Bonding Location

[Smugley]

Just wondering if there is a consensus on this or if it is another divided issue.

When selecting a location to main bond say the incoming water pipe, you need to be within 600mm of entry to the building, but the clamp must be accessible for inspection. Sometimes I choose one or the other requirements to take precedence. For example in Victorian terraces where typically the water supply enters under the front steps and runs at ground level and pops up in the rear kitchen. Do you bond within 600mm of the pipe's entrance into the building structure, under the front doormat, making the clamp difficult to get to, or bond when the pipe enters the living space? Couldn't guarantee this won't be after any t-joints which may be there now or be added in future.

 

[telectrix]

all depends on where the stop tap is. that should be in an accessible location.

 

[nick611]

do it under the floor and note it on the sheet. it assesable if you lift the boards

 

[domestic spark]

do it under the floor and note it on the sheet. it assesable if you lift the boards

but what if some one laminates, or has fitted carpets? is this really accessable really?? would you want someone ripping your flooring up just to check earth bond.

i would do it upon point of entry in kitchen smugley!

 

[SPARTYKUS]

It doesn't have to be 600mm from entry. It says something like "or if not possible as near as is practicable" ......

 

[domestic spark]

It doesn't have to be 600mm from entry. It says something like "or if not possible as near as is practicable" ......

where practicable the connection to the gas, water, ect service should be within 600mm of the service meter, or at the point of entry to the building if the serive meter is external and must be on the consumers side before any branch pipework and after any insulating section in the service

 

[domestic spark]

hope this clears things up for you smugley

 

[Smugley]

Yeah, clear as mud! Heh heh! Thanks for the comments. It's as I suspected, still a difficult question. I think it's safe to say it would be unlikely anyone would branch off the water supply before the main stopcock, so in the case I have in mind I will go for under the kitchen sink. Last one I did was easy - access panel put in specially by builders under the front door mat.

 

[Geordie Spark]

Here's one for you all to consider:

The water main is 25mm plastic (Alkathene) and enters the building vertically through the concrete floor of the utility room.

It rises approx. 300mm from the floor & is then fitted with a brass stoptap. From the stoptap, it rises in 22mm copper into the ceiling void - a length of a cople of metres max, - where it is attached to 22mm plastic pipe.

This plastic pipe runs to all the taps, boiler & other water outlets in the house.

The question is; does the vertical run of 22mm copper pipe need to be bonded?

 

[malcolmsanford]

Is it an extraneous conductive part? If it is then yes you would need to bond it, if it isn't then no

 

[DurhamSparky]

The water main is 25mm plastic (Alkathene) and enters the building vertically through the concrete floor of the utility room.

It rises approx. 300mm from the floor & is then fitted with a brass stoptap. From the stoptap, it rises in 22mm copper into the ceiling void - a length of a cople of metres max, - where it is attached to 22mm plastic pipe.

This plastic pipe runs to all the taps, boiler & other water outlets in the house.

my honest opinion!!

NO!!! you would be inducing a path to that little piece of copper thats fitted and INCREASING The likely hood of a shock!

 

[domestic spark]

my honest opinion!!

NO!!! you would be inducing a path to that little piece of copper thats fitted and INCREASING The likely hood of a shock!

Agree I would not bond!

 

[SPARTYKUS]

Is it an extraneous conductive part? If it is then yes you would need to bond it, if it isn't then no

Thats the answer. And only way to know for sure is to test it (IR tester, Meg Ohms, other end to known earth, if greater than 0.02M Ohms or 20,000 Ohms, no bonding required. If less, yes bond it)

 

[Geordie Spark]

my honest opinion!!

NO!!! you would be inducing a path to that little piece of copper thats fitted and INCREASING The likely hood of a shock!

That's what I thought, but I asked the question at the college where I was taking the 17th Edition course and half the class of 20 said "yes" & the other said "no".

The lecturer said "no" & when he went off for his coffee break he asked the other lecturers and again, the opinion was divided.

