Tails - metal board - TT system

[D Skelton]

That's interesting I didn't know that. Bit silly though because to all intents & purposes it has all the fire risks of a DB; Tail terminations carrying the installations full load, a device which incorporates mechanical and electronic components and contacts - all capable of catastrophic failure and subsequent combustion?

Exactly my point lol! The regulation is a joke, hence why I'm still happy to install plastic.

 

[D Skelton]

I wonder what gems they are going to come up with for say corrosive atmospheres and the like where metal enclosures are a complete No, No?? Perhaps contain the metal board within a plastic enclosure???? lol!!

The IET have been led down a path that is going to come back and bite them in the arse!!.....

This does only apply to domestic DBs remember. I can't think off the top of my head where you might have a corrosive environment within a dwelling?

 

[Jonspark]

This does only apply to domestic DBs remember. I can't think off the top of my head where you might have a corrosive environment within a dwelling?

crack house maybe? breaking bad style!

 

[stevey1983]

You can use plastic consumer units so long as its in a fireproof cupboard which eliminates the problem

 

[Plonker 3]

You can use plastic consumer units so long as its in a fireproof cupboard which eliminates the problem

How about installing it correctly and doing away with all this nonsense?

 

[spud1]

You can use plastic consumer units so long as its in a fireproof cupboard which eliminates the problem

Yes you are right although I'm not sure how feasible it will be install a fireproof cupboard every time you encounter a CU change + TT system...

 

[spud1]

How about installing it correctly and doing away with all this nonsense?

What do you mean by install it correctly?

 

[Plonker 3]

What do you mean by install it correctly?

Well for this new reg to be there, it must be because they are not being fitted correctly by everyone isnt it!

 

[trev]

What do you mean by install it correctly?

CU fires are caused by 2 things. Defective materials and poor workmanship. If a metal clad CU is installed poorly then there's still plenty of plastic in there that will melt/burn/give off toxic fumes.
This utter nonsense is the powers that be trying to escape from the fact that what went around is now coming around.

 

[davesparks]

It won't, as it would be a single RCD in an enclosure it wouldn't be a distribution board, therefore it wont be subject to the requirements of that regulation.

But it would be similar switchgear, or whatever the slightly vague description is.

 

[Silly Sausage]

CU fires are caused by 2 things. Defective materials and poor workmanship. If a metal clad CU is installed poorly then there's still plenty of plastic in there that will melt/burn/give off toxic fumes.
This utter nonsense is the powers that be trying to escape from the fact that what went around is now coming around.

It's in the BEAMA statement, non-combustible CUs are being introduced to prevent the spread of fire caused by poorly made terminations!!!!!!
The mind boggles.

 

[D Skelton]

But it would be similar switchgear, or whatever the slightly vague description is.

Yup, hence the pointlessness of all this 'fire resistant' malarkey.

 

[netblindpaul]

It won't, as it would be a single RCD in an enclosure it wouldn't be a distribution board, therefore it wont be subject to the requirements of that regulation.

I wish, not quite though.

The reg, extends to all similar equipment, thus a KMF, a REC2 etc.

However, they don't HAVE to be steel, they just need to meet 61439-3 & shall...
(i) have their enclosure manufactured from non-combustible material,

 

[Silly Sausage]

(i) have their enclosure manufactured from non-combustible material,

Which is?
Can anyone provide a list of suitable materials?

 

[D Skelton]

I wish, not quite though.

The reg, extends to all similar equipment, thus a KMF, a REC2 etc.

And it says this where?

It only mentions distribution boards.

The intent of the regulation may extend as you say, the wording however is all that matters for compliance purposes.

If the wording truly reflected the intent, then on a TT without TN Ze values, you'd be damned if you did and damned if you didn't.

As I keep saying, the departures section of an EIC is there for good reason!

Plastic all the way for me. I don't care what the regs say, you won't find me connecting tails into unprotected metal boards in domestic TT systems.

 

[trev]

Archy, how about rock, preferably igneous. It will melt at high enough temperatures but I don't think a house fire would generate anything high enough.
There may be weight issues for the fixings if granite CUs existed but at least they could be made to look pretty

 

[netblindpaul]

And it says this where?

It only mentions distribution boards.

The intent of the regulation may extend as you say, the wording however is all that matters for compliance purposes.

If the wording truly reflected the intent, then on a TT without TN Ze values, you'd be damned if you did and damned if you didn't.

As I keep saying, the departures section of an EIC is there for good reason!

Plastic all the way for me. I don't care what the regs say, you won't find me connecting tails into metal boards unprotected in domestic TT systems.

In the BYB:

421.1.201 Within domestic (household) premises, consumer units and similar switchgear assemblies shall comply with BS EN 61439-3 and shall:

• (i) have their enclosure manufactured from non-combustible material, or
• (ii) be enclosed in a cabinet or enclosure constructed of non-combustible material and complying with Regulation 132.12.

NOTE 1: Ferrous metal, e.g. steel, is deemed to be an example of a non-combustible material.
NOTE 2: The implementation date for this regulation is the 1st January 2016, but does not preclude compliance with the regulation prior to that date.

BTW, direct copy from the electronic version of the BYB a few seconds ago.
You know the scope of 61439-3
I realise that there are other 61439-* standards, and you could argue that some of them apply.
Also some similar switchgear will be made to alternative -* numbers, there in lies another failing of the reg.

 

[trev]

The thing that boils my wee is, once again, the assumption that somehow electricity used in a domestic environment is somehow more dangerous than that used in a commercial setting.
How many shops have you seen with plastic CUs?
A crap termination is a crap termination. It doesn't matter if the CU is made of bloody asbestos, you cannot make a silk purse out of a pig's ear. There's still going to be combustible material in there that can and will get hot and burn.

 

[Silly Sausage]

Archy, how about rock, preferably igneous. It will melt at high enough temperatures but I don't think a house fire would generate anything high enough.
There may be weight issues for the fixings if granite CUs existed but at least they could be made to look pretty

Aye, that would look nice matching my Brazillian green granite kithen worktops.
I could locate it above the hob.

 

[netblindpaul]

The thing that boils my wee is, once again, the assumption that somehow electricity used in a domestic environment is somehow more dangerous than that used in a commercial setting.
How many shops have you seen with plastic CUs?
A crap termination is a crap termination. It doesn't matter if the CU is made of bloody asbestos, you cannot make a silk purse out of a pig's ear. There's still going to be combustible material in there that can and will get hot and burn.

It is all to do with rescue / escape times in domestic premises, CU's under the stairs etc.