upgrade of bonding

[beaver74]

now can any one tell my if when a board is changed on a tn/c/s system if the main bonding is 6.00mm this can be left
i am of the opinion that it must be upgraded but i am coming across more and more NIC completed boards where the the bonding is left as 6.00mm
i am aware that on a tn/s system the 6.00mm will do but with p.m.e a lost neutral the earth can be carrying full current which is why 10.00mm is requiered

have looked at a job today that need additional circuit so will need bonding upgraded to comply but the council have just had the board change and givern certs and now im saying bonding should be upgraded can see me getting stuck in betweenthe to of them
so any definant answers out there please

 

[acat]

I think page 28 of OSG is the answer your looking for if you get stuck in the middle PME supply main protective bonding is shown as 10mm minimum.



Chris

 

[Des 56]

Alterations and Additions in Domestic and Similar Premises
Click on the link and go to edq12
Here is the safety council answer
It seems not so

 

[Guest123]

Alterations and Additions in Domestic and Similar Premises

Talk about vague......"not necessarily"......."may not"........maybe.....perhaps.....

What a load of trash!!!!

I cant believe that they would state that on their website!!!

Ok there may not be any signs of thermal damage to date but.....what if a fault occured the day after the CU was replaced and something seriously bad happened due to the 6mm bonding being left unchanged, the first thing any lawyer would quote would be that the bonding conductors were of an insufficient size and your swede would be on the block with no-where to go.


I dont think saying that it was on a website somewhere would cut it I'm afraid.


Indeed 544.1.1 and table 54.8 blows the statement made by the ESC totally out of the water!!!!

I despair, I really do.

If our so called governing bodies cant get it right what hope do the rest of us have!!!



Rant over

Apologies.

 

[guitargraham]

Hi

Lenny wrote "Indeed 544.1.1 and table 54.8 blows the statement made by the ESC totally out of the water!!!!

Through my training they refer to the BIG RED BOOK as the BIBLE???

In the eyes of the LAW thats what they would refer to, not what this site or that site said.

Cover your ---

Graham

 

[sparks1234]

This is one of the things that is mad about this country, you can be improving protection by replaceing an older board to a newer one with RCD MCB etc etc but because the earth is ONLY 6mm where it should be 10 sparkies have to walk away if the client cant have the earth uprated for whatever reason.
I am not saying its right or wrong that the earth should be 10mm not 6 but we are so tied up in regulations now it drives you mad, surely a small improvement is better than none

 

[Eggster71]

As stated above, the regs book states minimum 10mm for a PME supply. If the 6mm has been left than as far as I'm aware then this should be noted as a departure from the regulations on the cert with calculations etc to confirm compliance. It's possible the cable will be adequate if calculated but if my NICEIC inspector saw that he'd go ape and I'd expect him to insist on an expensive re-visit once I'd pulled in the 10mm cable!

 

[Des 56]

Quotes

if my NICEIC inspector saw that he'd go ape and I'd expect him to insist on an expensive re-visit once I'd pulled in the 10mm cable!

I dont think saying that it was on a website somewhere would cut it I'm afraid.

Being of the same opinion as yourseves,the bonding should be 10mm or not
A simple yes or no,safe or unstable/unsafe.no half measures,but the various people we supposed to listen to cannot or will not make things straightforward

As to the quotes
No 1
Remember the safety council in all but name are the NICEIC, so to say he would go ape about advise off his own employer is "stretching" the reaction I'm sure

No 2
The web site is not an "any old information set of people"
They are a government recognised organisation, set up supposedly for consumer safety advise, and do hold a lot of clout,and any judge would take their advise as coming from a responsible organisation

Like the whole of our trade at the moment,it is just over organised chaos

 

[Scott F]

Right and wrong Good or Bad ?

Down to the individual at the end of the day.

I see where you, are coming from Lenny

However if the client doesn't want to pay and you have informed them of the situation and made a note on

the departures . Are you then going to walk ? Don't think I would .

Have had exactly same situation Scheme provider (to cover their own ---'s ) say no, BUT assessment officer

said as long as the above I would do it, and as work is thin on the ground i would be foolish to walk .

Others may not agree - fair enough and if you are rushed off your feet and can pick and choose also fair

enough. In my opinion by noting on the cert you have covered your self.

 

[Guest123]

Quote from NICEIC Guide To Inspection and Testing - 17th Ed.

Page 170.

Regarding PME supplies.

"Where the inspector finds, in an existing installationthat the main protective bonding conductors have a cross-sectional area of 6mm, rather than 10mm as required by BS 7671, the inspector may, having carefully considered all circumstances, conclude that the defficiency does not pose a serious risk to the users".

"However the deficiency must be recorded together with the reasons why the inspector has concluded that the deficiency does not pose a serious risk to the users and an appropriate reccomendation on the report/certificate".

"This dispensation IS NOT allowed on a new installation OR a rewire. Neither is it permissable to an installation served by a PME supply which was commenced or worked on by the supply authority on or after 1988. Even where a PME supply was commenced before this date careful consideration should be given to any decision to rely on existing main bonding with a CSA less than that required by table 54.8 of BS 7671. The reason being that the main bonding conductors may have to carry network circulating currents continuously or for long periods."


Make of that what you will gents. My take is, leave it in and if anything happens it's 100% your fault and you are not covered by anything or anyone, noted on a cert or not.

I for one will not leave a 6mm earth on a PME system, either upgrade or dont do it, it's just not worth the risk for a £300 CU upgrade job.

9 times out of 10 if you show the customer the relevant info thay will be happy to upgrade and happier that you have their safety in mind and not out for a fast buck.

 

[Scott F]

Quote from NICEIC Guide To Inspection and Testing - 17th Ed.


Just playing devils advocate here Lenny......

But I was under the impression it was the IET 's rules and regs we had to follow not NICEIC

 

[Guest123]

Just playing devils advocate here Lenny......

But I was under the impression it was the IET 's rules and regs we had to follow not NICEIC

Absolutely mate....BS 7671 is crystal, 10mm minimum for PME supplies, end of.

It's the scheming providers (NIC) that are clouding the issue as there is no mention of leaving a 6mm on PME's in ol'red anywhere at all.

544.1.1

Table 54.8

 

[Des 56]

Absolutely mate....BS 7671 is crystal, 10mm minimum for PME supplies, end of.

It's the scheming providers (NIC) that are clouding the issue as there is no mention of leaving a 6mm on PME's in ol'red anywhere at all.

544.1.1

Table 54.8

Spot on

Thats the reason we have chaos in the industry,the likes of the NIC giving advise to its members and dictates to the safety council for changes to the intended IEE safety advise that contradicts those IEE regs

They should stick to interpriting the IEE regs and not making up the NIC regs
They are a organisation that dips its toe in matters that should not be their remit
Advise and downright contradiction are different animals
They need a kick up the rectum from the IEE
In fact they need a lot of change,but thats enough for the mo for that most arrogant of organisations

 

[Guest123]

Agreed Des.

NIC seem to be getting a bit to big for their boots. As you rightly say IET compile and publish the wiring regs not NIC or ECA or anyone else.

In a court of law although it is a non-statutory document BS 7671 is what will be referred to not NIC's or anyone elses rules.

I'm afraid the issue we all face is having to be members of one of these schemes that seem to please themselves on every aspect of their existance.

 

[sparks1234]

Called the ECA today on this and their take was, no its not right but if you cannot get a 10mm to the pipe then an inspection should be carried out to check for signs of heating up etc etc and then if that is OK, you can change the consumer unit but make a note on the certificate