Can I use 0.75mm black pond flex to feed 1000W lights?

[HappyHippyDad]

Hello all....


I am doing some work in a small domestic stables and the chap has now asked if I can fit some extra outside floodlights. There will be two 50W LED flood lights.

In total there will be 20m's of 1.5mm SWA and then a further 8 metres of black flex to them.

There is nothing in manufacturers instructions about which size to use but they have a small tail of 1mm H05RN prewired in.

The voltage drop is fine and 0.75mm flex can take up to 6A which is more than enough (only needs around 0.5A) but it is prewired with 1mm and 0.75mm just seems undersized for 2 big floods.

Am I being over cautious, what size cable would you guys use? The reason I want to use the 0.75mm (H05RN) is thats all I've got handy and screwfix/toolsation dont seem to do any black flex bigger than 0.75mm and they are the only ones open!

 

[MDJ]

The lights are 50 watt not 500, so no problem, just one thing, why 8 mtrs? I would always try to have the flex as short as possible, JMO, it's Sunday and early so I may seem a little touchy LOL

 

[HappyHippyDad]

Thanks MDJ,

Just heading out the door so good to get a quick reply..

Its 8meters as its up a telegraph pole!

 

[Richard Burns]

Black rubber flex is OK, BGB says for fixed wiring is min 1mm, but 0.75 is OK for flex to a light.
B&Q sell black rubber flex up to 2.5mm.
so long as your volt drop for the entire length is OK (which it should be on that current) (but not the 1000W you state in the title!)

 

[Darkwood]

1000W ... they phased out 500w floods 2 yrs ago and lamps too .....where did you get these fittings?

 

[telectrix]

think OP had a finger stutter when typing the title.

 

[HappyHippyDad]

Thanks guys,
I'm not replying as quickly as usual as I'm very busy, hence the finger stutter Telectrix! You're all quite right 100W in total NOT 1000W :6:

I didn't actually get around to doing it anyway as they had so many other jobs for me to do! Going back in august..

Black rubber flex is OK, BGB says for fixed wiring is min 1mm, but 0.75 is OK for flex to a light.
B&Q sell black rubber flex up to 2.5mm.
so long as your volt drop for the entire length is OK (which it should be on that current) (but not the 1000W you state in the title!)

Thanks as usual Richard,

Just out of interest what do you think of using normal black flex outside (i.e H05VV)? From what I've read its not supposed to be used outside but its black so it will repel the UV and I do see it used fairy often, although it is PVC!

 

[Richard Burns]

I would use black flex outside, I would tend to use rubber flex, but no problems with black PVC flex.
I am sure one of the books says do not use white or grey cable outside but black cable has a reasonable life and does not specify material of sheath.
I have also seen installations over twenty years old with grey or white PVC outside that is still fine even if exposed to sunlight (I have also seen ones deteriorating badly) so I have no real worries over PVC.