Plastic consumer units and how to code them

[old man sparky]

Good old amendment 3 and the demise of all that's plastic, we have seen many discussions on the good old plastic consumer units, so now for those EICR's where plastic has and will be around for quite some time, SO !!
We all seem to have slightly differing views on this, but here goes.
C2 if there are signs of thermal damage ( I think we would all agree with that one)
C3 dependant on certain locations ie only route of escape or under a staircase.
Other than that no code ?? with just an observation ?? Or no code with no comment at all ??
Throwing a spanner into the works, I code 3 ALL plastic consumer units, but why !!
Of course I could just say its my signature and my decision, plus a C3 is not failing the install, but there's another reason.
Before saying, I would be interested to see what your thoughts are, as I think this could prove quite interesting.

 

[Strima]

I tend to make a note of the type and layout of the consumer unit in the general comments box. i.e split load Hager plastic CU.

I only code when I feel it is warranted, not as a default.

 

[Lister1987]

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.

 

[Mike Johnson]

I wonder how long it will be before this goes even further and we have metal MCB's, RCD's, RCBO's and main switch's, even to the extent of T&E being metal sheathed, or maybe back to metal conduit becoming compulsory.

 

[old man sparky]

C3 by default is understandable

I agree ? But WHY ??

 

[Zerax]

I wonder how long it will be before this goes even further and we have metal MCB's, RCD's, RCBO's and main switch's, even to the extent of T&E being metal sheathed, or maybe back to metal conduit becoming compulsory.

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

 

[old man sparky]

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

H&S would have a field day !! Lead poisoning ?

 

[Mike Johnson]

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

 

[Lister1987]

I agree ? But WHY ??

Did you not read the above? Because you are recommending improvement

 

[old man sparky]

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

So you don't strip em with your teeth !! Obviously not old school ??

 

[Mike Johnson]

I am so old school I have worn my teeth out.

 

[old man sparky]

Did you not read the above? Because you are recommending improvement

I did, just wondered if there may have been more to your reply. Nothing more. ??

 

[old man sparky]

Thanks for the replies, as said we all have our reasons for coding these things or not coding as we feel fit.
For what its worth, I like most have seen these reports gain page after page as times gone on. In particular the Inspection schedule has become very comprehensive.
So looking at section 4 and in particular 4.4
I feel where plastic CUs are concerned, we have little choice but to C3 as an absolute minimum. If Regulation 421.1.201 isn't met. ie condition of enclosure in terms of fire rating. Then I will be covering my proverbial. Sometimes I see these schedules as trick question scenarios.
So default Code 3 thankyou IMHO.
As said cover your arse, its your signature.

 

[UNG]

So looking at section 4 and in particular 4.4
I feel where plastic CUs are concerned, we have little choice but to C3 as an absolute minimum. If Regulation 421.1.201 isn't met. ie condition of enclosure in terms of fire rating. Then I will be covering my proverbial. Sometimes I see these schedules as trick question scenarios.
So default Code 3 thankyou IMHO.
As said cover your arse, its your signature.

The condition in terms of fire rating of which "enclosure" are you referring to?

Since January 2016 Amendment No. 3 to BS 7671 (421.1.201)IET Wiring Regulations states that within domestic (household) premises, consumer units and similar switchgear assemblies shall have their enclosures manufactured from non combustible material, or be enclosed in a cabinet or enclosure constructed of non combustible material and comply with product standard BS EN 61439-3.

Not quite sure where a properly fire lined cupboard under the stairs works with BS EN 61439-3

 

[old man sparky]

As per the eicrs section 4 of the schedules 4.4 the consumer units enclosure itself. Granted if its in a non combustible enclosure then the relevant reg would be satisfied and compliant. But most pre AMD 3 consumer units are simply mounted as installed as indeed they would be. But under those conditions the schedule ie 4.4 leaves you with little choice but to give it some code ie 3. As a plastic c/u by definition is not constructed of non combustible material. IMHO.

 

[Julie.]

