Exterior wiring

[Ian]

Hi

I'd like to install a couple of outside lights on the side of our house

- nothing fancy, just a couple of those bulkhead lights or something to light up what is currently at night a pitch black path from the back door to the dustbin. I would like to minimise internal disruption when wiring these up which basically means running most of the wiring externally, clipped to the outside wall. It's just the side of the house so I'm not bothered about the aesthetics.

I've done plenty of basic internal electrics - adding new lights & sockets etc. - so I know how to do this in principle, but I'd like some advice on materials & regulations for this particular job.

The questions that spring to mind are:

- Type of cable to use? Presumably weather-resistant, able to withstand a range of temperatures, maybe armoured as liable to get knocked on odd occasions?

- Best sort of fixings to use?

- Any regulations regarding positioning of cable runs?

- How to weatherproof the holes where the cable enters the house/necessity to do so?

- I am assuming I can wire this into one of my existing lighting circuits?

- Any other issues I have not considered?

Any advice gratefully accepted.

Thanks.

Ian

[Terry D]

I installed two 500W PIR lights using a switched fused spur from a socket in my bedroom. The wiring from the spur (2.5mm T & E) goes into the loft and the lights are wired in parallel from junction boxes. Drill through the wall above each light position. Use normal round PVC twin & earth flex and use silicone sealant on the exit holes. The advantage of my arrangement is that the switch is above my bed and I can activate the lights immediately in an emergency. Perhaps a better idea might be to locate a lighting supply in your loft, but I would still recommend installing a switch somewhere in the circuit.

Terry D.

[PoP]

Weather resistant, certainly. But if the cable is going to get knocked on occasion, where exactly are you planning to run this cable????

If the cable is going to get knocked then your light fittings are surely going to be in harms way? Apart from having sensitive elements that will blow at the slightest provocation, these fittings get VERY hot! They have to be mounted high because if you knocked your head on one you'd be suffering from both a bruised forehead and also a very likely burn.

The light fittings must not be fitted immediately under the eaves because of the heat problem - I think the gap is as much as 2 feet away (600mm in that antiquated metric system we use).

Normally these cables drop down from the eaves.

As supplied with the light fitting.

See above.

If dropped from the eaves then you don't need to worry.

Bear in mind that these fittings are (typically) 500W - which is 2 amps worth in real money. A lighting circuit is usually protected to supply 5 amps. So with 2 on the same circuit you might be getting a bit close to the limit.

Location. Make sure that the light generated does not blind a car driver on the local roads. These lights are intense, you wouldn't be able to stare at them without giving your eyes a hard time.

PoP

[John Rumm]

I did exactly as you describe with a pair of bulkhead lamps, and to separate PIRs.

I ran the cable in 20mm heavy guage PVC conduit - looks pretty neat and the bulkhead lights are designed so that side entry of power via conduit is easy. It also saves any worry that you may damage the cable.

I used these - they are seem to be one of the better looking bulkhead lamps:-

- Any regulations regarding positioning of cable runs?

I went for lamps at about 8' - 9' from the ground level - one the side wall of the house - one toward the front and one toward the back. The PIRs placed a couple of meters outside of the lamp positions so that you get a light come on if you walk round the side of the house from the front or the back. Ideal for avoiding walking into my log pile!

The cables run up from their exit through the wall (at about 3') to the same height as the lamps and then run horizontally.

Using the coupler:-

drill / punch a 20mm hole in the bulkhead case and then thread this though. The conduit pushes home firmly into the coupler. I added a small amount of white silicone sealant into the various parts before tightening up.

I wired it to the downstairs lighting circuit - in our case it was easy to drill through near the consumer unit (which is on the inside of the wall to which the lights are fixed). I used a ordinary lighting junction box and switch on the inside (so I can override the PIRs and turn them off completely if required). Then mounted one of these on the outside over the hole I drilled through:-

From there used the conduit (with a 1mm sq T&E inside) out to the two light positions (the cable exit in my case being midway (ish) between the light positions)

Get a bending spring to bend the conduit, you will need a few clamps to hold it to the wall, plus a cover and rubber washer for the conduit junction box. Note the screws for fixing the covers are not included.

A quick review of the screwfix order gives the following order codes which may save you a bit of searching:-

15901, 14832, 14128, 13093, 16493, 12389, 11291, 14678

I was pleasantly surprised to find a 60W bulb in each bulkhead gives plenty of light to illuminate the path etc without blinding you if you look at the lamp itself.

