Main bonding, following on from other threads

[ADS]

So you mean a sparky goes to a house and adds a socket, does it properly and they are now responsible for the whole of the old installation ?

Nooooo.........The bloke who wrote the article was describing why you would be responsible for the circuit that you were adding to/altering - it was a good read and made sense - but obviously some don't agree......they want to just be responsible for their little 'spur' that they added.

 

[Sidewinder]

ADS,

Taking your comment further, and relating it to my scenario, the thing is the circuit is only a code 4 at the moment if you were to PIR it.

Upstairs sockets, PME supply, mcb & cable co-ordinated, don't know the cable run feeding the socket outlets, so code 4 on a PIR.

Almost certainly complied on install, as long as it was correctly installed.

Would you want to pay for a PIR on the whole property considering it is not yours just to add 3 accessories, all protected by a 13A RCD fused connection unit?

Would you want to pay for the whole circuit to be upgraded in a property that is not yours and may well only be installed for a few months when there is no added value to the "bit" that you are paying for?

Would you want to pay for works being undertaken in your home that you were not paying for nor arranging?

 

[ADS]

ADS,You suggest ditching the 100mA, I asked for what, i could not see a reply mate any suggestions?

Post number 18:

To comply - an earth fault on the extended circuit would cut power to the whole installation.As the circuit that you are extending is fed via this 100 mA RCD, it should comply with current regulations.

And post number 21 (which you replied to):

Assuming the job is not in Scotland,Approved Document P, Section 2, 2.1

Where any electrical installation work is classified as an extension, the addition & alteration work must include:

a) such works on the existing fixed electrical installation in the building as are necessary to enable.....

the addition/alteration (the extension) ;

the circuits which feed it;

the protective measures &

the relevant earthing and bonding systems..........

....to meet the requirements

AND....

B) Establishing that the mains supply equipment is suitable.

So all four items listed above have to meet the requirements of the current regs........the 100 mA up-front RCD doesn't, and neither will a RCD fused spur......what about RCD protection for the rest of the circuit?

It says that the circuit/s feeding the addition have to meet the requirements - unless the 100mA is necessary for earth fault protection (e.g. TT), then it won't comply with the 17th as it covers the whole install.

---------- Post Auto-Merged at 20:42 ---------- Previous post was made at 20:39 ----------

ADS,Taking your comment further, and relating it to my scenario, the thing is the circuit is only a code 4 at the moment if you were to PIR it.

Upstairs sockets, PME supply, mcb & cable co-ordinated, don't know the cable run feeding the socket outlets, so code 4 on a PIR.

Almost certainly complied on install, as long as it was correctly installed.

Would you want to pay for a PIR on the whole property considering it is not yours just to add 3 accessories, all protected by a 13A RCD fused connection unit?

Would you want to pay for the whole circuit to be upgraded in a property that is not yours and may well only be installed for a few months when there is no added value to the "bit" that you are paying for?

Would you want to pay for works being undertaken in your home that you were not paying for nor arranging?

I'm not sure which of my comments your taking exception too.

 

[Sidewinder]

I'm not sure which of my comments your taking exception too.

I'm NOT taking exception, I am trying to draw out the debate!

---------- Post Auto-Merged at 20:46 ---------- Previous post was made at 20:43 ----------

I'm not handing this out on a plate you know I am trying to get people thinking!

There is more to some jobs than meets the eye.

---------- Post Auto-Merged at 20:47 ---------- Previous post was made at 20:46 ----------

Post number 18:

You did not say what to ditch the 100mA up front for here mate sorry, you just said add a 30mA FCU, you did not suggest a replacement for the up front 100.

There would also be no discrimination between the two thus that would be non compliant too...

---------- Post Auto-Merged at 20:48 ---------- Previous post was made at 20:47 ----------

Sorry, can't see what Post 21 provides as a suitable alternative to the 100mA up front which was the question I asked.

 

[ADS]

I'm NOT taking exception, I am trying to draw out the debate!---------- Post Auto-Merged at 20:46 ---------- Previous post was made at 20:43 ----------

I'm not handing this out on a plate you know I am trying to get people thinking!

There is more to some jobs than meets the eye.

I'm surprised you're not getting more input - it's a pretty important subject that would affect anyone doing domestics - but no-one seems to have an opinion - strange.

Let's face it, my opinions are only my interpretation of Part P, not how it is.

---------- Post Auto-Merged at 20:50 ---------- Previous post was made at 20:49 ----------

Sorry, can't see what Post 21 provides as a suitable alternative to the 100mA up front which was the question I asked.

You haven't told us why it needs an alternative.

What purpose is it serving?

 

[Sidewinder]

Quite ADS, I do quite a lot of these small mods and I have a formula almost.

