Plastic consumer units and how to code them

[old man sparky]

Electrical Safety First best practice guide 4 allows for C2, C3, or no code depending on various factors.

Which is fine as per the best practice guide. But when your filling the schedule of items. Looking at that schedule 4.4 which says and I quote “condition of enclosure IN TERMS OF FIRE RATING” you have to look at your plastic consumer unit hanging nicely in the hallway and decide. Best practice guide or not. Unless the plastic enclosure is itself, within a non combustible enclosure. (Not seen this myself so far) then I stand by a default C3. If you dont and 6 months later the thing goes up in flames. You've covered yourself. Please dont say if connections have been checked then happy days. Ive seen melted main-switches due to contaminated or worn internal contacts not overload or loose connections. Sorry for waffling I just feel you really have to cover yourself from the way these schedules are worded and how they can leave you exposed if you dont think through the hows and whys. Like I say I haven't seen anyone take the trouble to enclose a pre AMD 3 consumer unit in any type of fireproof material. So why take the gamble when a C3 wont effect the EICRs satisfactory outcome. And gives you as the inspector a level of cover that you wont get by not commenting and putting a simple pass against 4.4

 

[Julie.]

Which is fine as per the best practice guide. But when your filling the schedule of items. Looking at that schedule 4.4 which says and I quote “condition of enclosure IN TERMS OF FIRE RATING” you have to look at your plastic consumer unit hanging nicely in the hallway and decide. Best practice guide or not. Unless the plastic enclosure is itself, within a non combustible enclosure. (Not seen this myself so far) then I stand by a default C3. If you dont and 6 months later the thing goes up in flames. You've covered yourself. Please dont say if connections have been checked then happy days. Ive seen melted main-switches due to contaminated or worn internal contacts not overload or loose connections. Sorry for waffling I just feel you really have to cover yourself from the way these schedules are worded and how they can leave you exposed if you dont think through the hows and whys. Like I say I haven't seen anyone take the trouble to enclose a pre AMD 3 consumer unit in any type of fireproof material. So why take the gamble when a C3 wont effect the EICRs satisfactory outcome. And gives you as the inspector a level of cover that you wont get by not commenting and putting a simple pass against 4.4

But the point is, this is no different from any other regulation, its not animal farm - all regulations are equal , just that some are more equal than others...

Every regulation has the same standing.

Everyone is able to decide on their level of cya and choose to always give some aspect C3, or C2 that is reasonable.

But as far as the regs go, or the standard forms, every regulation is subject to the same selection of responses, it is up to the inspector to decide which one is most applicable based on the specifics of the installation itself.

 

[Dartlec]

I tend to follow the BPG and presumably showing that you have followed that would also be a way of covering yourself if something happened - given that terminal damage should always be a C2 (and any loose terminals fixed at the time), and that is the most likely cause of a consumer unit fire...

Having said that I do usually C3 a CU if it's on the escape route or under a wooden staircase - and sometimes add a recommendation that no combustible materials are stored near it.

I agree that there is a subtle difference between ticking the box and the BPG saying 'no code' - they aren't quite the same thing...

However, I also tend to add comments to my certificates to cover things like that there.... with no code, but COMMENT in the Code box. It can also be covered in the comments on condition of installation too.

Though also quite a few of the installations I've inspected are old enough to pass because they are pre-plastic, so it's clearly going to be decades most likely before plastic boards are a rarity, either way...

 

[Julie.]

I tend to follow the BPG and presumably showing that you have followed that would also be a way of covering yourself if something happened - given that terminal damage should always be a C2 (and any loose terminals fixed at the time), and that is the most likely cause of a consumer unit fire...

Having said that I do usually C3 a CU if it's on the escape route or under a wooden staircase - and sometimes add a recommendation that no combustible materials are stored near it.

I agree that there is a subtle difference between ticking the box and the BPG saying 'no code' - they aren't quite the same thing...

However, I also tend to add comments to my certificates to cover things like that there.... with no code, but COMMENT in the Code box. It can also be covered in the comments on condition of installation too.

Though also quite a few of the installations I've inspected are old enough to pass because they are pre-plastic, so it's clearly going to be decades most likely before plastic boards are a rarity, either way...

I agree I think the bpg is a fair balance, as is the napit guide, I don't agree with all recommendations, especially the napit, but overall OK - I agree with the comments aspect as well.

