Daisy-Chaining Lights

[dk1uk]

Hi – I'm hoping for some advice please.

Outside my back door is currently a wall-light. There's a double-switch by the back door – one for the interior kitchen light and one for the light outside the back door.

I want to replace the outside light with a new light with a PIR sensor. Easy.

However, what I would also like to do is run a length of cable from that new light to another new PIR light that I want to install a few metres away to also provide lighting to the side of my house for security. Ideally the PIR sensors would work independently. Is this a bad idea or perfectly acceptable?

If this is allowed/possible, then aside from working out the wattage and thus whether I can add the addition load to the circuit, please can you advise if there's anything else that I need to think about? For example, the type of cable I should use bearing in mind it will be open to the elements?

Many thanks in advance.

 

[riveralt]

We tend to get shouted at by those who must be obeyed if we use the word d***y c****s.

I will assume - but you need to check that your current outside light has a switch live, neutral and earth.
If so then your first light with PIR will wire up as normal - using the live neutral and earth terminals. With luck you may be able to run the rubber 2 Core and Earth cable from the first light enclosure to the second light.
If so then the rubber cable's live, neutral and earth goes in the live neutral and earth from the first light to the LNE in the second light.
If you cannot fit the two cables in the first light enclosure then you may need to utilise an IP rated junction box and run the switch cable to it and from the JB to the first and second light.

 

[dk1uk]

Thanks a lot for the reply. I'll check the wiring before starting.

Thanks again.

 

[PrenticeBoyofDerry]

If you intend to install outside lights, it would be wise to consider double pole switch/isolator, that will separate/disconnect the main house electrics to the external lights. This will help prevent power loss within the house if either of the external lights/cable becomes faulty.
But your existing set up, may not make this easy.

 

[dk1uk]

Thank you.

Any advice on the type of cable? I searched for rubber cable and could only find this http://www.screwfix.com/p/3-core-rubber-pond-flex-3183p-0-75mm-25m/61627

There's also this armoured cable, but I've no idea which thickness of 3-core I should get? http://www.screwfix.com/c/electrical-lighting/armoured-cable/cat830462

Will the rubber stuff suffice or should I be looking at the armoured version?

Many thanks

 

[PrenticeBoyofDerry]

Hituf would be ideal, you could also run in conduit.
1.00mm or 1,5mm 3 core, should be okay.
If the cable is not routed in an area where it requires mechanical protection, I would not use SWA.
You require cable that is suitable for the external environment;
So protection against sunlight and frost is important.

 

[riveralt]

You don't need Hituf - (it is expensive) unless you are running it in areas where the cable could be damaged - just standard black rubber cable - I would get the amount you need from your local electrical store - where your local sparks go.
Don't go to a shed because they will only sell it in min amounts and charge you a lot.
3 core .75mm ² or 1mm ² is more than enough unless you intend to put seriously large wattage lamps in your lights.

 

[dk1uk]

Thanks again - .75mm would be OK for say 200w?

Thanks

 

[riveralt]

Thanks again - .75mm would be OK for say 200w?

Thanks

Yes

 

[ban-all-sheds]

You don't need Hituf - (it is expensive)

It's also a bit of a b***er to work with - very inflexible.

 

[ericmark]

1. Some lights with PIR sensors are set by switching supply on and off which is all well and good with one outside light but with two it can make it impossible to set. Depends on PIR used of course.
2. The lights can play silly with each other. Next door fitted a PIR controlled light and I have a PIR controlled light if I switch mine on they go into Christmas lights mode. Mine activates next doors which switches off mine as next doors switches off mine switches on etc.

Also central heating outlets, tumble drier outlets, local cat can all set off a PIR and however much one tries to think about it often something changes and the lights goes crazy. So I would always include an option to isolate any outside light be it going crazy or getting water inside they really need a double pole switch each. I have one where the CFU welded onto the contacts going short circuit cheap Ikea bulbs.

With cheap LED bulbs I do question PIR control I used a PIR down side of the house so I could go to back door at night now I use a LED bulb with just a light sensor and it stays on all night.

 

[dk1uk]

Hi - so from a load perspective, I've checked and the circuit is on a 6amp fuse in consumer unit. On the circuit are:

10 x 50W downlights (the 12v type)
2 x 60W bulbs

I realise this might be a really basic question for some but just to be safe...

My understanding is that I can run up to 1,380W on a 6amp circuit. Given that what I already have adds to 620W, I can easily add another 200W outdoor light without any worries?

Many thanks

 

[dk1uk]

Hi - anyone?

I'm hoping to get this done today.

Also daisy-chaining the second light won't overload the existing lighting cable?

Many thanks

 

[ban-all-sheds]

I can easily add another 200W outdoor light without any worries?

Electrically? Yes.

Legally? No - you aren't allowed 200W lights.

 

[dk1uk]

Hi - I've bought a 150W floodlight with PIR sensor. I'm potentially not allowed this??