What wire to use for outdoor light

[unclebob1]

Morning all,
I'm looking to install an LED Flood Light linked to a PIR on the front of my house, the Light itself will be hung off a window frame on the first floor, the pir will be in the fascia of the porch.

I've drawn a rough route i was thinking of taking the wire:

Untitled

• unclebob1
• 25 Apr 2014
• 1

LED light is in red, with the proposed wire route in blue.
There is a hole in the side of the porch for the inside wiring so no problems with that. Question i have is, what type of cable can i use for the run? it will be visible so to speak, not chased into the wall.

Sun is at the back of the house, so this side is mainly shaded apart...

 

[PrenticeBoyofDerry]

You have options:
*Twin and earth if contained in conduit.
*Hi-tuf
* or a general purpose, heat resistant, three core flex would serve the purpose.

 

[unclebob1]

You have options:
*Twin and earth if contained in conduit.
*Hi-tuf
* or a general purpose, heat resistant, three core flex would serve the purpose.

For the three core flex, is this suitable?
http://www.toolstation.com/shop/Ele...ant+Flex+3093Y+15mm2+x+50m/d190/sd2730/p80551 in 1.5mm?

 

[PrenticeBoyofDerry]

1.5mm will be a bit overkill, 1.00mm or even 0.75mm should serve your purpose.
http://www.toolstation.com/shop/Ele...nt+Flex+3093Y+075mm2+x+50m/d190/sd2730/p17041

I assume the circuit being used is not greater than 6A.

 

[unclebob1]

1.5mm will be a bit overkill, 1.00mm or even 0.75mm should serve your purpose.
http://www.toolstation.com/shop/Ele...nt+Flex+3093Y+075mm2+x+50m/d190/sd2730/p17041

I assume the circuit being used is not greater than 6A.

Cheers - its a 30w LED flood lamp - 30w at 240v, just over .1amp

 

[Taylortwocities]

Yes, but from where will you be powering the lamp? The lighting circuit will probably have a 6 amp fuse/MCB. A fused spur may have a 13, 5 or 3 amp fuse in it?

The cable needs to be big enough for the fuse size, NOT the size of the load!

 

[unclebob1]

The lighting circuit is 6 amp mcb. .. but I was looking to add a single rcbo in the roof area where the pir light and mains all comes together (just for the pir and led floodlight) which is 6 amp in a single box as the existing setup didn't have any protection. Would it still need a fused spur?

 

[AndyPRK]

That's an expensive solution.
A fused rcd spur maybe a better option mounted somewhere accessible.
Or not bother with an rcd at all which would be my preference and fit a 3a spur unit.

 

[unclebob1]

Cheapest fused spur i found on toolstation:
http://www.toolstation.com/shop/Ele.../SafetySure RCD Spur White/d190/sd2470/p45636
is £16.48

The RCBO + box:

http://www.toolstation.com/shop/Electrical/CED+Consumer+Units/RCBO+6A+30mA+Type+B/d190/sd2979/p40593@£17.93
and the box:
http://www.toolstation.com/shop/Ele...ts/Enclosure+IP20+2+Module/d190/sd2979/p30350@£1.73

so its £16.48 for a rcd fused spur 13A 30mA vs £19.66 for RRCBO 6A 30mA Type B...

essentially they will both do the same job, but from my understanding RCBO overall is safer?

or 3amp fused spur ok for outside light if there is NO RCD protection at the consumer unit?

 

[AndyPRK]

Ok so the enclosure is cheaper than I expected. Does it have terminals inside?

I was expecting a 2 way mini cu to be used.

An rcbo is no safer than spur rcd. And doesn't isolate the neutral which is a disadvantage.

Don't see why an rcd is required. Just turn off the spur before changing the bulb.

 

[unclebob1]

I'm sure i read somewhere that due to the actual light being outside that it should be RCD protected?

The CU i don't think it does have terminals inside - i will check when i go get the cable, To be honest there will be a junction box next to it to provide the live to the RCBO, and then another on the other side with the manual switch, PIR and then light feed.

Hopefully the lamp shouldnt be changed any time soon, but given it will be hard wired in, defo will be isolating regardless...

 

[AndyPRK]

See what the experts say.

I would have thought you would be best to save money and have an rcd fitted for the whole house.

An rcbo will have a neutral lead which will need connecting. Not a big deal. Use a terminal block.

 

[JohnW2]

* or a general purpose, heat resistant, three core flex would serve the purpose.

Is it not difficult to keep that neat? I would have expected that, sooner or later, the (horizontal run of) flex would start sagging between clips (unless there was a ludicrous number of them)?

Kind Regards, John

 

[unclebob1]

anyone able to advise on best way to protect the circuit? RCD in the consumer unit isnt an option at present, so whatever is advised will be in the "roof" space of the porch.

For info, the power is being taken off the existing light circuit - which is protected by 6amp mcb.

Should i be:

1) putting in an extra RCBO for the pir, switch and LED FloodLamp,
2) Fused RCD for the pir, switch and LED FloodLamp,
3) just a fused spur
4) something else?