 

[old man sparky]

In the end it really is down to you. Its your name on the report, so your decision to make. Nappits codebreakers does like to make use of code 2s, more so than the Nic from what Ive seen. Is that a bad thing though. ?? I guess with all these EICRs flying around, time will tell.

 

[Soi disant]

You can't not give it a code if you're doing a BS 7671 compliant EICR, as there's an explicit item in the Schedule

Condition of enclosure(s) in terms of fire rating etc (421.1.6; 421.1.201; 526.5)

So you have no choice about whether or not to compare the enclosure of a CU with the requirements for non-combustibility in 421.1.201.

C2/C3 is the debate, but it has to be one or t'other.

 

[Soi disant]

I find it interesting that we focus on CUs being non-plastic and yet permit things like REC2 Isolators (with or without SPD) and Thier assemblies to be plastic,

I know - it's bonkers - how can anyone say that it's not "similar switchgear"? Some makers, e.g. Lewden, do SPD isolators in metal enclosures (although theirs could usefully be improved with terminal positions and bus-bar interconnections a la REC2SPD).

But then, you say we "permit" them. Nobody has to - they could code a plastic isolator just like they would a plastic CU.

 

[Soi disant]

I don't make a habit of licking cabals, lead cased or not. ?

Plumbers would.

 

[Soi disant]

What about lead sheathed cables ? Mad idea, but it might work...

Isn't a 100m reel of 10mm² T/E heavy enough for you? ?

 

[Soi disant]

As a plastic c/u by definition is not constructed of non combustible material. IMHO.

I don't have the money to buy BSs for fun, but I'd be very surprised if enclosures which complied with BS EN 61439 were not, in sensible real life, non-combustible enough.

But we are where we are.

 

[Soi disant]

I cant see how red and black vs brown and blue can be compared to a consumer unit by virtue of its build material having the ability to contain a fire.

It can't.

So I wouldn't lose any sleep over 5.1. Or not coding it as long as conductors have been correctly connected and identified.

Again, though, not coding it is not an option.

In the schedule:

Identification of conductors (514.3.1)

And 514.3.1 says (with my emphasis)

......cores of cables shall be identified by:
(i) colour as required by Regulation 514.4 and/or
(ii) letters and/or numbers as required by Regulation 514.5

It's a particularly egregious example of why it was wrong to remove C4.

And if an electrician has to be warned by a label that an installation contains wiring to 2 versions of BS 7671, then I would question there competence.

Take a closer look at my avatar ?

 

[Soi disant]

...and yet permit things like REC2 Isolators (with or without SPD) and Thier assemblies to be plastic

And 800KMFs (and all their clones) too.....

 

[Risteard]

C3 by default is understandable (afterall the code is defined as Improvement Recommended); if nothing else it's arse-covering and doesn't fail the EICR; Much like any other nonconformities to current 18th edition; C3 so it's on record in more than just a 'passing comment' and is inkeeping with the purpose of the C3 code - obviously go further attaching relevant regs from 7681, EAWR and that like where appropriate to further explain your engineering judgement.

I find it interesting that we focus on CUs being non-plastic and yet permit things like REC2 Isolators (with or without SPD) and Thier assemblies to be plastic, along with adaptable boxes, for that main being plastic - I believe 5839 makes an stipulation that any junction boxes et all are to be metalic to ensure system integrity bit would have to find out the relevant clauses to confirm.

BS 5839 also requires the connectors to be ceramic (i.e. porcelain) in the junction boxes.

 

[loz2754]

You can't not give it a code if you're doing a BS 7671 compliant EICR, as there's an explicit item in the Schedule

Condition of enclosure(s) in terms of fire rating etc (421.1.6; 421.1.201; 526.5)

So you have no choice about whether or not to compare the enclosure of a CU with the requirements for non-combustibility in 421.1.201.

C2/C3 is the debate, but it has to be one or t'other.

For the schedule of inspections, the choices are Pass, C1, C2, C3, Lim, N/V, N/A.
For this particular item, BPG suggests coding either No code (Pass), C2, or C3.
Notice I use the word "suggests". It's ultimately up to the inspector to decide.

 

[Soi disant]

There are many guides produced by many organisations which contain much guidance, none of it having any authoritative relationship to actual requirements in the regs.

So consider this plastic CU.

