sup bonding,bonding and earthing

[esc]

Hi guys. With reference to 131.8. and maintenance.
As i see it from posts on here, a like for like is different to an addition or alteration?
Just as an example, there's been a number of posts on here regarding replacing a like for like shower and all seem to agree it's not notifiable, me included, thats straight forward.
131.8 refers to ensuring that earthing and bonding are adequate for an addition or alteration.
When doing a like for like, where do you stand on the issue of bonding, given that 131.8 "sugests" this is only required to be adequate when doing additions or alterations, which like for like isn't? No extra load no relocation of cables. Effectivly no changes to the installation.

If you went to Mrs smiths and she needed a socket front replacing because there was a crack in it and she had no bonding to her services, what should you do? What do you guys who have fitted a replacment shower do? Is there somwhere in the brb that refers to like for like as such in relation to the existing bonding arangments?
Cheers

 

[malcolmsanford]

I would say as far as the Regs are concerned "like for like" is deemed "maintenance" and there is very little in the regs concerning this other than 132.12 and 513.

As far as your bonding scenario is concerned I think like everything in our industry you have to assess each situation as you find it. If there was a broken face plate to a socket and no main bonding, would you be leaving the installation in a dangerous condition if you didn't replace that face plate? Chances are yes and you would replace it.

If you were asked to fit a a like for like replacement for a shower and there was no RCD protection or main/supplementary bonding then you have IMO don't have much options. IMO the manufacture of that shower would 99/100 insist on RCD protection and so that takes care of that. As the shower is classed as being installed in a special location I would not fit it unless the bonding was brought up to scratch If ​there were extraneous conductive parts within the room.

 

[esc]

Hi malcomsandford, thanks for your reply, yes, absolutley change the face plate and i appreciate the importance of bonding. I appreciate my responsibilities to ensure her safety regarding the crack in the SO, and i can't insist she has her bonding brought up to date before fixing the SO as there is an imediate danger. Maybe the senario wasn't that good, just like the shower example, that being a special location, as you say options are limited.
Suppose what im trying to ask is: excluding imediate safety issues as such an special locations, if she just wanted her plastic faceplate swapping for a shiny metal one on a like for like basis, what do you do regarding non existing bonding. And if its the case you must bond, how far do you go beyond main bonding. Do i go around the whole house checking every circuit and extraneous part, supplymentary bonding?
Cheers.

 

[malcolmsanford]

Use your regs like you would any other tool and use it for what is best. Look at the introduction of the regs page 4 of the BRB

"Existing installations that have been installed in accordance to earlier editions of the regulations may not comply with this edition in every aspect. This does not mean that they are unsafe for continued use or need upgrading"

So we know for an alteration or addition in the installation we need to upgrade our bonding and earthing but changing a class II socket face plate to a Chrome Class I is not IMO an alteration or addition to the installation. I would though be making sure that reg 412.2.3.2 was adhered to.

Of course you have a care of duty to inform the customer of bonding, RCD protection etc etc, but to insist on it or not do the work is perhaps a little stringent

 

[esc]

Thanks for your insight malcolmsanford. At my regs a lot along with the OSG, just cross referencing information in there can get confusing and at times sound contradictory to something you read earlier, leading to confusion.
Thanks for the paragraph from the introduction. With the keyword being: "unsafe", and quite right. If pre 17th installations show themselves to be unsafe, then bring it up to date, but if its safe as a pre 17th, then the only reason i can see to upgrade to the 17th would be to make it safer than it currently is, an option that can be put to the customer as you say
Cheers

 

[Deleted member 26818]

Regulation 131.8 doesn't state: "that earthing and bonding are adequate for an addition or alteration".
That was the wording used in the 16th Regulation 130-07-01.
What 131.8 states is: "Furthermore, the earthing & bonding arrangements, ifnecessary for the protective measure applied for the safety of the addition or alteration, shall be adequate."
As such, you first have to determine whether bonding is necessary.
Protective equipotential bonding would not be required for ADS or the operation of an RCD, although it is a protective measure required for special locations, if supplementary equipotential bonding is to be ommited.
Supplementary equipotential bonding, is required in special locations, unless the requirements of Regulation 701.415.4.5 (iv), (v) and (vi) have been met.
It is also a method used to reduce Zs on circuits where the measured Zs are too high for ADS to be achieved in the required times.
If bonding is not required for the protective measure applied for the safety of the addition or alteration, then there is no requirement for you to ensure it is adequate.

 

[esc]

Thanks spin. I stand corrected on how i interpreted 131.8, obviously i dont know what its saying and the more i read it the worse it gets. Its worded awkwardly, or im daft. Reading what you say:
I get that under normal cicumstances its not required for ADS, unless we have too high a Zs and can find use for it there, (although i would be sceptical about why there's a high Zs in the first place) or for RCD operation. I understand its use in special locations where 701.415.4.5 (iv), (v) and (vi) cant be met. I understand it's use generally to minimise PD's between exposed conductive parts and extraneous conductive parts under a fault.
I'm currently reading what you say in your last sentace as: for an addition, alteration, or like for like replacement that is done, provided that the earthing arrangement gives adequate protection in conjunction with the circuits PD, for the safety of the add/alt, like for like, there is no need to consider bonding with respect to that circuit? Am off target im sure!?
I was just wondering where we stand on the broader matter, of, when doing a like for like in a house with no bonding to services and not in a special location, whats the concensus is, assuming the circuit test out ok.
Thanks

 

[grimysparks80]

For me, if you`re not doing an addition or alteration then as long as youve informed the customer that the bonding should ideally be brought up to date then you have covered yourself.

Ive found that on occasion when replacing boiler controls the customer will refuse to have the bonding done, as they dont want floors up and earth cables run in just for a new timer or room stat.

I always inform them that their current installation is not up to current regs and get them to sign something to confirm that they have been informed.

 

[davie spark]

The earthing/bonding advice in the OSG is that you earth/bond from the shower earth terminal to other earthing points in the bathroom, i.e. looped cpc round the room (difficult I know). If I was you I would complete a minor works cert and on it point out that main bonding is missing AND notify the client re getting 'extra' work to install it. If I was employed by a company and not self employed I would also report the lack of bonding to my employer. Cover your own back.