Flex or Twin & Earth?

[jazzyb88]

Hi,

I am looking to wire up an outside light within the next few months (PIR flood light, 400w). I was hoping to create a spur off the lighting circuit (protected by 5amp fuse) in the loft - once i calculate the amp draw of the light itself - and then run cable outside the house to the light fixing.

I'm just wondering whether 1.5mm t&e would be suitable for being used outside or should i go with flex as it's meant to be more 'durable'? T&E seems to be pretty cheap, but i don't mind extending to flex if it will be better!

Cheers.

 

[davy_owen_88]

Hi,

I am looking to wire up an outside light within the next few months (PIR flood light, 400w). I was hoping to create a spur off the lighting circuit in the loft (once i calculate the amp draw of the light) and then run cable outside the house to the light fixing.

I'm just wondering whether 1.5mm t&e would be suitable for being used outside or should i go with flex as it's meant to be more 'durable'? T&E seems to be pretty cheap, but i don't mind extending to flex if it will be better!

Cheers.

T&E is fine if it is protected from the sunlight (inside conduit etc) because the sun causes the plasticisers in the insulation to breakdown and this leads to the insulation becoming brittle which can lead to problems further down the line.

An outdoor flex such as Hituf would be a good choice.

Oh, and do you really need a 400w motion activated floodlight? Your neighbours will not thank you for it when a cat sets it off and it lights up their entire house up just as they are trying to get to sleep, not to mention the fact they are pretty inefficient.

 

[NewOrder]

A 150w unit should be all you need they are very bright, I am actually taking ours down and replacing it with a very dim solar one.

Don't all out door circuits need to be protected by an RCD or does that only apply to things like sockets etc?

 

[jazzyb88]

Hi,

Thanks for the quick reply. If i used T&E in the location i'm thinking, then yes, it should be protected from sunlight. Shame i didn't check tlc-direct more thoroughly as i literally just placed an order with them! May pick up some cable from their local branch in that case.

As for the 400w bulb: good shout . It's the standard bulb that came with the unit (was on offer) but there shouldn't be a reason why i can't change it for a 150w. Generally, the light will be left off. I'm only planning to use it when i need access to the garden e.g. moving bins out to the front.

Thanks again.

 

[jazzyb88]

A 150w unit should be all you need they are very bright, I am actually taking ours down and replacing it with a very dim solar one.

Don't all out door circuits need to be protected by an RCD or does that only apply to things like sockets etc?

Yes, i will be using a switch with 5amp fuse fitted. I trust that would be sufficient?

 

[NewOrder]

I don't have a copy of the 17th edition and I am not a spark so I could not say, but a 5 amp fuse is not the same as an RCD, it will not protect you from an electric shock like an RCD would.

Also if you get the 150w version then a 3 amp fuse would be better I would have thought.

 

[JohnD]

you are required to have an RCD on sockets for outdoor use, but not lighting. you are not expected to be holding the lights in your hand when they are switched on.

 

[jazzyb88]

Also if you get the 150w version then a 3 amp fuse would be better I would have thought.

Yes, good point.

you are required to have an RCD on sockets for outdoor use, but not lighting. you are not expected to be holding the lights in your hand when they are switched on.

Thanks for the quick update.

 

[NewOrder]

Thanks for clearing that up .

 

[JohnD]

shouldn't be a reason why i can't change it for a 150w.

the 150W halogen tube is smaller and doesn't fit

 

[jazzyb88]

shouldn't be a reason why i can't change it for a 150w.

the 150W halogen tube is smaller and doesn't fit

And there in which lies the reason why it was on offer i guess!

 

[mattylad]

A 150w fitting and a 400/500w fitting take completely different sized bulbs.
This is for a good reason, so that you cannot put the higher wattage one in the smaller fitting.

You will find that the smaller 150w fittings are generally a lot cheaper.

How/where are you intending to install the on/off bypass switch if your obtaining power from the loft lighting circuitry? are you switching it on/off via the loft?

A high up 150w, pointing down illuminates extremely well & is more than adequate for most households. It will also save you 350w from off your bills. (it amazes me how many houses have these on almost constantly, the leccy bill must be horrific).

When lining it up, if you have neighbours over the road please ensure that your not lighting up their bedroom/lounge every time it comes on.

PS, make sure that whatever fixings you use are rustproof and that you will be able to remove them in 12 months+ time, these things are notorious for filling with water, going POP and not working. My employers throw a pallet of them away every few months that are returns.

 

[jazzyb88]

In that case, i may buy a 150w unit as well. The 400w was on offer for about £5 at Focus a while back. I'm intending to run a cable from the loft, then drill a hole in the downstairs room directly below where the fitting will go. From there, add the switch and then from there, run another cable up to the light.

I will be definitely be sure to mount the light so that it does not disturb the neighbours, but like i said, i'd only be using it for very small periods of time.

Galvanised screws are at the ready I fully understand what you are saying because when i moved into the property, there was a (dead) security light at the front with rusted fittings that were a nightmare to get off!

 

[RF Lighting]

You can get 150W halogen lamps which are 117mm long, and will fit directly into a 500W style fitting.

http://www.tlc-direct.co.uk/Products/LATH150L.html

 

[JohnD]

galvanised screws will last a short while before the zinc corrodes away.

stainless screws are very much better

brass ones will last but are weak