Plastic Water main with copper throughout.

[rattlehead85]

Was called to a job yesterday where a company had completed an EICR on a house fed via a plastic water main with internal plumbing done completely in copper. They had put a c2 observation code for a lack of main protective bonding to the water. The customer had shown me the EIC cert she had been given by the original company who had completed a rewire on her property.
Disconnecting the earthing conductor at the intake position and completing an IR test to the internal stopcock on the water gave me a reading of 0 megohms. To me this has indicated that somewhere within this installation the copper pipework is earthy and deemed extraneous and does warrant a main bond. I did think this could be gaining a reading through the boiler gas connection (which is bonded) I am leaning on the side of advising the client to get the original contractor back to sort this. Opinions on this before doing so would be appreciated.

 

[spark 68]

Re: Plastic Water main with coper throughout.

What was the actual reading back to the MET ?, not the 0 Mohm one though, the actual R2 for want of a better term.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

.09 mate. Today i have been told that the original contractor had returned and told the client the water is already bonded as the gas is done and feeds the water through the heating system pipework. Apparently the water according to them didn't require a direct bond as the incomer is plastic. I pointed out this is incorrect and backed it up with the use of the osg but now have been accused of trying to source work.!!

 

[spark 68]

Re: Plastic Water main with coper throughout.

.09 mate. Today i have been told that the original contractor had returned and told the client the water is already bonded as the gas is done and feeds the water through the heating system pipework. Apparently the water according to them didn't require a direct bond as the incomer is plastic. I pointed out this is incorrect and backed it up with the use of the osg but now have been accused of trying to source work.!!

If the incomer is plastic then it is not introducing an Earth potential from outside at that point, my next move is to see how low the reading actually is back to the met, and if it is around the suggested 0.05 mark as per GN3 I assume it is bonded via the gas (boiler) so long as I can see and verify the gas bond.

I usually look to see if it is below say about 0.1 or above 23k to decide if it needs it or not, I usually look at the approximate length of the run and see if it matches the expected R2 value as per the tables.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

Well i verified the gas bond as compliant. The readings i got indicated to me that the water was extraneous. What i cant prove is if the water really is getting its earth through the gas or wether there is an inaccessible pipe concealed behind panelling which may be making contact with earth which would deem the service to be bringing an earth potential into the property within its own right. I'm thinking that due to this possibility a main protective bond at the stopcock position would be desirable.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

Im beginning to think this is what the company doing the EICR was thinking and that the rewire firm don't really know so they are using the fact they put an earth on the ga s as their --- covering strategy.

 

[Engineer54]

Re: Plastic Water main with coper throughout.

All depends if the metal water pipe after the stopcock enters the slab again, or in the case of blocks of flats passes bare through, or in the floor slabs or run buried in coluums, where they will almost certainly become extraneous..

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

The stopcock is under the kitchen sink it then bends and runs clipped to the wall into a service void which i cannot access as it is tiled and decorated. This service void runs up to the bathroom directly above where i can see a water pipe and a metal soil pipe in a cupboard which incidentally have no visible signs of bonding...

 

[spark 68]

Re: Plastic Water main with coper throughout.

I would also disconnect the Gas bond at the MET and measure across the gas and water pipes.

On normal houses where the incomer is plastic , unless I see evidence of either an outside metallic pipe (garden tap etc.) or an outbuilding with a water supply, it is fairly safe to say that it won't be bringing in an Earth potential from outside.

The metal soil pipe would need further investigation though.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

The soil pipe is most def extraneous. I verified this back to the earthing conductor and needs bonding. What i also considered was the possibility that somebody has cross linked the pipes behind the panel along with the soil pipe therefore this would explain why i get a reading off the water at the stopcock point. As i said im leaning towards asking for a bond to be placed at the stopcock as the circumstances relating to this are telling me that for whatever reason the water is earthy. Question is would there be any adverse effects from bonding the water independently along with the soil waste.

 

[spark 68]

Re: Plastic Water main with coper throughout.

. Question is would there be any adverse effects from bonding the water independently along with the soil waste.

No adverse effects, as in this case it is already effectively bonded via the gas by that reading, apart from the difficulty of routing the MPB that is

You could always add it as near as practicable if you feel it needs it.

 

[Geordie Spark]

Re: Plastic Water main with coper throughout.

