Main cables going into metal DB

[bluearmy]

Hi all

Haven't posted on here for a while but i'm just wondering if there are any latest regulations that anyone may know about, with regards to putting the main tails into the new metal DB's?

Is it ok to just grommet the holes they are going into? I'm working on a domestic house but am also curious if the regs change from domestic to commercial etc?

Cheers sparkies

 

[telectrix]

you can get flex glands that accomodate all 3 tails. neat and compliant.

https://www.tlc-direct.co.uk/Products/WKTKP40R32.html

 

[bluearmy]

Ah right is it a regulation that it must be done like that or a way similar? A grommet is not acceptable? Cheers for reply btw

 

[Leesparkykent]

Ah right is it a regulation that it must be done like that or a way similar? A grommet is not acceptable? Cheers for reply btw

depends on what surface the tails are entering.

 

[bluearmy]

They are entering a metal DB Lee. There are pre drilled holes in it, 20mm and i think 1 32mm hole in the centre

 

[Leesparkykent]

They are entering a metal DB Lee. There are pre drilled holes in it, 20mm and i think 1 32mm hole in the centre

IP2X sides and bottom and IP4X on the top.

 

[bluearmy]

IP2X sides and bottom and IP4X on the top.

Cheers that's great. I was also thinking if the cables needed securing by the likes of a gland or if they are ok left loose. I know the grommet will prevent any damage but just not sure if a reg says they MUST be secured by the use of anything

 

[davesparks]

Plain old fashioned common sense should be enough to tell you that the tails need to be adequately supported.

If you want to know exactly what the regulations say then buy yourself a copy and read them


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[Leesparkykent]

Cheers that's great. I was also thinking if the cables needed securing by the likes of a gland or if they are ok left loose. I know the grommet will prevent any damage but just not sure if a reg says they MUST be secured by the use of anything

on the bottom surface a suitably sized grommet, bush or tail gland will be fine although manufacturers instructions need to be taken in to account. If the earthing arrangement is TT then IMO it would be prudent to pass the tails through a purpose made nylon tail gland as adds strain relief for the tails. TBH I've stocked up on tail glands so pretty much been using them as my standard method when installing domestic metal AM3 boards.

 

[Leesparkykent]

http://www.remora.net/catalogue/nylon-cable-glands-plugs/GripLoc-Consumer-Unit-Tail-Kits

 

[bigspark17]

Also main earth should be brought through same hole as tails worth noting, see this mistake quite often! Nylon glands are stocked on the van now as gives a profesional and sterdy finish and no argument as to if tail hole is ip2x or ip4x depending on entry surface.

 

[bluearmy]

Cheers lads much appreciated been a great help

Also the reply about getting myself a regs book and reading it, is a valid one. I do have (of course) but i thought that's what this site was about, helping fellow sparks. So i just thought it would save me the time.

Anyway thanks again :flowers:

 

[rich.250]

Also main earth should be brought through same hole as tails worth noting, see this mistake quite often! Nylon glands are stocked on the van now as gives a profesional and sterdy finish and no argument as to if tail hole is ip2x or ip4x depending on entry surface.

Why the earth too?
The earthing conductor should be carrying no current.
So it will not be able to cause an EMF into the metalwork as the neutral could.


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[davesparks]

Why the earth too?
The earthing conductor should be carrying no current.
So it will not be able to cause an EMF into the metalwork as the neutral could.


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Consider what will happen under fault conditions, the earth will be carrying a significant amount of current, certainly enough to cause an appreciable eddy current in the metalwork.

Plus of course there's everyone's favourite reason: because the regulations say you must do it!

 

[Leesparkykent]

Why the earth too?
The earthing conductor should be carrying no current.
So it will not be able to cause an EMF into the metalwork as the neutral could.


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