Running 2.5 power cables through a fluroescent light fitting

[barneybodge]

Hi all,

Need a bit of urgent advice on this one.
I have 2 6 foot fluorescent fittings in line on a ceiling with 1.5 mm cables feeding the first and then on to the second (all through 20mm conduit). I need to put a power spur at the other end of the room and the only route I have is to go through the fluorescent light fittings and continue the conduit out the other end.

Am I allowed to do this ? Or does the power cable have to be re routed to avoid going through the light fitting. Its a shame if I have to 'tee off' because the conduit is already looking a bit imposing and im desperatly trying to avoid too much conduit, tees, bends, 90's etc etc.

Cheers

 

[Lectrician]

I wouldnt do it.

Can you run the conduit behind the fitting. Put two through boxes in the conduit run, both alighning with the besa fixings on the rear of the light.

Fix the light to the boxes with M4 brass screws.

 

[barneybodge]

I think your right, im not happy about the 2.5mm cables running tight to the ballast resistors inside the fittings.

Im going to tee off just before the first light and run parallel all the way to the end of the second light and tee back in. Then when the diffusers go on the lights they should hide most of the second piece of conduit.

Speaking of conduit, thank god I bought one of those plastic draw coils for threading up to 9 cables through one piece of 20mm ! Invaluable tool.

Cheers

 

[dw3101]

9 cables in 20mm

 

[barneybodge]

9 cables in 20mm

Amazing how the little threader pulled the whole lot through 4 90's for a total of 35 feet in one go

And of course, all this work was carried out and finished before 01/01/05

 

[Lectrician]

Regs allow a total of 180deg between circ boxes / inspection bends / accessories.

So,

2 x 90deg
1 x 90deg, 2 x 45deg sets

etc, etc.

Also, spacing factors play a part when filling conduits!!

 

[barneybodge]

Im in line with regs then, loads of circ boxes and no runs with more than 180 total between boxes.

I wonder what regs would have to say about my initial comment of using the fluorescent box as a 'through route' ?

 

[Lectrician]

I dont think the regs say "dont use a flourescent fitting as an enclosure for a wiring system"

But

External Influence plays a part - the heat from the choke in the fitting for example.

Also, common sense - what happens when the flourescent needs replacing (which it will before the wiring system does)

 

[dw3101]

isnt it that you can fill conduit up to 40% Or is it 60%?

 

[barneybodge]

Also, common sense - what happens when the flourescent needs replacing (which it will before the wiring system does)

Very good point, cant believe I missed that but I do call myself barney bodge It would have looked very neat and tidy but would only annoy me greatly when I have to replace the fitting, or replace the power circuit when it melts from excess heat created by the resistors.

Thanks for the help chaps, very handy forum which I hope is even more handy when I find loads of earth leaks !

 

[andy]

isnt it that you can fill conduit up to 40% Or is it 60%?

there are tables in the OSG for what cables can go in conduit