Plastic Water main with copper throughout.

[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.