Equipment

[TC5]

Hi

 

I am considering various options for lighting my yet to be built narrow boat. I favour the use of small flourescent tubes behind pelmets, I am also thinking of down lighters. The quartz halogen variety provide excellent light but I have concerns about heat disipation within the confines of the roof. Does anyone have experience of this type of light and does it discolour the wood with time? I have been doing research into LED's with some success but find that the light spread is very narrow. The great advantage of LED's is next to no power consumption and no heat generation.

 

Cheers

 

TC

[John Orentas]

Hi TC.

 

Fluorescent lighting is still the most efficient type of lighting and much the best for area lighting. The idea of tubes behind the pelmets is a very good one (not least because I have done just that). Go for the PL (COMPACT) types, 18 watt is very good but try to find good quality electronic ballasts. A prismatic diffuser in front of the lamp gives an improvement.

 

Tungsten halogen down lighters are ok for feature lighting, 20 watts are as bright as you need and you won't have any temp. problems with them but it you go higher fit a strip of thin aluminium cylinder inside the ceiling aperture. If you use down lighters, under wire them to reduce the voltage a bit.

 

LED's can be ok for certain things but they gain their efficiency by cleverly focused optics which aren't much good for general lighting.

 

If you go with plan 'A' don't buy complete fittings, I can help you obtain them in component form.

Edited March 31, 2005 by John Orentas

[nbtafelberg]

Actually

 

COMPRESSED flurescent is the best. I use 7 watt lights which I sell - have a look at www.lightupyourboat.com .

 

I agree about LED's though, I have an LED spotlight - it was very expensive and pretty useless.

[DHutch]

Yeah, i did a little resercg about LEDs, there not as impressive as there made out to be, especially not the white ones, which are bearly better than you average halogen.

- The more effecent as sayed about are presurised flurecents.

 

 

Daniel

[timboharticus]

 

There are now some fluorescent GU10 downlighters available.

 

"Megaman" are the manufacturer.

[DHutch]

They look, well done timbo!

 

linky to there site, if you interested - and another linky

 

Megaman's new 7w and 9w CFL GU10 reflector lamps in most cases offer a direct low energy replacement to the GU10 halogen lamp.

 

Representing the second generation of GU10 compact fluorescent lamps the new models incorporate the company's exclusive Ingenium technology, which delivers breakthrough lighting performance and superior operating life expectancy of 15,000 hours, combined with improved life cycle switching and a shorter preheating time. In addition, the integral cooling tube keeps operating temperatures to a minimum for enhanced safety.

 

The components used in this new technology are extremely small, which has resulted in the physical size of the lamp being reduced accordingly. The new 7w GU10 is 10mm shorter than its predecessor. This allows GU10 halogen lamps to be simply and quickly replaced by compact fluorescent, providing substantial energy savings, longer life and lower maintenance costs.

 

The new 9w gives an increased luminous efficacy for applications where a higher light output is required.

 

In using a compact fluorescent light source, CFL GU10 lamps provide an operating life some 7 and a half times longer than halogen GU10, with up to 80% energy savings.

 

They sound good, might get some to try out in our kitchen (and there good, i might look as puting som in the boat.)

 

Thanks again tim, Daniel

[DHutch]

Also, Ricam seam to have made one was well

 

And somwhere selling them in the here for £10 a throw. (only other place if found has them for AU$ 7.90

 

Daniel

[Hondaman]

Tungsten halogen down lighters are ok for feature lighting, 20 watts are as bright as you need and you won't have any temp. problems with them but it you go higher fit a strip of thin aluminium cylinder inside the ceiling aperture.  If you use down lighters, under wire them to reduce the voltage a bit.

 

<{POST_SNAPBACK}>

 

Totally agree about flourescents for areas. The halogen downlighters don't have much spread and don't give so much light for 20w as a 16w twin tube (taking 20w).

 

There are usually fitting instructions with downlighters giving minimum clearance/ventilation area. While the steel roof is not a fire hazard, the wire is and should be kept well to the side of the lights unless of high temp insulation, especially with the good thermal insulation around the lamp above the ceiling panel.

 

Clearance above the ceiling for the terminals can be a problem onsome boats especially with the swivel type lamps, which take more depth.

 

Not too happy about under wiring, all the wire on a circuit should be capable of taking the fuse/trip current, and that means the current that would be drawn with all the lights on. If only a few are in use there should be hardly any voltage drop.

[DHutch]

Not too happy about under wiring, all the wire on a circuit should be capable of taking the fuse/trip current.

 

No, i dont think i would be eather. All our wiring was tested (Shorting the end breifly to make sure the MCB triped)

 

- If you wish to lower/regulate the voltage to 12v for the light i would use a soild-state voltage regulator. They you get a constant 12v what ever voltage the of the batterys is. (as long as there above 10v)

 

 

 

Daniel

[ChrisPy]

Not too happy about under wiring, all the wire on a circuit should be capable of taking the fuse/trip current, and that means the current that would be drawn with all the lights on. If only a few are in use there should be hardly any voltage drop.

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I am just sizing my wiring and I find that in every case the economic size of cable (whose current rating well exceeds the load) still gives significant voltage drops. For example a lighting circuit in 28/0.30 cable rated at 17.5A feeding back through a common negative serves a diversified load of 12A and has a voltage drop of 3.5V.

It certainly puts things into perspective. I will have to go up to 44/0.30 cable in this case, and increase the negative cable size, and will still have significant voltage drop of 2.3V.

