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.