Can i add new circuits onto installation with undersized main bonding?

[claret73]

Section 2: 2.1 & 2.2 Part P Document...

 

[Deleted member 26818]

Regulation 311.8
"No addition or alteration, temporary or permanent, shall be made to an existing installation, unless it has been ascertained that the rating and the condition of any existing equipment, including that of thedistributor, will be adequate for the altered circumstances. Furthermore, the earthing & bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate."
Is main protective bonding required for either ADS, or for an RCD to operate?
Supplementary bonding may be required for ADS, if circuit Zs are too high.
As such, if the protective measure you are intending to ues, does not require bonding to operate, there is no requirement to upgrade the bonding.

 

[telectrix]

IMO, you need to ensure that the bonding is adequate. you don't have to bring it up to current regs. it would be a code 4 on a PIR.

 

[Deleted member 9648]

Yes where PME conditions apply, both the earthing conductor and the protective bonding conductors have to be a minimum of 10mm².
However, bonding is not required for ADS or for RCDs to operate, as such there is no requirement to upgrade the bonding.

You've lost me there spin.....the main bonding has nothing to do with ADS or RCD's...or am I missing something?..(been a long day).
Minimum 10mm is required on TNCS systems because the bond in theory may carry a significant load current under certain conditions...as long as the existing 6mm shows no signs of thermal damage it is reasonable to assume it is adequate, and there is no need to upgrade for a minor works which will not significantly change the characteristics of the installation. It would be good practice to upgrade,but in the end it is your call....you are the competant person.

 

[Deleted member 26818]

You've lost me there spin.....the main bonding has nothing to do with ADS or RCD's...or am I missing something?..(been a long day).
Minimum 10mm is required on TNCS systems because the bond in theory may carry a significant load current under certain conditions...as long as the existing 6mm shows no signs of thermal damage it is reasonable to assume it is adequate, and there is no need to upgrade for a minor works which will not significantly change the characteristics of the installation. It would be good practice to upgrade,but in the end it is your call....you are the competant person.

My point exactly wirepuller.

 

[Deleted member 9648]

Regulation 311.8
"No addition or alteration, temporary or permanent, shall be made to an existing installation, unless it has been ascertained that the rating and the condition of any existing equipment, including that of thedistributor, will be adequate for the altered circumstances. Furthermore, the earthing & bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate."
Is main protective bonding required for either ADS, or for an RCD to operate?
Supplementary bonding may be required for ADS, if circuit Zs are too high.
As such, if the protective measure you are intending to ues, does not require bonding to operate, there is no requirement to upgrade the bonding.

Spin...main bonding is necessary for virtully any alteration or addition to an installation as there are likely to be conductive parts.....and it will be necessary to ensure there can be no potential difference between conductive parts of the addition and existing extraneous conductive parts......An RCD and ADS does not change that.

 

[topquark]

You've lost me there spin.....the main bonding has nothing to do with ADS or RCD's...or am I missing something?..(been a long day).
Minimum 10mm is required on TNCS systems because the bond in theory may carry a significant load current under certain conditions...as long as the existing 6mm shows no signs of thermal damage it is reasonable to assume it is adequate, and there is no need to upgrade for a minor works which will not significantly change the characteristics of the installation. It would be good practice to upgrade,but in the end it is your call....you are the competant person.

That's exactly what Spin is saying wirepuller

 

[Deleted member 9648]

Like I said......been a long day:cyclist:

 

[claret73]

I get the replies guys from a Practicable view. IE: Do a Continuity check on the 6mm...Great! Visual check, Great! but without sounding a Jobsworth, the Regs don't do Practical Viewpoints. Only Black & White...& if this is interpretable for me I'd upgrade as then I've conformed...A PIR wasn't mentioned, only additional installations to current Regs...of which might be an EIC?...I think this'll be whatever each op is happy with...

 

[Deleted member 9648]

I get the replies guys from a Practicable view. IE: Do a Continuity check on the 6mm...Great! Visual check, Great! but without sounding a Jobsworth, the Regs don't do Practical Viewpoints. Only Black & White...& if this is interpretable for me I'd upgrade as then I've conformed...A PIR wasn't mentioned, only additional installations to current Regs...of which might be an EIC?...I think this'll be whatever each op is happy with...

Well they are not entirely black and white...not statutory.....I think it is reasonable to assume that if the install is not going to be significantly altered,and has survived for several decades on the 6.0mm bonds...there is hardly likely to be any problems. After all,what is likely to happen if you dont upgrade?...it's still bonded.

 

[Deleted member 26818]

Wire puller, in the 16th, we had EEBADS.
In the 17th we have ADS.

In the 16th we had this Regulation:
130-07-01
No addition or alteration, temporary or permanent, shall be made to an existing installation, unless it has beenascertained that the rating and the condition of any existing equipment, including that of the distributor, which will have to carry any additional load is adequate for the altered circumstances and the earthing and bonding arrangements are also adequate.
In the 17th we have this Regulation:
131.8
No addition or alteration, temporary or permanent, shall be made to an existing installation, unless it has beenascertained that the rating and the condition of any existing equipment, including that of the distributor, will be adequate for the altered circumstances. Furthermore, the earthing and bonding arrangements, if necessary for the protective measure applied for the safety of the addition or alteration, shall be adequate.
Notice the change in the wording?
All I can assume, is that because EEBADS is no longer considered a protective measure, we now no longer have to even check that the bonding is adequate.

 

[Deleted member 9648]

Hmmmmm......going to look at the BGB later.

 

[ezzzekiel]

if its an existing installation and main bonding shows no signs of deterioration and has a resistence low enough then it can be left in situ as its proved adequate, write it up on the test sheet.

 

[goldie]

Thanks for the input guys, Spoke to my governing body today (nic eic). Was basically told to use my discretion based on different factors of the existing installation i.e main protective bond condition and also based on the type of work i shall be carrying out,
just as many of you guys have mentioned. Its hard sometimes knowing where to draw the line and look like your not trying to do work and charge for it when not necessary, but at the same time not cut corners and avoid doing work that should be carried out according to bs7671.