[Richard Bustens]

Hi Chris

I have put 2.5 cabling for all my lighting and have run a separate supply for each room/ area with the exception of the lounge where i have run two.

I know i am in 24v but have not exceeded .5v anywhere.

The majority of boatbuilders seem to run two or three 6mm pairs of cables the length of the boat and T off as required with a switch for every 2 lights alternating the cables used.

I did look at doing it this way but opted for separate runs for each area with two way switches on both ends of each room.

Edited April 1, 2005 by Richard Bustens

[stuart]

I've used 6mm2 cable to each lighting circuit (1 per room) then 2.5mm2 cable to each light/switch combination.

 

No problems so far!

[stuart]

Not too happy about under wiring, all the wire on a circuit should be capable of taking the fuse/trip current,

<{POST_SNAPBACK}>

 

I think John was referring to using smaller cable sizes which are still capable of carrying the current required safely - but actually encourage a voltage drop.

 

Some Halogen lights are very sensitive to over voltage, so if your alternator is is pushing out more than 12v (and it will when charging) you can get through lots of bulbs.

 

If you have a voltage drop in the cable, it will probably loose a volt or two, so normally only 10-11v is reached, when the alternator is on, probably 12-13v is achieved.

[Richard Bustens]

I don't think that is a safe way to do things .

Don't forget that in volt loss heat is generated, where as .5 of a volt is acceptable but 2v is not it will generate a lot of heat and something may catch fire.

That is how a electric fire works.

[John Orentas]

Yes when I referred to under wiring I wasn't thinking in terms of multi lamps systems, I have separate supplies to all light switches and only one fitting per switch, in this case you can wire in 1.5mm and get a small beneficial volt drop.

 

You would have to under-rate your wiring to grotesque levels before there is any risk of anything over heating.

 

Anyway when I start writing about under-wired things my concentration wanders to other topics.

[gringogordo]

I have a set of 5 LED spots which are okay. I bought halogens without thinking and they used a lot of power and got very hot. Changed to LED as I had already put the fittings in and the result is better than I expected but not fantastic, just about good enough to read in though. I have been in a marina with power since I got them though so I'm not sure what the consumption is like.

 

Anyway to repeat what most people have probably said already I'd go with flor with a couple of halogen/led specific bulbs for reading/writing spots.

 

Cheers,

 

Ben.

[ChrisPy]

Anyway when I start writing about under-wired things my concentration wanders to other topics.

<{POST_SNAPBACK}>

well I picked it up anyway

[ChrisPy]

I've used 6mm2 cable to each lighting circuit (1 per room) then 2.5mm2 cable  to each light/switch combination.

 

No problems so far!

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........... and according to the rules you would fuse (breaker) that circuit for less than the rating of the smallest cable, i.e. 2.5mm2 ??

[ChrisPy]

I don't think that is a safe way to do things .

Don't forget that in  volt loss heat is generated, where as .5 of a volt is acceptable but 2v is not it will generate a lot of heat and something may catch fire.

That is how a electric fire works.

<{POST_SNAPBACK}>

I'm assuming that, given the cables aren't bundled too tight, etc., the current rating of the cable is the safe limit to avoid overheating. We are talking of 2V drop over perhaps 30m of cable (there and back).

Please correct me if I'm wrong (I often am ).

[Richard Bustens]

2V does not sound a lot but 17-18% does or 400% more than recomended now that sounds a lot.

The max permitted volt drop on 12v is .5v

Edited April 1, 2005 by Richard Bustens

[ChrisPy]

The max permitted volt drop on 12v is .5v

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maximum permitted?? by who??

[NB Willawaw]

Has anybody seen the Osram Decostar 1 ALU halogens which have an aluminium coating on the backside, said to reduce back-heat by about 80% compared to a conventional dichroic reflector.

The light output is only about 1100cd at 35W and 700cd at 20W, but it has a 38 degree beamwidth which should make it ideal for deckhead mounted recessed downlighting.

 

Best Regards

 

Mark

[stuart]

35W and 20W seems quite bright to me.

 

I've used a number of 10W halogen lights spread around the cabin and its perfectly bright enough - probably too bright!

 

Halogen does have a narrow beam of light, so just use more lower powered ones spread evenly over an area.

 

They do require more power than fluroscent lights though.

[Richard Bustens]

maximum permitted??  by who??

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Permitted is probably the wrong word "recomended" is better.

 

I think i got this from a training course at Mastervolt it is in the course notes.

[NB Willawaw]

Stuart,

 

The power rating is the power used, not necessarily directly proportional to the light emitted, hence my point about 700cd at 20W. I think if you look up the spec of your lights, you will find the output of your 10W conventional halogen is a lot higher in candela.

I'm by no means an expert in lighting but I would suggest that this Osram lamp is diffusing the light available by employing a wider beamwidth. Its just a guess, but your light is probably 10W with a smaller beamwidth and higher output in candela.

My main reason for mentioning this model is that the lack of heat being dissipated back into the roof might be an attractive feature since people are talking about overheating problems.

 

Mark

 

 

35W and 20W seems quite bright to me. 

 

I've used a number of 10W halogen lights spread around the cabin and its perfectly bright enough - probably too bright!

 

Halogen does have a narrow beam of light, so just use more lower powered ones spread evenly over an area. 

 

They do require more power than fluroscent lights though.

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