Well i verified the gas bond as compliant. The readings i got indicated to me that the water was extraneous. What i cant prove is if the water really is getting its earth through the gas or wether there is an inaccessible pipe concealed behind panelling which may be making contact with earth which would deem the service to be bringing an earth potential into the property within its own right. I'm thinking that due to this possibility a main protective bond at the stopcock position would be desirable.

You can if you dis the gas supply from the boiler.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

You can if you dis the gas supply from the boiler.

Agreed [emoji1][emoji1][emoji1] prob is i aint gas safe to do so and im damn sure i aint putting my --- in court over a job which i was only asked to give an opinion on.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

Im going to compile a covering letter outlining the reasons why i feel the company who did the EICR are correct in saying the water requires a main bond. Using the OSG and BYB i can show why a main bond would be desirable. The findings are relatively inconclusive so in this situation i would suggest bonding the water as a bond to the soil is most definitely absent and needed and a link onto the water at this point is relatively easy to do. The fact that adding a bond will not incur a hazardous condition makes it sensible to do the job and eliminate the uncertainty in the process.[emoji106]

 

[davesparks]

Re: Plastic Water main with coper throughout.

If the results of your test on the water main have been affected by the main bond to the gas then you have not carried out the test correctly.

Isolate the installation, then disconnect the earthing conductor from the MET (or remove test link). You then test between the incoming earth and the suspected extraneous part.

I'm not surprised you have been accused of trying to get work by unscrupulous means, a plastic water main which feeds surface clipped installation pipework is unlikely to be extraneous.

 

[davesparks]

Re: Plastic Water main with coper throughout.

, my next move is to see how low the reading actually is back to the met, and if it is around the suggested 0.05 mark as per GN3 .

That 0.05 is the suggested max resistance between a pipe and the electrical connection of the earthing clamp, NOT the resistance of the bonding conductor!

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

Can you please read through the whole thread. You'll find that that is exactly what i did!!

 

[davesparks]

Re: Plastic Water main with coper throughout.

Can you please read through the whole thread. You'll find that that is exactly what i did!!

I did, you said you thought the low reading may be due to the main bond on the gas. Therefore you must have carried out the test incorrectly for it to be possible for the gas bond to influence the test result.

 

[spark 68]

Re: Plastic Water main with coper throughout.

That 0.05 is the suggested max resistance between a pipe and the electrical connection of the earthing clamp, NOT the resistance of the bonding conductor

I know, in domestic though you would need a bloody long run to really exceed that my much if it was 10mm, I did say to take into account and check against the tables.

And it is between "points" not necessarily the connection between the clamp and a pipe.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

I didn't just say it was extraneous for the sake of it and if you had bothered to read the thread you'd see i was asked for an opinion only not price for any potential work!!

 

[davesparks]

Re: Plastic Water main with coper throughout.

I didn't just say it was extraneous for the sake of it and if you had bothered to read the thread you'd see i was asked for an opinion only not price for any potential work!!

I did read the thread.
You said you thought the reading may have been influenced by the gas bond, if this is the case then the test has been carried out incorrectly.

What is the 0.9 you mentioned earlier? Is it ohms, kilohms or megohms?

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

I did, you said you thought the low reading may be due to the main bond on the gas. Therefore you must have carried out the test incorrectly for it to be possible for the gas bond to influence the test result.

Hang on.... in the thread it clearly says i removed the main earth and tested between the earthing conductor and the metal pipework by the stopcock. So how would the gas bond influence the test if it aint connected to the main earthing conductor during the test?? Where the gas issue comes into it as was clearly pointed out was the fact that the water reading could be because of a connection through the boiler onto the gas pipe which in itself is extraneous so clearly you haven't read it correct.

 

[davesparks]

Re: Plastic Water main with coper throughout.

In post one you said you thought the gas bond may have affected the test result. The only way it could affect it is if it was connected during the test!

Now what units is that 0.9 in?

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

The 0.9 ohm value was attributed to the gas bond test i carried out between the m.e.t and the gas bond with the bond disconnected at the gas meter position. This was completed to confirm the gas bond was actually continuos.
How do you expect me to separate the gas pipework from the water on a heating system??

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

Davesparks im sure you have unintentionally misinterpreted what i am trying to point out here.

 

[spark 68]

Re: Plastic Water main with coper throughout.

