Two cables through conduit

[chris gray]

We did a school last year where the architect had designed lighting in 2.5 lsf. Just a nightmare

 

[chris gray]

We did a school last year where the architect had designed lighting in 2.5 lsf. Just a nightmare

 

[buzzlightyear]

can you repeat that CG, I missed that .

 

[Risteard]

Yellow 77 is good for conduit. Again singles are the correct cable type for a containment system like this though.

 

[buzzlightyear]

We did a school last year where it burned down from the lighting in bell wirer , Just a nightmare.

 

[Marvo]

I know in our local regs (non-UK) there's a maximum percentage you can fill a conduit because the current rating afforded to cables installed by this method rely on there being some air flow through the conduit. I've got a vague recollection from a thread on this forum a few years ago that there's a similar reg in the UK as well.

 

[buzzlightyear]

https://www.rm-electrical.com/wp-co...uit-Trunking-Capacity-Chart-RM-Technical1.pdf

 

[Marvo]

For bonus points Buzz, have you got a UK regulation number?

 

[buzzlightyear]

1. Where it is intended to connect the cables in this table to equipment or accessories designed to operate at a temperature lower than the maximum operating temperature of the cable, the cables should be rated at the maximum operating temperature of the equipment or accessory (see Regulation 512.1.5).
2. Where it is intended to group a cable in this table with other cables, the cable should be rated at the lowest of the maximum operating temperatures of any of the cables in the group (see Regulation 512.1.5).
3. For cables having flexible conductors see section 2.4 of this appendix for adjustment factors for current-carrying capacity and voltage drop.

 

[PEG]

it will go in a treat.

....Just because you CAN fit something,somewhere....does not mean it is either necessary or enjoyable (Hypocrates 2nd law)

 

[Wilko]

Hi - the OSG Appendix E has the numbers and reminds us to look at Reg 523.5 (rating factors for cable grouping).

My take is these conduit factors are about good practice that is likely to not result in damaged cables during installation. But the designer still needs to ensure the appropriate CCC de-rating factors are used when grouping the conductors.

 

[buzzlightyear]

PEG ,at the xmas market at your neck of the woods.

 

[jay sean]

yellow 66

 

[Risteard]

yellow 66

Is that a cheaper version of Yellow 77?

 

[PEG]

PEG ,at the xmas market at your neck of the woods.

Aaahhh,the joy of the season...the festive weapons search...the sniffer dogs...the vehicle proof perimeter...Wonder,at the hand-made Bavarian wooden toys,made in India...the Dutch pancake seller,who occasionally lapses back to his native Salford accent...dodge the yuletide pickpockets...watch the drunken,marital brawl...absorb the splendour of scouse santa hat vendor,and his well hidden permit...slide away,and relax as you set off half-way home,on an overloaded tram,where abuse and threats from armed youths,entertain you,before discharging in to a packed car-park,where your vehicles side window's shattered glass,glistens like a Winter morn...
I LOVE this town,and this time of year is always so special

(Brought to you by MAIM, Manchester Authority on Investigating Merriment)