Cu Change

[Sidewinder]

PD,

If correctly tested, when checking main equipotential bonds, then there can never be parallel paths.

Thus if the test was done correctly then Nicky is correct, however, if the test was not done correctly then you could well be correct.

I don't know how the test was done...

 

[OnOff]

for what purpose..........it doesn't need another one.

What I was getting at is if you can't access the point where the cable connects to the gas water..........it might test OK now but might be subject to some external influence that could affect the integrity of the connection BEFORE the next periodic etc. Water, chemical leak etc under the floor. Playing devil's advocate I know but I just wondered if it would be "belt and braces" to run another cable in bonded to where IS accessible. Then if you have TWO main equipotential bonding cables should that be at least noted?

 

[SPECIAL LOCATION]

I put a deviation on my installation cert today " Bonding connection to the gas supply pipe is not accessible"

The bond is there, in the wall. I did a continuity test and got very good results so i strongly believe the connection to be there.

I am not going to make a big hole in the tenants tiled bathroom wall to locate it. It is nothing to do with if i can be ar**ed or not.

It is simply not practicable

So you disconnected the gas pipe from the boiler and then tested it did you?

Otherwise, the "good results" you got could well be the gas pipe just connecting to earth via the boiler casing and boiler earth.

Assuming a scenario where you have two separate bonding conductors at your CU,

one has been proven to be to the water pipe and the other you suspect is going to the gas pipe.....

if both bonding conductors are disconnected at the CU they should theoretically be just single lengths of copper wire...

One attached to a water pipe one attached to a gas pipe and neither directly connected to electrical earth...

As we know the resistance of the copper wire,

and we could approximate the length of cable by the size of the property...

say 15m of 10mm (0.03ohms)

So if you use a long lead from your isolated bonding conductor to an accessible part of the pipework

and you get your expected resistance +/- 0.05ohms..

then I would tend to agree with Nickys proposition that the bond is intact somewhere..

but NOT accessible!

opcorn

 

[Nicky Tesla]

yes thats exactly how i did it spesh

 

[Sidewinder]

That is the ONLY way to do it "really"!

 

[OnOff]

I wasn't going to post this up but in light of the recent comments ref lack of posts generally thought I would. I'd have left it before, not pushed the issue if I felt I hadn't got an answer and carried on wondering. Everyone above has said if it tests ok but you can't see it then leave it. In my case it tests OK but I'd rather add a second main equipotential bond to gas and water so there is a visible "bond" in an accessible place. IS THAT AN ISSUE, GOING BELT AND BRACES? 

One of the reasons I bring it up again is I've just had, today, British Gas in doing the boiler and he noted that main equipotential bonding wasn't visible within 600mm of the gas and water. He commented it's probably buried under the floor and the phrase he actually used was "supplementary" bonding not being visible so I explained that testing with a long lead suggests it's all good. I'm just thinking what's the harm in doubling up so as to avoid comments like that again. Cheers.

 

[kme]

There wouldn`t be any harm in fitting a second one, which was accessible. I suppose its akin to installing new bonds; say 10mm for a domestic, when the existing are 6mm. I don`t make a point of disconnecting the 6mm bonds, just because I`ve put 10mm in - there`s no need.

So, your "belt & braces" approach IS valid - and, if the customer will pay for it, why not? You`ve made the installation more compliant, by installing within 600mm / accessible; so its all good.....plus you`ve generated extra income

 

[OnOff]

There wouldn`t be any harm in fitting a second one, which was accessible. I suppose its akin to installing new bonds; say 10mm for a domestic, when the existing are 6mm. I don`t make a point of disconnecting the 6mm bonds, just because I`ve put 10mm in - there`s no need.

So, your "belt & braces" approach IS valid - and, if the customer will pay for it, why not? You`ve made the installation more compliant, by installing within 600mm / accessible; so its all good.....plus you`ve generated extra income

Cheers for that. I didn't actually see the BG guy but left a note on the door of the airing cupboard including the sentence ".........boiler fed from 15A fuse in cu.............". Basically it's the old radial feeding the airing cupboard. Seems there was some confusion over this with the BG guy not knowing. I got my missus to go over and let him into the house. Apparently the conversation went like this

BG: Wht does "cu" mean?

Missus: Could it be "Cupboard Under stairs? 

BG: Nah, that's where the fuse board is.................Hang on, he means CONSUMER UNIT!"

:lol:

From now on CU has a new meaning!

 

[Guest]

PHEW! Shouldn't this be a 'simple' case of, fit an up to date CU, therefore assume RESPONSIBILITY for the installation it serves as a whole,therefore, bonding/earthing should be brought up to date also.

I's dotted,T's crossed,means i will sleep at night.

 

[ProDave]

....

BG: Wht does "cu" mean?

Missus: Could it be "Cupboard Under stairs? 

BG: Nah, that's where the fuse board is.................Hang on, he means CONSUMER UNIT!"

:lol:

From now on CU has a new meaning!

How about for those used to old fashioned Fuse boxes:

Consumer Unit New Technology :coat

(too much wine tonight)

 

[apprentice87]

Hi JTI Sparks,

If you took your car to a garage for an MOT and they passed it but wrote on the cert "When you take "car needs 4 new tyres as they are below the limit" do you think this would be acceptable???

Fact of the matter is; when you are in business, once you have quoted, you have quoted, end of. If you then find you miss-quoted and make a loss, then that is part of business life, along with bad debt.

You win some, you lose some. Just take the knock, do the bonding, keep the punter happy, and that way you might pick up a LOT more work. Upset the punter and you can guarantee that he will tell every one he knows how "terrible" [the punters words, not mine] you were.

Just imagine if he got one of them telly programs, [round here they do one called the ferret] that would come along and do a half hour slot on you with loads of experts telling the world how dangerous it was and how you could have killed loads of people, and maybe caused the end of the world too.. How long do you think you would have a business then...????

With a business, comes ups, and downs, but most of all RESPONSIBILITY..

Finally, before you do any more quotes/installs, just remember that one day you may be called upon to give evidence in a coroners court...

Not having a go here, but this is just the way it is....

john..