I actually thought the R2 reading of 0.9 was from the water pipe just after the stop tap in copper back to the MET with the gas bond connected.

As per GN3 relates to the 0.05 reading between "points" not necessarily between the clamp and the pipe, what I have done before in this situation is to measure between the disconnected gas bond at the CU and a nearby water pipe, or the wander lead back from the same bond disconnected at the CU to the copper part of the of the incomer. whatever is easier in a given situation.

 

[davesparks]

Re: Plastic Water main with coper throughout.

I don't expect you to disconnect the gas and water from the boiler manifold. But if the water main has become extraneous due to its permanent connection to the gas main at that point then in my opinion the water pipework is then extraneous.
Is the incoming gas pipe plastic or metal? Does the gas pipe produce exactly the same reading when tested for extraneous?

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

I carried out the tests correctly, the fact that i got 0 megohms on the IR test as i mentioned in post 1 between the water stopcock and the main earth with it removed from the MET proves its extraneous by whatever means.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

I don't expect you to disconnect the gas and water from the boiler manifold. But if the water main has become extraneous due to its permanent connection to the gas main at that point then in my opinion the water pipework is then extraneous.
Is the incoming gas pipe plastic or metal? Does the gas pipe produce exactly the same reading when tested for extraneous?

gas is metal, the gas has a bond which i confirmed on a separate test. The gas is extraneous. As i said i cant prove the water is getting its extraneous nature because of the connection through the boiler manifold or if it is because behind the tiled panel it is either linked to the soil stack or it runs back to ground. Hence why i was saying it would be desirable to run a bond to the water.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

The whole point of this thread was to see what others would decide faced with this situation baring in mind i was a third party asked to give an opinion on an EIC and a subsequent EICR carried out by a different contractor.

 

[spark 68]

Re: Plastic Water main with coper throughout.

Okay if we assume the gas pipe is extraneous and is bonded correctly at the correct point at the incomer to mitigate that fact, then how does the water become extraneous just by being earthy to the gas pipe via the boiler which is already bonded ? it cannot become extraneous via the plastic incomer, it is only earthy from inside the equipotential zone, unless as E54 said it runs back through zone, concrete slab etc.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

Okay if we assume the gas pipe is extraneous and is bonded correctly at the correct point at the incomer to mitigate that fact, then how does the water become extraneous just by being earthy to the gas pipe via the boiler which is already bonded ? it cannot become extraneous via the plastic incomer, it is only earthy from inside the equipotential zone, unless as E54 said it runs back through zone, concrete slab etc.

Or somewhere behind the panel is either running back into the ground or links to that soil pipe i mentioned which would mean the water would require a bond right??

 

[spark 68]

Re: Plastic Water main with coper throughout.

Or somewhere behind the panel is either running back into the ground or links to that soil pipe i mentioned which would mean the water would require a bond right??

Pretty much , that is why I look for the very low reading consistent with the gas bond, or the 23k or above reading.

The whole idea is to keep everything inside at the same potential, which is why we bond as near to the incomer as practical.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

Right im telling the client on monday to get the bloke back to primarily get the soil pipe done as should have been from the get go and secondly advise the water which i will back up in my covering letter. Job done[emoji106]

 

[davesparks]

Re: Plastic Water main with coper throughout.

It's unusual for a soil pipe to need bonding as they aren't usually available to be touched within the installation. Unless it still has the original lead wastes etc.

 

[rattlehead85]

Re: Plastic Water main with coper throughout.

It's unusual for a soil pipe to need bonding as they aren't usually available to be touched within the installation. Unless it still has the original lead wastes etc.

Soil waste runs up through the bathroom cupboard slap bang next to a spur serving a low level tubular heater.

 

[Des 56]

Re: Plastic Water main with coper throughout.

Man installs wiring,issues certificate (which does not include water bond because its plastic incomer) tests confirm its not extraneous
He bonds the gas service because it requires to be so

Other man comes along and fits boiler (which now links the non extraneous water pipes to the extraneous gas supply pipe)

Eicr carried out and states the water pipe "needs bonding" because it does not satisfy the inconclusive tests carried out
The tests are inconclusive because the gas cannot be separated from the water

It seems to me the original installer has a reasonable argument that his actions were valid, argument can be made by him that unclear test procedure has made this an issue rather than the original installation

 

[Geordie Spark]

Re: Plastic Water main with coper throughout.

