Cables and trunking.

[john102956]

Hello. Could anyone tell me what would be the best size plastic trunking for 2.5mm square cable internally? my guess is probably 16mm square but not sure.
Thanks for your help.

 

[Lister1987]

16x25 should fit 2x T&E although check OSG for capacities

 

[littlespark]

16x16 is big enough for 2.5 t&e, if it’s a straight run.... no bends.

25 x 16 gives a little more room.... 2 cables, again, if it’s a straight run.

Correct fixings required to prevent premature collapse in case of fire.

 

[Dustydazzler]

Never use T1 so T2 would be my choice

 

[john102956]

16x25 should fit 2x T&E although check OSG for capacities

Hello. Thanks for that good answer. Could you tell what would be suitable size trunking when using 1.5mm flex cable? Thanks for your help.

 

[john102956]

16x16 is big enough for 2.5 t&e, if it’s a straight run.... no bends.

25 x 16 gives a little more room.... 2 cables, again, if it’s a straight run.

Correct fixings required to prevent premature collapse in case of fire.

Hello. When using 1.5mm flex cable what would be a suitable size of trunking for this?
Thanks for your help.

 

[SJD]

In the past, I would try use 16x16 for one or even two 2.5mm2, and 2 or even 3 smaller cables. But often there would be tight spots like bends or trying to enter down the side of a pattress. So having used up what stock I had, I now generally use 25x16, saves time trying to get cables to fit properly. Unless there are more cables and something bigger is called for.

 

[DPG]

I think the wider trunking looks neater than the square section stuff.

 

[telectrix]

4 x 2. get anything in there. including the gas and water pipes . even the kitchen sink with a bit of thought.

 

[Zerax]

4 x 2. get anything in there. including the gas and water pipes...

And a wet-pants probably would too !

 

[Spoon]

Also remember that when putting cables in plastic trunking to use fire rated trunking clips.

 

[Dustydazzler]

Also remember that when putting cables in plastic trunking to use fire rated trunking clips.

Only if it’s mounted over a door way ?

 

[littlespark]

Only if it’s mounted over a door way ?

No. I believe it’s anywhere now where the cables collapsing could interfere with firefighters access

 

[Spoon]

Only if it’s mounted over a door way ?

If you look at page 5 of the BBB about changes to the regs, it states:
Regulation 52 l.l 0.202 requires cables to be adequately supported against their premature collapse in the event of a fire and applies throughout the installation, not just in escape routes as previously.

 

[telectrix]

but if said trunking is vertical in the corner of a room, chance of it strangling a firefighter are asm remote as me giving up the smokes and beer. common sense should prevail.

 

[loz2754]

As telectrix says, although the updated reg applies to ALL cable support systems whether or not they are in an escape route, common sense could be used to assess whether a particular length of trunking/cable/conduit would prematurely collapse in the event of a fire.

 

[telectrix]

you could get round that reg. by whacking it on with clout nails.

 

[Lister1987]

you could get round that reg. by whacking it on with clout nails.

I just whack a penny washer on the screw that screws the trunking to the wall, 2 birds...

 

[stevethesparks]

I just whack a penny washer on the screw that screws the trunking to the wall, 2 birds...

That wont be substantial, what's to stop the cabling falling out when the lid melts off?

 

[Dustydazzler]

That wont be substantial, what's to stop the cabling falling out when the lid melts off?

I think they pinch the cable underneath the washer...