Richard Bustens Posted November 3, 2004 Report Share Posted November 3, 2004 Hi all How do you fit the downlighters in the roof, they say they need 4'' clearance, that is not a problem in itself but do i remove the insulation above them. And what whattage bulbs do you use.? Link to comment Share on other sites More sharing options...
John Orentas Posted November 3, 2004 Report Share Posted November 3, 2004 (edited) Hi Richard. B & Q and other D I Y places sell a hole cutter of the required size that even has a fancy contraption that catches all the dust. They are normally used for plaster ceiling but I know they work equally well with other materials. Cut through the insulation too, as far as you can and finish off with a Stanley knife so you have a neat hole through to the metal. You can then undercut the insulation to give a larger space if you are are concerned about heating, cut a strip of thin aluminium the same width of the insulation and about 14 inches long. Roll it into a cylinder and push it into the aperture so it expands into place. You could probably do a similar thing with Bacofoil but make sure it can't touch live contacts. There is a vast range of the lights manufactured but few retailers stock anything like all of them. Wattage goes from 5 to 50 but I wouldn't go above 20w on a boat they are just too bright. There is also an option of beam divergence (spot / flood) 10 deg (narrow) up to 45 deg (flood), again few shops bother to stock a good range. One tip. These lights are rated at 12 volts, as you know when the engine is running the volts can reach close to 14 and Tungsten halogen lamps are intollerant of over voltage. Wire you downlights with say 1.0 mm cable to give a little volt-drop the lamps will last a lot longer. These downlights are very clever. originally designed for display lighting some years ago they use a 'diachroic' reflector which allows the red (hot) end of the spectrum to pass right through it. That's why you need to be a little bit carefull about what is behind, but there is not that much energy. John Squeers Edited November 3, 2004 by John Orentas Link to comment Share on other sites More sharing options...
Richard Bustens Posted November 3, 2004 Author Report Share Posted November 3, 2004 Hi John I have done the wiring in 2.5 that gives a volt drop of .5 with 3 20w bulbs How much volt drop do u think i should be aiming for? Link to comment Share on other sites More sharing options...
John Orentas Posted November 3, 2004 Report Share Posted November 3, 2004 Hi Richard. I wouldn't bother Richard, if you find at some stage that you are going through lamps a bit rapidly you can think about putting a resistor in series, it can only be a problem when the lights are on and the engine running. John Squeers Link to comment Share on other sites More sharing options...
Richard Bustens Posted November 3, 2004 Author Report Share Posted November 3, 2004 thanks John By cutting the sprayfome out above the lights it is not going to get condensation dripping on the electrics is it.? Link to comment Share on other sites More sharing options...
John Orentas Posted November 3, 2004 Report Share Posted November 3, 2004 Hi Richard. Really can't see that being a problem but leave a bit in place if there is room. John Squeers Link to comment Share on other sites More sharing options...
stuart Posted November 3, 2004 Report Share Posted November 3, 2004 thanks JohnBy cutting the sprayfome out above the lights it is not going to get condensation dripping on the electrics is it.? <{POST_SNAPBACK}> Hi Richard, I'm also fitting similar lights and wondered how you ran cable to each light, I have a central trunk cable running to 4 downlights (at each corner of a square). Did you just use ducting to each light (to avoid the foam vs PvC problem) or different cable, or even just duct tape over the PVC? Link to comment Share on other sites More sharing options...
John Orentas Posted November 3, 2004 Report Share Posted November 3, 2004 Stuart. The PvC problem applies only to it's use with polystyrene insulation, Richard has had his interior 'Sprayfoamed' so I don't think there is a problem. If you have polystyrene fitted there are several ways around the problem. 1/ I used silicon insulated cable where it contacted the insulation, butyl rubber is another option. 2/ Sleeving can be bought cheaply, or as you say wrap it in duct tape. John Squeers Link to comment Share on other sites More sharing options...
stuart Posted November 3, 2004 Report Share Posted November 3, 2004 Stuart. The PvC problem applies only to it's use with polystyrene insulation, Richard has had his interior 'Sprayfoamed' so I don't think there is a problem. If you have polystyrene fitted there are several ways around the problem. 1/ I used silicon insulated cable where it contacted the insulation, butyl rubber is another option. 2/ Sleeving can be bought cheaply, or as you say wrap it in duct tape. John Squeers <{POST_SNAPBACK}> Of course typical spray foam is polyurethane rather than extruded polystyrene insulation sheets. I agree that cheap flexible sleeving will do the job as long as its not PVC !! Link to comment Share on other sites More sharing options...
Richard Bustens Posted November 3, 2004 Author Report Share Posted November 3, 2004 Hi All Ive covered all angles where it can get contact eventhough it should not matter i have put in sleeving. You can get this from city-electrical 10mtr and 20 ends for £10 Link to comment Share on other sites More sharing options...
Big COL Posted November 3, 2004 Report Share Posted November 3, 2004 Hi Richard Just a little piece of info, that may be of help to you and others. If you find that you have a problem with lamps blowing due to excessive voltage you might find the following helpful. My friend had this problem with his 24volt lighting system, he found that his lamps were only lasting a very short time, due to the fact that his domestic voltage was running at 27volts, which is normal on a new boat with new batteries and connected to a land line through a multi inverter. Originally he was told that he would have to suffer this until his batteries became less efficient. However he discovered that some manufacturers produce lamps for a 27volt supply especially for this reason as they were aware that a problem existed with caravans and boats. I think for 12volts they are rated at 13.5 volts. He changed all his bulbs and the problem was cured. Colin Link to comment Share on other sites More sharing options...