[Dave Liquorice]

Please take note those that fit 500W or even 150W lamps. Though I note that the lamps you fitted don't have a sheild/reflector to stop light going upwards to the sky and being wasted.

[andrewpreece]

Just my point of view, but can I make a plea for you not to use bulkhead lights? They shine light everywhere, up into the sky, and into people's windows. Not a problem for you, but unwanted light from a neighbour can be nearly as annoying as unwanted noise. My suggestion is that you consider the snazzy looking full-cut-off light and integrated PIR fixtures you can get at the DIY places now. You can get 75W, 150W and I think 300W lamps and the lamp and PIR sensors are independently moveable. You won't need 500W with a fixture of this type as the light goes precisely where you want it. They retail at about £10 - £13. I've seen 'em at Homebase and B&Q.

regards,

Andy.

[nightjar]

I use ordinary T&E inside heavy gauge 20mm PVC conduit. Plenty of solvent on the joints and solvent welding the access plates on makes it watertight, but do allow for condensation to drain out somewhere. A 4-5mm hole at the bottom of a run will usually suffice.

I use a mix of low energy floodlights, for area lighting, and cheap bulkehead lights with 9W low energy lamps, for places that need better local lighting, like over a door. You don't need huge amounts of light outside at night. The bulkhead lights I use (from the Massive range) have frosted covers, which can be painted inside with silver paint, to prevent light spread in the wrong directions, without it being obvious when the lights are off.

With PCV conduit, use a joint box with a rear entry and take the conduit right through the wall.

I put 30mA RCBOs on any outside circuit, including the lights.

Colin Bignell

[John Rumm]

I did think about if it was worth finding some other form of luminair (or shielding the ones I used) to cut down on light leakage. In the end I decided that I could cope without, since the eves of our house would stop loss straight up, the gap to the next door property is only 8' or so - so that catches most of the rest. Finally the PIRs are set to keep each light on for only 10 secs or so after activation (and tuned to not activate to often!)

Having said that the light level is helped by both houses being painted a lightish colour - it tends to maximise the effect of the light "captured" between them.

[Mungo Henning]

Hi Ian,

Use TRIPLE and Earth cable for the wiring: live, earth, neutral and also Switched Live. Wire up a double-gang light switch inside the house: the first switch for power to the PIRs so that you can switch them off in high winds, and the second to connect the switched power to the extra wire in the cable so that you can override the PIR sensors when they ultimately fail and it reverts back to a simple on/off light. The bulbs get connected to the Switched Live cable.

Replace all steel screws in the external lights with brass or stainless steel. It may seem a doddle to connect the new light fittings when they are new; just try changing a bulb a year down the line whilst at the top of a ladder and the old screw having rusted into the case! Especially do this to the clip that holds the bulb cover in place. Don't skip this step; it's a pure b*gger and I should know because I've had to change said screws in friends and relatives houses!

Just my tuppence

Mungo

[John Southern]

I like using the GE "light in a box" 2D bulkhead lanterns wich are energy efficant and have a little triangle key to remove the shade to acces the lamp/gear tray. To stop screws rusting up outside the simple answer is to put some grease on it.

Jon.

[Mungo Henning]

If it works for you then who am I to complain. But picture the scene: it's winter time, there's a 30mph howling wind blowing, there's a PIR floodlight mounted about ten feet off the ground, I'm up the ladder with a hacksaw in order to saw through the rusted bolt just to get the glass front open to replace the broken bulb. Of course, as I cut through the rusty bolt the cover falls forward and the glass pirhouettes (sp?) out to meet the concrete some ten feet below it...

Hence the emphasis on ensuring that whatever cover connection is used try and make sure that it will last against the elements. Methinks grease on a 500w light will soon be burnt off, so tis the brass screws for me again.

Mungo

[Ian]

Thanks Terry, but I want to be able to switch this from the kitchen. I am intending to follow up my original posting as I don't think I described it very well to begin with, and also to respond generally to the ideas in this thread.

Ian

[Ian]

Hi PoP

I'm intending to post a followup to my original message that addresses some off your comments and others on this thread. Thanks for taking the trouble to reply.

Ian

[Ian]

Thanks John

This was extremely helpful to me.

Ian

[Ian]

Hi Andy

Thanks for this - the light pollution aspect hadn't really occurred to me. I thought of using bulkheads as (i) they are cheap and (ii) my next door neighbour has one and it seems to work OK on his side of the path.

To be fair there isn't a lot of space between the two houses so most of the light is going to be trapped. But I am interested in your suggestion. Trouble is I'm not really sure what I am looking for. Do I need to go and find something called a 'full-cut-off light' - i.e. does that fully describe what I need to go and buy?