 

[Geordie Spark]

Thats the answer. And only way to know for sure is to test it (IR tester, Meg Ohms, other end to known earth, if greater than 0.02M Ohms or 20,000 Ohms, no bonding required. If less, yes bond it)

Many thanks for that.

In the event, I fitted the bonding clamp to the pipe & ran the 10mm yellow/green cable from the MET to it but left it disconnected from the clamp on the pipe.

When the inspector arrived to complete the EIC, I explained to him that the copper pipe was connected to plastic at both ends & asked him if he wanted the bond connected or not. Without any testing as you describe, he said he did so I connected it.

 

[malcolmsanford]

Many thanks for that.

In the event, I fitted the bonding clamp to the pipe & ran the 10mm yellow/green cable from the MET to it but left it disconnected from the clamp on the pipe.

When the inspector arrived to complete the EIC, I explained to him that the copper pipe was connected to plastic at both ends & asked him if he wanted the bond connected or not. Without any testing as you describe, he said he did so I connected it.

That is interesting, Can I ask what inspector it was , was it NICEIC or NAPIT, becasue I know it's a guide only but the OSG on page 29 Section 4.4 is quite adamant about bonding plastic pipes. There is a great chance that as the incomer is plastic and then plastic to where joints are on the boiler that that small section of pipe would certianly not be an extraneous conductive part, and not need bonding, but just to say bond it without checking is a little suprising.

 

[Geordie Spark]

That is interesting, Can I ask what inspector it was , was it NICEIC or NAPIT, becasue I know it's a guide only but the OSG on page 29 Section 4.4 is quite adamant about bonding plastic pipes. There is a great chance that as the incomer is plastic and then plastic to where joints are on the boiler that that small section of pipe would certianly not be an extraneous conductive part, and not need bonding, but just to say bond it without checking is a little suprising.

I agree with you, but after the controversy I caused when I asked the question at college, I thought I'd cover myself by running the cable in & not connecting it until told to do so (or not) rather than not run it in only to be told when the job was finished that it was needed.

The inspector was arranged by the customer - a builder - who was building this 5 bed self-build for himself.

During the whole of my time on site, I only met this inspector twice and honestly don't know anything about him.

I was surprised that he completed the inspection & test in less than 2 hours though & charged £90, I was expecting him to be there for half a day.

 

[malcolmsanford]

Lol I think we maybe going down the road here of a sparks/inspector signing off someone elses work. ...................... whoever it was perhaps is not a good an inspector as the builder thought.

 

[Geordie Spark]

Lol I think we maybe going down the road here of a sparks/inspector signing off someone elses work. ...................... whoever it was perhaps is not a good an inspector as the builder thought.

Yes ... quite !!

 

[IQ Electrical]

Many thanks for that.

In the event, I fitted the bonding clamp to the pipe & ran the 10mm yellow/green cable from the MET to it but left it disconnected from the clamp on the pipe.

When the inspector arrived to complete the EIC, I explained to him that the copper pipe was connected to plastic at both ends & asked him if he wanted the bond connected or not. Without any testing as you describe, he said he did so I connected it.

Just about sums it up really, he had no idea what he was looking at....

This is from Paul Cook at the IET and shows that the pipe described can't be an extraneous-conductive part.

Everyone knows that water and electricity do not
mix, that the risk of electric shock is greater when
there is water around. They know that the risk and
severity of an electric shock is increased as a result
of the presence of water. This may be the reason
for the concern that water in plastic pipes may
conduct electricity and that bonding is required.
Because of this, the IEE commissioned the
Electrical Research Association to carry out
measurements of the electrical conductivity of
water in plastic pipes.
The ERA tests confirm that tap water in a plastic
pipe is a poor conductor of electricity. One metre
of 15 mm diameter plastic pipe filled with tap
water from Leatherhead where the ERA are based,​

has a resistance of 100,000 Ohms. This one metre of

pipe will restrict currents to less than fatal values
and of course in practice, there would be many
metres of pipe between metal items of plumbing
equipment and earth.​

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