Thanks for the replies, as said we all have our reasons for coding these things or not coding as we feel fit.
For what its worth, I like most have seen these reports gain page after page as times gone on. In particular the Inspection schedule has become very comprehensive.
So looking at section 4 and in particular 4.4
I feel where plastic CUs are concerned, we have little choice but to C3 as an absolute minimum. If Regulation 421.1.201 isn't met. ie condition of enclosure in terms of fire rating. Then I will be covering my proverbial. Sometimes I see these schedules as trick question scenarios.
So default Code 3 thankyou IMHO.
As said cover your arse, its your signature.

So C3 absolutely as it doesn't 100% comply with 421.1.201 - I understand

So I assume C3 - no question if the installation doesn't comply with 514.4.1 or 514.4.5 as well?

(Cables not coloured blue; brown, black, grey, blue)


Surely if we decide that anything not 100% compliant with the latest standard must be C3 as a minimum, this applies across the board, not just specific areas such as cu's

 

[old man sparky]

So C3 absolutely as it doesn't 100% comply with 421.1.201 - I understand

So I assume C3 - no question if the installation doesn't comply with 514.4.1 or 514.4.5 as well?

(Cables not coloured blue; brown, black, grey, blue)


Surely if we decide that anything not 100% compliant with the latest standard must be C3 as a minimum, this applies across the board, not just specific areas such as cu's

Its the implications as per the schedule and specifically section 4s 4.4 that leaves you with limited options. Its not about retrospective installations. Ie installs that complied with older versions of BS 7671, not necessarily having to comply with latest versions. Its more specific than that. Its about how you respond and classify to that particular section on consumer units and there enclosures. As said I cant see that the way the eicr phrases that particular section gives you much by way of options. I like most have read it many times, and still come to a C3 conclusion in most instances. But then, thats my view, but always interesting to discuss other viewpoints on this. As said we all need to cover ourselves when signing these things.

 

[Julie.]

Its the implications as per the schedule and specifically section 4s 4.4 that leaves you with limited options. Its not about retrospective installations. Ie installs that complied with older versions of BS 7671, not necessarily having to comply with latest versions. Its more specific than that. Its about how you respond and classify to that particular section on consumer units and there enclosures. As said I cant see that the way the eicr phrases that particular section gives you much by way of options. I like most have read it many times, and still come to a C3 conclusion in most instances. But then, thats my view, but always interesting to discuss other viewpoints on this. As said we all need to cover ourselves when signing these things.

Why does it leave you with limited options? 5.1 would leave you with the same options for identification of conductors.

Compliance (or not) with any previous standards does not form part of periodic inspections, the question is: is the installation satisfactory or unsatisfactory? (~ reasonably safe vs unsafe) - the same non-compliance such as premature wiring collapse - it may have been compliant with a previous standard (which is irrelevant) may generate C2, C3, or nothing, - if the cable is unsupported such that failure could cause entrapment - C2 ; if the failure wouldn't case any issue then depending upon the severity it may be C3, or perhaps just an honourable mention.

I see no difference in any other aspect, the plastic cu may be C2, C3, or mention; cable identification perhaps C3 or mention, or nothing at all, cable supports, etc etc.

 

[old man sparky]

Why does it leave you with limited options? 5.1 would leave you with the same options for identification of conductors.

Compliance (or not) with any previous standards does not form part of periodic inspections, the question is: is the installation satisfactory or unsatisfactory? (~ reasonably safe vs unsafe) - the same non-compliance such as premature wiring collapse - it may have been compliant with a previous standard (which is irrelevant) may generate C2, C3, or nothing, - if the cable is unsupported such that failure could cause entrapment - C2 ; if the failure wouldn't case any issue then depending upon the severity it may be C3, or perhaps just an honourable mention.

I see no difference in any other aspect, the plastic cu may be C2, C3, or mention; cable identification perhaps C3 or mention, or nothing at all, cable supports, etc etc.

We differ in our opinions on this one. 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. So I wouldn't lose any sleep over 5.1. Or not coding it as long as conductors have been correctly connected and identified. 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.
Its all about the hows and whys of personal judgements. But I just feel that sometimes, the way these things are written leaves a lot of grey areas.

 

[loz2754]

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

 

[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.