Fuse Box Replacement

[Fleeting]

There is no requirement to make cable entries flame proof, the enclosure is not fire rated. The Regulations merely state the enclosure should be manufactured from non-combustible materials it makes no mention of added accessories. If the enclosure were fire rated then it would have several approval body markings on it to identify it as such.

 

[SPECIAL LOCATION]

Quick google suggests a typical bog standard non-metal gland is fire retardant....   

https://www.screwfix.com/p/british-general-plastic-gland-kit-2-x-2-5mm-flat-cable/5775p 

There really is way too much over-complicating, and over thinking the non-combustible enclosure issue!

:C   

 

[Fleeting]

The simplistic way of looking at it is that the enclosure should not promote/spread fire hence a metallic enclosure or containing a plastic consumer unit in a metal enclosure. You need three things to aid fire, fuel, heat and oxygen remove any one of those and the fire cannot happen, plastic consumer units are the fuel so replacing it with metal removes one of the elements needed for fire. Consider fire extinguishers, water removes heat and foam removes oxygen these are the basic principles for fire exhaustion. 

 

[OnOff]

The simplistic way of looking at it is that the enclosure should not promote/spread fire hence a metallic enclosure or containing a plastic consumer unit in a metal enclosure. You need three things to aid fire, fuel, heat and oxygen remove any one of those and the fire cannot happen, plastic consumer units are the fuel so replacing it with metal removes one of the elements needed for fire. Consider fire extinguishers, water removes heat and foam removes oxygen these are the basic principles for fire exhaustion. 

I reckon you'd argue black is white tbh. If there's a fire you've got your heat & oxygen. More plastic, unless fire retardant is the fuel. 

 

[Murdoch]

The simplistic way of looking at it is that the enclosure should not promote/spread fire hence a metallic enclosure or containing a plastic consumer unit in a metal enclosure. You need three things to aid fire, fuel, heat and oxygen remove any one of those and the fire cannot happen, plastic consumer units are the fuel so replacing it with metal removes one of the elements needed for fire. Consider fire extinguishers, water removes heat and foam removes oxygen these are the basic principles for fire exhaustion. 

I note you still haven't answered my question

 

[Fleeting]

I reckon you'd argue black is white tbh. If there's a fire you've got your heat & oxygen. More plastic, unless fire retardant is the fuel. 

I can't see an argument. Heat and oxygen alone do not burn.

I note you still haven't answered my question

I would use suitable containment or cable glands.

 

[binky]

I would use suitable containment or cable glands.

The cable hole  grommets supplied with many boards, once you have pushed cable through them, leave lots of gaps. You can get keen and use lots of TRS glands, except half the metal boards have insufficient knock-outs to accomodate enough TRS glands. Another favoruite is to run large setion trunking over the knock-outs, but then you have to ask wheter or not said trunking is truly fire retardent (it's supposed to be). So, silicone is just as useful as a way of sealing cable entries as any other method on an exisitng installation, not that I've done that for many years, but beats changing a board unneccessarily at great cost. It's just another way of achieving a suitable IP rating. 

 

[Fleeting]

Whý should the trunking be fire retardant it is not part of the consumer unit.

 

[Murdoch]

MCB's, RCBO's, RCD's and main switches aren't fire retardant either which goes to prove how the lunatics making these decisions are running the BS 7671 asylum

 

[Fleeting]

MCB's, RCBO's, RCD's and main switches aren't fire retardant either which goes to prove how the lunatics making these decisions are running the BS 7671 asylum

Bit negative isn't it.

 

[binky]

Whý should the trunking be fire retardant it is not part of the consumer unit.

Well this is my point, you bang big holes in the sides of the steel box to make inserting cables easy thereby compromising any fire containment, then put a plastic trunking over those holes. The front of metal boards are ftted with an annoying metal flap that drops back down as soon as you let go of it, no doubt to maintain fire protection from buring MCBs, so a 'risk' is clearly deemed to exist that needs to be contained by metal. Can't see a flame deciding not to burn plastic becuase it's 1mm the other side of metal. LIkewise if using the rear knockouts against a lath and plaster wall or wooden board. So the whole metal board thing is a crock of nonsense imho.  

 

[Murdoch]

Bit negative isn't it.

not negative, just a purely realistic view on what’s happening to in industry which I’m thinking you are relatively new to

 

[Fleeting]

not negative, just a purely realistic view on what’s happening to in industry which I’m thinking you are relatively new to

What makes you think I am relatively new to the industry.

Well this is my point, you bang big holes in the sides of the steel box to make inserting cables easy thereby compromising any fire containment, then put a plastic trunking over those holes. The front of metal boards are ftted with an annoying metal flap that drops back down as soon as you let go of it, no doubt to maintain fire protection from buring MCBs, so a 'risk' is clearly deemed to exist that needs to be contained by metal. Can't see a flame deciding not to burn plastic becuase it's 1mm the other side of metal. LIkewise if using the rear knockouts against a lath and plaster wall or wooden board. So the whole metal board thing is a crock of nonsense imho.  

A metal consumer unit is not required to contain a fire it is not a fire proof enclosure, the requirement is it does not aid the spread of fire.

 

[binky]

A metal consumer unit is not required to contain a fire it is not a fire proof enclosure, the requirement is it does not aid the spread of fire.

so if it's full of holes it's basically useless  :^O  They should have indepenedently tested plastic boards for their fire retardency in my opinion, the regs say 'fire retardent material' that does not necessarily mean metal. 

 

[Sharpend]

My car is made of metal but if I set it alight the flames would find a way out of any opening so not convinced by the argument myself. 

 

[SPECIAL LOCATION]

The front of metal boards are ftted with an annoying metal flap that drops back down as soon as you let go of it, no doubt to maintain fire protection from buring MCBs, so a 'risk' is clearly deemed to exist that needs to be contained by metal.

No they are not...

Several manufactures have MCB covers that are hinged at the bottom not the top..

and they are supplied with little bits of plastic to cover the blank slots..!!

e.g. have a look at some Schneider & BG units...

There is nothing stopping the front cover from being left open, completely negating any argument that they must contain fire..

:C

 

[binky]

No they are not...

Several manufactures have MCB covers that are hinged at the bottom not the top..

and they are supplied with little bits of plastic to cover the blank slots..!!

e.g. have a look at some Schneider & BG units...

There is nothing stopping the front cover from being left open, completely negating any argument that they must contain fire..

:C

Only seen the schneider unit with hinge at bottom yesterday. Good point about the nice plastic blanks though! 

 

[Fleeting]

not negative, just a purely realistic view on what’s happening to in industry which I’m thinking you are relatively new to

I note you still haven't answered my question.

 

[Murdoch]

What makes you think I am relatively new to the industry.

gut feeling

 

[Fleeting]

gut feeling

Maybe you need some Gaviscon or Actimel to refresh your gut feelings.