1. Is it non-combustible wrt 421.1.201? If no then it does not comply, so it cannot be a "pass". It just cannot.
2. C1/C2/C3 - it can be one of those.
3. LIM - what limitation can you justify for not inspecting the CU?
4. N/V - how do you justify not verifying the condition of the CU?
5. N/A - why would it not be applicable to verify the condition of the CU?

 

[loz2754]

There are many guides produced by many organisations which contain much guidance, none of it having any authoritative relationship to actual requirements in the regs.

So consider this plastic CU.

1. Is it non-combustible wrt 421.1.201? If no then it does not comply, so it cannot be a "pass". It just cannot.
2. C1/C2/C3 - it can be one of those.
3. LIM - what limitation can you justify for not inspecting the CU?
4. N/V - how do you justify not verifying the condition of the CU?
5. N/A - why would it not be applicable to verify the condition of the CU?

I was just replying to your blanket statement that we have no choice, it's either C2 or C3, one or the other, you said...

Also, as an NICEIC Approved Contractor registered on the list of electricians approved to do EICRs, I had to agree to be guided by the BPG 4.

 

[Soi disant]

I was just replying to your blanket statement that we have no choice, it's either C2 or C3, one or the other, you said...

Well, Pass/Acceptable, LIM, N/V, and N/A I was discounting, as per the above, and C1 I was ignoring as that really implies something more than just a plastic box, e.g. the busbar sticking out of a gaping hole.

I still say that for a CU where there is nothing "wrong" with it, which is what I inferred (so apologies if it wasn't what you implied), C2 or C3 is all there is.

Also, as an NICEIC Approved Contractor registered on the list of electricians approved to do EICRs, I had to agree to be guided by the BPG 4.

Does "guided by" mean "slavishly follow"? Can NICIEC really make you say that a CU which does not comply with the combustibility requirements in the Wiring Regulations is acceptable?

 

[Pretty Mouth]

Deleted, posted in error

 

[loz2754]

Well, Pass/Acceptable, LIM, N/V, and N/A I was discounting, as per the above, and C1 I was ignoring as that really implies something more than just a plastic box, e.g. the busbar sticking out of a gaping hole.

I still say that for a CU where there is nothing "wrong" with it, which is what I inferred (so apologies if it wasn't what you implied), C2 or C3 is all there is.


Does "guided by" mean "slavishly follow"? Can NICIEC really make you say that a CU which does not comply with the combustibility requirements in the Wiring Regulations is acceptable?

No it means guided by.
The actuality is that I almost always code a plastic consumer unit as C3. I also always note it in the comments box. I will sometimes give a recommendation by email that it would be beneficial to upgrade the consumer unit, depending on what all the related factors point to. If it warrants a C2 it gets a C2.

I was just pointing out that guidance from official bodies whose membership includes those who write the regulations is there for a reason and should not be dismissed outright. As you suggest, nor should it be slavishly followed.

All of this type of discussion around EICR coding can be helpful to those new to inspection and testing. However I still stand by what I have said several times on this subject, that those doing inspection and testing need experience of the type of installation that they're inspecting, and if they lack the necessary experience, they should not be doing it. But they are. Hence the plethora of bad EICRs we're seeing being churned out.

 

[old man sparky]

There are many guides produced by many organisations which contain much guidance, none of it having any authoritative relationship to actual requirements in the regs.

So consider this plastic CU.

1. Is it non-combustible wrt 421.1.201? If no then it does not comply, so it cannot be a "pass". It just cannot.
2. C1/C2/C3 - it can be one of those.
3. LIM - what limitation can you justify for not inspecting the CU?
4. N/V - how do you justify not verifying the condition of the CU?
5. N/A - why would it not be applicable to verify the condition of the CU?

Hitting the nail right on the head. And my exact point, that its the Inspection schedules wording regarding Section 4 specifically 4.4 That asks you to Judge the consumer unit enclosure in term of fire rating and quoting regulation 421.1.201. That as I have said, takes the judgement away from you and leaves you with no option but to provide a code against a stand alone plastic consumer unit relying on its own enclosure. with C3 at best. When in reality a well installed dual RCD unit (as an example) would probably have bugger all wrong with it, and give many years of trouble free service, as they often do. But because of the way these report schedules are phrased, and to ensure you are covering yourself against this, you simply have to code it. Not your choice, or even your opinion necessarily but that's the road your being taken down. So in a nutshell Schedule 4.4 forces you to code even where advisory bodies say under certain conditions it wouldn't be worthy of a code. And that's contradictory advice IMHO.