mcb / rcbo

[JohnW2]

.... is it logical to consider that you must notify the change of CU but not if you change every "active" component within in it and potentially alter the characteristics of the protective devices?

In a word, no (i.e. it is not logical) - but are LABCs allowed to make up their own rules and require something which is specifically excluded by the legislation?

Kind Regards, John

 

[Paul_C]

Yes five LABC's in my area say that this is notifiable on the basis that the characteristics of the circuit have been fundamentally changed

Where does the exemption in schedule 4 for replacing equipment stipulate that's it only on the condition that circuit characteristics are unchanged?

There are specific references in some clauses to "where the circuit protective measures are unaffected," but 1(a) is not among them.

is it logical to consider that you must notify the change of CU but not if you change every "active" component within in it and potentially alter the characteristics of the protective devices?

It may not be logical, but there are many instances in schedule 4 of notifiable vs. non-notifiable jobs in which logic seems to have played very little part.

 

[Paul_C]

EDIT, just reading my notes from that meeting. They (LABC) would consider that the system (consumer unit) as a whole would have been fundamentally altered and would consider that the related circuit characteristics would have been altered.

Still the same question: Where does the exemption in 1(a) stipulate that the replacement is notifiable on those grounds?

Reasonable though that might be (in common sense terms) what part of Schedule 2B do they think allows them to require notification on the grounds that the characteristics of the circuit have been changed?

John,

Under the new 2010 version of the Building Regulations which came into force a few months ago the notification exemptions are now contained within schedule 4:

http://www.legislation.gov.uk/uksi/2010/2214/schedule/4/made

Not that it changes the points both you and I are making.

...and, in passing, I've often wondered ... what on earth is 1(h) doing there??

The new schedule 4 groups together all exemptions from notification for the entire set of building regulations, not just Part P. Clauses 1(j) through 1(m) also relate to non-electrical items.

 

[sparkticus]

It costs £2.50 to notify - hardly going to damage the bank.

Exactly and I always notify. However, this brings up a grey area as far as I can see. Though the regs are full of grey areas, this one is wide open for interpretation. In my view it is wise to practice common sense and common sense tells me that if you have to notify to change a CU then you have to notify if you change virtually everything of any consequence in it otherwise we are talking about notifying to change a chunk of plastic and a few bus bars and as you say there is potential to alter a circuit serving a special location/bath/shower etc by changing an MCB to an RCBO.

I can say that the two LABCs I mention fully expect notification for anything that alters the characteristics of the CU and/or the final circuits.

 

[Paul_C]

If you change one mcb for rcbo and it is not notifiable - you could end up changing them all - at what point would it become notifiable?

When it becomes work which is not specifically exempted by schedule 4.

Also we are not told by the OP which circuit is affected. If it in a special location, kitchen etc then it would become notifiable.

The condition of not being in a kitchen or special location applies to adding new sockets, lights, etc. Replacement of equipment is exempt from notification no matter where it's located.

It costs £2.50 to notify

It will cost a whole lot more than that if you're not registered under one of the appropriate schemes.

 

[Paul_C]

but are LABCs allowed to make up their own rules and require something which is specifically excluded by the legislation?

No, but they often seem to think they are!

 

[sparkticus]

You see, I am struggling with this:

C) re-fixing or replacing enclosures of existing installation components, where the circuit protective measures are unaffected;

To me, despite that it relates to "enclosures" by implication it suggests that any change of protective devices that are not literally one for one in performance and capability is notifiable.



How does anything below specifically exclude circuit protective devices?

1. Work consisting of—
(a) replacing any fixed electrical equipment which does not include the provision of—
(i) any new fixed cabling, or
(ii) a consumer unit;

What am I missing (and I may well be missing something)?

Is an MCB fixed electrical equipment?
or is it a circuit protective device?
or is it both?



For my sake (because I may be misinterpreting something) can we go back to basics:

1) is changing a whole consumer unit notifiable?