It is a complex commercial situation, though not that much a complex electrical one.

I thought it may be a good way of trying to get some debate going without the OP being a question asking for help!

I am obviously open to suggestions and I am working with my client all the time on cost management vs total & absolute compliance.

Thing is as you know no two properties are the same!

They also are across all 3 supply types and spread across almost a third of Wales!

---------- Post Auto-Merged at 20:54 ---------- Previous post was made at 20:53 ----------

You haven't told us why it needs an alternative.

What purpose is it serving?

IIRC it was you who suggested ditching it, I never said it needed removal!

 

[ADS]

It is a complex commercial situation, though not that much a complex electrical one.

You're confusing me now - the OP said it was domestic.

IIRC it was you who suggested ditching it, I never said it needed removal!

That's what I mean - if it's not serving the purpose that you would normally fit a 100mA RCD up-front for (i.e. earth fault protection on a high Ze), then it should be removed to prevent a fault on one of the circuits (e.g. the one you are extending), taking out the whole installation.

 

[Sidewinder]

It is a domestic install, by commercial I meant in the business sense it is a complex business situation.

My client is commercial by the way.

Right I see now, so you feel that I should remove the 100mA up front. OK.

This is an old Wylex rewirable board with this rcd as the main switch, and plug in 3871's.

I can't remove the complete up front rcd and fit a main switch as this would reduce the safety of the install would it not, also there may be an electric shower, can't remember the plumbing side is in the loft so I only spent a few minutes looking under the toilet!

Plus the room I am working in is not a "special location", I am not introducing any additional earthy items.

Keep going, I'm not decrying your point, you just don't see the full picture and that is partly my fault, but if I did reveal it then many would cop out.

 

[ADS]

Will you not have a 'discrimination' problem yourself - you did say you're installing a 30mA fused spur to feed your added sockets?

 

[Sidewinder]

Yes,

There will be a discrimination problem, by design, don't forget the 30mA rcd fcu is feeding 2 downstream 30mA rcd protected socket outlets

 

[ADS]

Yes,There will be a discrimination problem, by design, don't forget the 30mA rcd fcu is feeding 2 downstream 30mA rcd protected socket outlets

So why RCD protected socket outlets?

 

[Sidewinder]

Connected equipment spec.

Also redundant protection.

 

[Sidewinder]

X( :x ROTFWL

 

[davetheglitz]

My take:-

Bond in 10mm to boiler. Effectively cross bonds gas and water via metal manifold. Note location and method on MWC and on CU

Earth - check via adiabatic - often adequate already, If not - upgrade.

Add 30mA RCD SFS for new sockets - limitation wrt discrimination - but very minor in the scheme of things.

Existing installation not degraded

New installation safe

All bonding in place where convenient and documented.

Job done!

 

[steptoe]

My take:-Bond in 10mm to boiler. Effectively cross bonds gas and water via metal manifold. Note location and method on MWC and on CU

Earth - check via adiabatic - often adequate already, If not - upgrade.

Add 30mA RCD SFS for new sockets - limitation wrt discrimination - but very minor in the scheme of things.

Existing installation not degraded

New installation safe

All bonding in place where convenient and documented.

Job done!

nice to see you back Dave,

 

[davetheglitz]

Thanks Steps! Two weeks holiday on canal barge - then 2 weeks work - so feel like I need another holiday!

 

[Sidewinder]

DTG,

Thanks for taking a pop mate.

BTW the PO turned up from the customer today.

Job due 3rd Wk July.

Not sure about the 10mm bonds, will probably upgrade the gas, cross bonds to 16mm and install a 16mm main water bond to ensure compliance & not with 7671!

Even though at this stage, the client & I are not sure of the "other" regs apply!

I do agree with the bulk of your post though, i.e. existing not degraded or made unsafe or less safe.

Redundant protection is more significant in this case and would blow the discrimination requirement in 7671 "out of the water" as it were.

Thanks peeps for keeping it polite & clean, we can go on as much as we like.

My NIC inspection is before this job, but as it is so close to my home if you want next year I'll take my inspector there and see what he thinks of my solution if we don't "sort" it here first.

There will be a member or 2 who are party to additional info though.

Sorry peeps.

 

[Manator]

I have been having the same debate, one way I look at it is if a claim was ever made against them (you know who), would they then pass the buck, because it was not installed as per their own regulations?

Better safe than sorry I say, even if it is only for one person.

 

[Sidewinder]

I know mate, difficult depends though on IF they can prove their regulations apply to a private domestic premise!

I have copies of "all" of the relevant memorandums on the way I was promised them yesterday.

 

[Manator]

Did you not get the copy I sent you?