Help with lighting please
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Acetrickster
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Help with lighting please

by Acetrickster » Mon May 11, 2009 12:51 pm

HI, new to this forum stuff, so sorry in advance for any indescretions. I am looking to run a line of outdoor bulkhead lights (max 60w bulb) along a perimeter wall of my house (cabling inside conduit) and idealy terminate in switched fused spur or plug? the run would be about 60m and I was hoping for a fitting every 4m is this feasable (max 12 lamps), using 1.5mm arctic flex (I already have it) or what would do better. Also if I wanted to fit a photocell switch at the end of run (furthest from the supply) what's the best way for doing it? and can the fittings simply be wired in series?

Thanks in advance.

moggy1968
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by moggy1968 » Mon May 11, 2009 9:22 pm

this work is notifiable, so you either need to employ an electrician who can notify the work, or you will need to notify building control of your intentions BEFORE you start work.
there are a lot of other factors to consider. where will you pick up the feed, is this circuit RCD protected, can it take this kind of increased demand, what is your consumer unit like, is your bonding in place etc etc

bd3cc
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by bd3cc » Mon May 11, 2009 9:49 pm

12x 60w= 3amps on a 240 supply, so fuse plug/sw spur at 5amp.
1.5mm/2 cable ok.
As to Photocell( on during hours of darkness) or PIR (movement sensor), it does depend on what you are trying to do.
Do you want these lights to be on throughout the hours of darkness?
Do you wantto be able to control whether they come on, or not,
Or do you want a movement sensor so that if anyone enters the lights come on, with the option to have them on if you are expecting visitors?
Need a little more info about what you are trying to achieve to help further, but your cable sizes, with the correct fuse rating are fine, and i do not think you should get any significant voltage drop.
HTH

bd3cc
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by bd3cc » Mon May 11, 2009 10:31 pm

Cable size and calculations ok 5amp fuse.
Further description required of what you are trying to achieve, for comments on photocell or PIR?

Acetrickster
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by Acetrickster » Tue May 12, 2009 10:35 am

Thanks for that decided against pir/photocell and am just going with a switched spur. I'm guessing that using singles in the conduit would be better than the arctic? (i.e 3 x 1.5mm/2) and just loop up to each lamp in the run? have settled on 10 lamps across 55 meters max 60w each.?? thanks again

kbrownie
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by kbrownie » Tue May 12, 2009 11:12 am

just to add to info by moggy and bd3cc,
every lamp should be calculated at 100 watts so its 12 x 100watt = 1200/230.
This would be above 5amps only by a small amount but seeing the lights are going to 60 watt would work fine on 5amp RCD fused spur but if 100watt lamp were ever used to replace 60 watts would be over limits, so might need to consider reducing number of lights. Remember part p regs and IP rated fittings and accessories where required.
Lights are parallel not series!
Not what I would consider DIY, best use qualified sparky
KB

bd3cc
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by bd3cc » Wed May 13, 2009 12:04 am

Agree kbrownie, but am also thinking that 100w lamps will be unavailable from Sept., and 60w thereafter.
Any thoughts?
Regards
bd3cc

Acetrickster
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by Acetrickster » Wed May 13, 2009 12:40 pm

Thanks guys think I have settled on 5amp RCD fused spur, 8 lamps and 3x1.5mm/2 single cable inside rigid conduit. I'm gonna do the donkey stuff and my sparky best mate is going to do the important bits and certify. The man from del-monte say.............?

kbrownie
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by kbrownie » Wed May 13, 2009 4:49 pm

Your right bd3cc,
Under a voluntary ban, retailers agreed to stop replenishing stocks of 100 watt and 75 watt lamps at the start of 2009.
By 2010 60 watt bulbs will start to be phased out and all incandescent bulbs will be banned by 2012.
This plan was put in place by the goverment in 2007, hoping consumers would opt for the use of fluorescent lamps.
So taking this on board as an electrician where do we stand as far calculation are concerned on lighting circuit within a domestic property.
The standard has always been each lamp calculated at 100watts and discharge lights x 1.8?
Looks like the calculators will be out and a reaccessment/amendment needed
KB

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