2) if 1) is notifiable then what is the definition of changing a consumer unit?

3) what is the difference between changing a consumer unit and changing the essential characteristics of a consumer unit?

4) would anyone regard changing an MCB for an RCBO on any circuit as altering the characteristics of that circuit?

5) would anyone regard changing an MCB for an RCBO as re-designing the related final circuit?

 

[ricicle]

Where's Ban when you need him ?

 

[dormermike]

[quote="Paul_C";]

It costs £2.50 to notify

It will cost a whole lot more than that if you're not registered under one of the appropriate schemes.[/quote]

That was my understanding too, that it costs a couple of hundred if not registered on one of the schemes and indeed, is often cited on here as a reason to use a registered spark as its more economical.

The original question was purely out of interest.

Im still not clear what legal obligation exists that prevents someone doing a change such as this. Yes, i understand that testing needs to take place. If a person is competent it seems to me there is nothing to prevent them doing this work, legally at least.. i.e. enforceable.

 

[JohnW2]

Im still not clear what legal obligation exists that prevents someone doing a change such as this. Yes, i understand that testing needs to take place. If a person is competent it seems to me there is nothing to prevent them doing this work, legally at least.. i.e. enforceable.

That all depends on the outcome of the debate you see going on here. If the work is notifiable, then it woul be unlawful to undertake it without notifying (which, as mentioned, is an expensive business for someone not registered with a scheme).

Kind Regards, John.

 

[sparkticus]

Im still not clear what legal obligation exists that prevents someone doing a change such as this. Yes, i understand that testing needs to take place. If a person is competent it seems to me there is nothing to prevent them doing this work, legally at least.. i.e. enforceable.

Well join the club, I thought I was clear and now I am not so sure. My personal view is that changing some of the essential characteristics of a consumer unit is barely (if at all) any different from changing the consumer unit and that is not to mention the possible effect on the final circuit. To me that is a logical and common sense conclusion but to be fair that may not be a definition accepted by the building regs or by others.

 

[JohnW2]

John, Under the new 2010 version of the Building Regulations which came into force a few months ago the notification exemptions are now contained within schedule 4:
http://www.legislation.gov.uk/uksi/2010/2214/schedule/4/made
Not that it changes the points both you and I are making.

Yes, I was talking about the 2010 regs, but inadvertently talked of the Schedule number in 'old money'.

...and, in passing, I've often wondered ... what on earth is 1(h) doing there??

The new schedule 4 groups together all exemptions from notification for the entire set of building regulations, not just Part P. Clauses 1(j) through 1(m) also relate to non-electrical items.

Ah - I hadn't twigged that. As you probably realised, despite what I typed, I didn't mean just 1(h) - I meant "1(h) et seq." - and was wondering what these things were doing in what I had thought (incorrectly) only related to Part P. Thanks for pointing that out.

Kind Regards, John.

 

[sparkiemike]

1) is changing a whole consumer unit notifiable?

Yes

2) if 1) is notifiable then what is the definition of changing a consumer unit?

In my opinon it is when you remove the old consumer unit/fuseboard so just the cables are left and replace it with a new one

3) what is the difference between changing a consumer unit and changing the essential characteristics of a consumer unit?

See above

4) would anyone regard changing an MCB for an RCBO on any circuit as altering the characteristics of that circuit?

No, not really a RCBO has the same characteristics as a MCB, in addition it also has RCD characterisitcs. Is the RCD part of the RCBO provding fault protection or additional protection? If it is just additional protection then max EFLI values remain the same.

5) would anyone regard changing an MCB for an RCBO as re-designing the related final circuit?

No, if you added a stand alone RCD for a single circuit or even a SFCU RCD would you notify that?

 

[SimonH2]

It costs £2.50 to notify

It will cost a whole lot more than that if you're not registered under one of the appropriate schemes.

Too f**ing right it does !
In my area, it's £150 for electrical works IF you can provide them with the right test results. Since few DIYer will have the equipment for that, it then becomes about £225.