Man installs wiring,issues certificate (which does not include water bond because its plastic incomer) tests confirm its not extraneous
He bonds the gas service because it requires to be so

Other man comes along and fits boiler (which now links the non extraneous water pipes to the extraneous gas supply pipe)

Eicr carried out and states the water pipe "needs bonding" because it does not satisfy the inconclusive tests carried out
The tests are inconclusive because the gas cannot be separated from the water

It seems to me the original installer has a reasonable argument that his actions were valid, argument can be made by him that unclear test procedure has made this an issue rather than the original installation

That's it - in a nutshell! :hurray:

Now that you've cleared that up, can you clarify something that's been puzzling me all through this thread?

WHAT is this "coper" in the thread title?? :confused5:

 

[David Marshall]

Re: Plastic Water main with coper throughout.

Just put one in cover your back as water still conducts and you dont know how far the plastic main goes I'm obviously using my immagination here but at least it has a MPC anyway the water my be connected to a gas combi or something. I would not dwell on this issue just put one in

 

[davesparks]

Re: Plastic Water main with coper throughout.

Just put one in cover your back as water still conducts and you dont know how far the plastic main goes I'm obviously using my immagination here but at least it has a MPC anyway the water my be connected to a gas combi or something. I would not dwell on this issue just put one in

Water alone is non-conductive, impure water such as that which is supplied by the public water mains has limited conductivity.
As far as I know the volume of water in a 600mm length of 22mm plastic pipe has sufficient resistance as to be considered an insulator at 250V

 

[spark 68]

Re: Plastic Water main with coper throughout.

Just put one in cover your back as water still conducts and you dont know how far the plastic main goes I'm obviously using my immagination here but at least it has a MPC anyway the water my be connected to a gas combi or something. I would not dwell on this issue just put one in

No you shouldn't "just bond" without testing and a proper assessment, you may introduce a hazard where none previously existed.

 

[Essex_]

Re: Plastic Water main with coper throughout.

If the results of your test on the water main have been affected by the main bond to the gas then you have not carried out the test correctly.

Isolate the installation, then disconnect the earthing conductor from the MET (or remove test link). You then test between the incoming earth and the suspected extraneous part.

I'm not surprised you have been accused of trying to get work by unscrupulous means, a plastic water main which feeds surface clipped installation pipework is unlikely to be extraneous.

That was really good advice until the last paragraph. No need for that and ruined the thread IMO.

 

[Geordie Spark]

Re: Plastic Water main with coper throughout.

Water alone is non-conductive, impure water such as that which is supplied by the public water mains has limited conductivity.
As far as I know the volume of water in a 600mm length of 22mm plastic pipe has sufficient resistance as to be considered an insulator at 250V

Finally somebody has grasped it!!

 

[GB.Kayak]

Re: Plastic Water main with coper throughout.

Was called to a job yesterday where a company had completed an EICR on a house fed via a plastic water main with internal plumbing done completely in copper. They had put a c2 observation code for a lack of main protective bonding to the water. The customer had shown me the EIC cert she had been given by the original company who had completed a rewire on her property.
Disconnecting the earthing conductor at the intake position and completing an IR test to the internal stopcock on the water gave me a reading of 0 megohms. To me this has indicated that somewhere within this installation the copper pipework is earthy and deemed extraneous and does warrant a main bond. I did think this could be gaining a reading through the boiler gas connection (which is bonded) I am leaning on the side of advising the client to get the original contractor back to sort this. Opinions on this before doing so would be appreciated.

Why are you carrying out an IR test when you should be measuring the continuity or otherwise of the various components in the system? Surely IR testing serves one purpose only; a proof test of the insulation in a circuit?

 

[Leesparkykent]

Re: Plastic Water main with coper throughout.

Why are you carrying out an IR test when you should be measuring the continuity or otherwise of the various components in the system? Surely IR testing serves one purpose only; a proof test of the insulation in a circuit?

https://m.youtube.com/watch?v=v38PfIVy2rI

watch this it'll explain it.

 

[GB.Kayak]

Re: Plastic Water main with coper throughout.

https://m.youtube.com/watch?v=v38PfIVy2rI

watch this it'll explain it.

L, thanks for the hint ... I also took a look at the manual for my multifunction tester ... Doh!