient documented tests to back up your decision.

Doc H.

 

[Southcoast2015]

So that 1 ohm reading could be the reading between the MET and the water pipe through the gas bonding and pipe work.

Be nice if it was...

 

[NozSpark]

OK,,, so another option might be to replace all the speedfit elbows, tees etc with brass fittings and bond at a more accessible place

 

[binky]

if you thnk about it, that makes the place more dangerous

 

[Southcoast2015]

You will still have a MWC to fill out that has bullet points for; details of departures, permitted exceptions, and comments on existing installation including earthing and bonding, making specific note of regulation 132.16.  All you need to do is refamiliarise yourself with the information needed for the certificate, decide what you are going to put and how if needed you can justify your decisions, also make sure you have sufficient insurance in case the worst does happen and your signed certificate comes up as evidence  during investigations. There have been cases of obscure sets of events occurring and persons receiving serious or fatal electric shock. At the end of the day it is your call and your neck on the line. Some members here may take one course of action others take a different one. Whatever you do make sure you have sufficient documented tests to back up your decision.

Doc H.

Thanks for reply - I have insurance, and yes I fill out plenty of MWC, it was really just to get other people's views on it as you can sometimes be a bit narrow minded in thought when working alone or completely go off on a tangent.