4) would anyone regard changing an MCB for an RCBO on any circuit as altering the characteristics of that circuit?

5) would anyone regard changing an MCB for an RCBO as re-designing the related final circuit?

No and No
Look at it this way - before you had an MCB, almost certainly type B, and of a specific current rating.
Afterwards, you still have an MCB, type B, and of the same current rating.

So from the POV of circuit protection, nothing has changed.

You have ADDED RCD protection to the circuit, but I cannot see any way in which that could adversely affect anything - other than nuisance tripping if there is any leakage current.

So I'd consider that provided the type and current rating are the same, then there is no way that swapping an MCB to an MCB+RCD (ie RCBO) could be construed as altering the protection characteristics or re-designing the circuit.


In fact I did consider doing just that - swapping out all the MCBs for MCBOs in the existing board. But in the end I decided it would have been too tight, and I wanted to add spare ways anyway. So I came to an arrangement with a friendly spark to do it.


I can see some logic why changing an MCB or swapping one for an RCBO would be allowed but changing the whole CU is not. The difference is in having to disconnect the main supply upstream of the main switch. Since many (most ?) installations don't have an isolator between meter and CU, some people would be tempted to do it with the tails live.
In fact, many years ago I know someone who was renovating an old house - and he moved the meter. Dropped the supply cable out, taped up the live core while he was ripping the house to bits, and then put it back together again afterwards.
Back then I didn't know enough to tell him to leave well alone.


Supplementary question ...
If swapping out breakers (whether like-for-like or MCB to RCBO), is it considered acceptable or not to use a different make of breaker ? I can't see any logical reason not to when they are of the same design - ie they fit just the same as the original make.

 

[Paul_C]

You see, I am struggling with this:

C) re-fixing or replacing enclosures of existing installation components, where the circuit protective measures are unaffected;

To me, despite that it relates to "enclosures" by implication it suggests that any change of protective devices that are not literally one for one in performance and capability is notifiable.

You have to read each of the sub clauses as if it were a separate item. If any one matches the work you are doing, then it's exempt from notification.

So to take 1(c), you read it as "Work consisting of re-fixing or replacing enclosures of existing installation components, where the circuit protective measures are unaffected." If the work matches that description, it's not notifiable. So if the circuit protective measures are affected by the work of re-fixing or replacing the enclosure, it's not exempt.

Now read 1(a) the same way: "Work consisting of replacing any fixed electrical equipment which does not include the provision of any new fixed cabling, or a consumer unit." There is no mention about whether circuit protective measures are affected or not, so it's immaterial. So long as the work consists of replacing fixed equipment and does not include the provision of new fixed cabling or the provision of a consumer unit, it's not notifiable.

How does anything below specifically exclude circuit protective devices?

1. Work consisting of—
(a) replacing any fixed electrical equipment which does not include the provision of—
(i) any new fixed cabling, or
(ii) a consumer unit;

What am I missing (and I may well be missing something)?

There is no specific exclusion relating to circuit protective devices, but there doesn't need to be. The fact that those protective measures are mentioned in 1(c) has no bearing on the way that you read 1(a).

1) is changing a whole consumer unit notifiable?

It involves the provision of a consumer unit, so yes.

2) if 1) is notifiable then what is the definition of changing a consumer unit?

The fitting of a new unit as a complete replacement for the old one?

3) what is the difference between changing a consumer unit and changing the essential characteristics of a consumer unit?

In electrical terms, very little. In terms of the Building Regulations, one is the provision of a consumer unit and the other is merely replacing component parts of it. Daft? Undoubtedly.

4) would anyone regard changing an MCB for an RCBO on any circuit as altering the characteristics of that circuit?

Yes.

5) would anyone regard changing an MCB for an RCBO as re-designing the related final circuit?

And yes. But the way the exemptions in schedule 4 are written, that doesn't matter.