Please not I definitely don't want the security style lights or those naff lantern things.

Thanks,

Ian

[Ian]

Hi Colin

Thanks for the tips.

I must admit I haven't come across RCBOs before - looking on the TLC site it seems to be a combination of a MCB and RCD. What you are saying seems to imply a completely separate circuit. Are there any alternatives to this - e.g. adding some extra protection to a spur taken from an internal ring main circuit or internal lighting circuit.

Ian

[Ian]

Thanks Jon,

Are these lights widely available - or is there somewhere online I can get them. I didn't see them on TLC, but I didn't have time for a good look.

Ian

[Ian]

Many thanks to all who have replied to this thread. I realise from some of the replies that my description of what I want to achieve could have been clearer so I'm replying to my own original message.

First of all, these are not security lights and there was never any requirement for the high wattage halogen type things - I just want a bit of light so that I can take something out the back to the bin at night without stepping in dog poo (our dog has access to the outside via a flap on the back door).

Secondly, I had never really considered using PIRs - I imagined having a switch next to the back door, though the replies I have received have given me cause to reconsider this. Even so, I want it to be possible to switch the light on or off (overriding any PIR) from somewhere in the kitchen, even if it is not as convenient as being a switch next to the door. This, together with the requirement that there be minimal internal disruption is what led me to the conclusion that most of the runs of wiring need to be on the outside and why the approach that was suggested of dropping the wiring down from the eaves would not work

- there is no easy way internally to get cable from the loft to the kitchen.

Perhaps I should explain my original intention a bit better. The door is on the side of the house. The understairs cupboard ('pantry') is accessed from the kitchen and is where the consumer unit is located. One of the walls of this cupboard is part of the side wall of the house. What I had therefore imagined doing was to effectively add a couple of lights to the downstairs light circuit, with the cables on the outside of the house, only entering for the switch next to the back door and into the pantry to connect into the circuit.

This would have entailed a couple of vertical runs of cable that would enter the house at a relatively low level. It is these that I was particularly concerned might get knocked occasionally. (The sort of situation I have in mind is where I am carrying an armful of prunings from the back garden down the side path to the front of the house. My experience is that they tend to scrape along the wall, and catch on obstacles, though the force they exert is not immense.)

If I go with the PIR idea and forget about the need for a convenient switch next to the back door, I can get this down to one vertical run that enters at the top of the pantry (about 5 feet off the ground). I can put a slightly less convenient switch in the pantry for overriding when I need it, but rely on the PIRs for day-to-day convenience. Also, I can run this vertical cable behind the soil pipe, so it should be pretty well protected.

In the light of the helpful replies (thanks to John in particular for the screwfix details), I will use heavy duty PVC trunking. Is the screwfix stuff definitely suitable for exterior use? Also, it was suggested to use standard cable inside trunking - is this OK? As far as I can see, only the temperature aspect of the weather will have a bearing.

I'd like to take on board the comments about light pollution from the bulkhead style lights. However, I would re-iterate that these lights are to go on the side of the house. Also, next door is about 7 ft away, so the light is not going to get much chance to 'escape', and next door already have a light of this type. They will only be switched on for short periods anyway. Having said this, I'll look into the "light in a box" that Jon recommended, and the units that Andy recommended.

Thanks once again for all the help - brilliant response as usual.

- Ian

[Ian]

Hi Andy

Thanks for this - the light pollution aspect hadn't really occurred to me. I thought of using bulkheads as (i) they are cheap and (ii) my next door neighbour has one and it seems to work OK on his side of the path.

To be fair there isn't a lot of space between the two houses so most of the light is going to be trapped. But I am interested in your suggestion. Trouble is I'm not really sure what I am looking for. Do I need to go and find something called a 'full-cut-off light' - i.e. does that fully describe what I need to go and buy?

Please not I definitely don't want the security style lights or those naff lantern things.

Thanks,

Ian

[nightjar]

Exactly.

Certainly you could fit a 30mA RCD onto an existing circuit, although I would never run lights off a ring main. The MCB will not protect 1.0mm or

1.5mm cable, while 2.5mm cable can be difficult to use in many light fittings. It can also be confusing to someone coming after you to have to isolate a ring main to be able to work on a light.

I prefer to have a number of different circuits, so that tripping any protection will only take out a fairly small part of the system. That is also why I use RCBOs on individual circuits, rather than MCBs run off a common RCD.

Colin Bignell