Rick Posted November 3, 2004 Report Share Posted November 3, 2004 I read somewhere that running a boat with an altenator controller can result in excess of 16v going through the 12v cables when the engine is running. That'll give the bulbs something to think about. Richard Link to comment Share on other sites More sharing options...
maffi mushkila Posted November 3, 2004 Report Share Posted November 3, 2004 I read somewhere that running a boat with an altenator controller can result in excess of 16v going through the 12v cables when the engine is running.That'll give the bulbs something to think about. Richard Only if the lights are on. Link to comment Share on other sites More sharing options...
Richard Bustens Posted November 3, 2004 Author Report Share Posted November 3, 2004 ive found a DC-DC converter 20-30 volts in and 24volt out with this i can run all the lighting circuits. The other point is i dont think i will have the lights on with the engine running very often. And as yet i have not ruled out the led ones as the manufacture says he has a d/barge and uses them on that he also says i can wire 2 together and use 24v and will need 10 in a room 13' x 6' that means all 10 in the lounge will take 10w in stead of the 120 i will use with conventional ones Ime getting 2 to try to see what light they through out Link to comment Share on other sites More sharing options...
John Orentas Posted November 4, 2004 Report Share Posted November 4, 2004 Hi Rishard. The d/c to d/c converter, are you sure it will supply enough current for all your lighting ? It will need to be quite a few amps output to cover the worst case. John Squeers. Link to comment Share on other sites More sharing options...
Richard Bustens Posted November 4, 2004 Author Report Share Posted November 4, 2004 Hi John No at this time im'e not sure but ime waiting for a eail from USA. I also wondered about putting a regulator from a old altornator in the circuit that should carry the current. Link to comment Share on other sites More sharing options...
Rick Posted November 4, 2004 Report Share Posted November 4, 2004 Only if the lights are on. <{POST_SNAPBACK}> Sorry, took that as understood. If the lights aren't on then nothing is going through the cables. Richard Link to comment Share on other sites More sharing options...
Rick Posted November 4, 2004 Report Share Posted November 4, 2004 (edited) (The other point is i dont think i will have the lights on with the engine running very often.) I would agree, I don't think I will have them on with the engine running very often. However, I don't know about you but if I have the opportunity to cock something up I seize it with both hands, eventually. Richard Edited November 4, 2004 by Rick Link to comment Share on other sites More sharing options...
Richard Bustens Posted November 4, 2004 Author Report Share Posted November 4, 2004 EVENTUALLY!! arnt you the lucky one i usualy manage to do it from the begining. Link to comment Share on other sites More sharing options...
rustyduck Posted November 5, 2004 Report Share Posted November 5, 2004 Your only saying that Richard so I don't feel left out! Link to comment Share on other sites More sharing options...
Clive A Posted January 27, 2005 Report Share Posted January 27, 2005 Hi all How do you fit the downlighters in the roof, they say they need 4'' clearance, that is not a problem in itself but do i remove the insulation above them. And what whattage bulbs do you use.? <{POST_SNAPBACK}> I was talking to an electrician on site about 12V downlighters, and about the 4" clearance, he warned me not to fit them as you shouldn't insulate between them! If they're household bulbs, they are designed to recess into a ceiling, where there will be sufficient airflow around the back of the bulb. Any insulation will hamper this flow, causing the bulb to keep blowing. And the thought of you just cutting a small hole into the sprayfoam is making me cringe with possible fire hazards. It might be possible to source different bulbs that'd work, not sure. I've decided to use 12V kitchen downlighters that are designed to fit under wall cabinets. They come in their own casing(so designed not to get hot) that is surface mounted - seen some stainless steel triangular ones! Clive Link to comment Share on other sites More sharing options...
Richard Bustens Posted January 27, 2005 Author Report Share Posted January 27, 2005 Hi Clive They are the same kind if bulbs, but don't forget we will be using 10 or 20 W bulbs. not the 50 W ones you see in houses Link to comment Share on other sites More sharing options...
Clive A Posted January 28, 2005 Report Share Posted January 28, 2005 I keep forgetting this is my first fit-out, I'm used to fitting out houses! I'm still sure that the bulbs will need rear ventilation (oo-er missus), isn't that what the 4" is all about (done it again!) ? The downlighters I mentioned go up to 60W, so less bulbs needed, I thought. Link to comment Share on other sites More sharing options...
maffi mushkila Posted January 28, 2005 Report Share Posted January 28, 2005 Hi Clive They are the same kind if bulbs, but don't forget we will be using 10 or 20 W bulbs. not the 50 W ones you see in houses <{POST_SNAPBACK}> Richard, try holding a 20 w lamp that has been on for a while you might be in for a surprise! Link to comment Share on other sites More sharing options...
John Orentas Posted January 28, 2005 Report Share Posted January 28, 2005 (edited) Clive. 20 watt tungsten halogen down lighters are as much as you will ever need on a boat but don't totally ignore the rear space issue, as I have mentioned before the reflectors on these fittings are invariably diachronic, which means the red (hot) end of the spectrum passes through to the area behind. You will need less light generally on a boat, low ceilings etc. Inverse square law and all that. Edited January 28, 2005 by John Orentas Link to comment Share on other sites More sharing options...
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