Rewiring a mast for LED's

jonrarit

jonrarit

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I'm rewiring the mast this year with anchor light, deck light and steaming light all being replaced with LED bulbs. The tri-colour remains a standard 25watt bulb and there's plenty of info on the suitable guage wire for that light, but any views suggestions on the right wire for the LED bulbs. I'm led to believe that LEDs can use a much lighter guage?

Jr

Beneteau First 345
 
jonrarit said:
I'm led to believe that LEDs can use a much lighter guage?
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Wire gauge is chosen to reduce voltage drop, so that the voltage actually received by the light is adequate. Higher wattage bulbs at the end of very long lengths of wire can suffer particularly from voltage drop, which is why masthead lights usually have quite chunky wire. But voltage drop is proportional to the current drawn, so low current lights such as LEDs will create less voltage drop and can use thinner wiring. However, there's a compromise to be reached between having thinner wire and having wire which is substantial enough to cope with physical stresses. So, by all means use thinner wire than for the 25W tricolour, but don't go too thin.
 
as above from pvb but if the boat is a long term project/ownership, stretch the budget to use tinned wire to get fewer connection problems.

Don't forget to make the cables weight be well supported at the top of the mast and not just hanging on its connection points.

If you have trunking running up your mast, try to get the cables running up through it. This will mean less flopping about which puts stress on top attachment and the noise can be a pain if the cable is going back and forth all night on a mooring.

I advise that you use an extra big deck gland to run the cables through so that you can pass all your connectors through the hole easily before sealing down and making good the connections inside.

I tried to have very expensive plugs and sockets outside the boat at the mast step and even though supposedly waterproof, 3 of the 7 plugs and sockets got water inside in the first week afloat.

S.
 
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What PVB says.

Check the current draw of your chosen LED units . You will probably find them to be in the range 0.25 to 0.5 amps but there is a big variation.

That range means in theory you could use wire 1/4 to 1/8 the crossectional area of that required for a conventional bulb. Not only that but the electronic circuitry means they are tolerant of a much greater voltage drop. Possibly operating down to 10 volts.
End result is that you could in theory get away with ridiculously thin wire.

As PVB says stick with wire that is adequately robust. 1.0mm2 minimum perhaps.


Odd that you are not considering changing the tricolour bulb. That and the anchor light are the ones most likely to be in use when the engine is not providing the power and I would have thought one of the prime candidates for swapping to LED...... The tricolour lamp is the only one I have swapped on my boat.
 
VicMallows said:
Changing the tri-colour to LED? As you say, not cheap or particularly easy, but possibly worthwhile. I would be worrying if I could not remember :D:D
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Largest part of £30 IIRC for the three coloured LED unit for the tricolour when I bought mine. Now nearly £50 from Force4 **

Bit of a fiddle to fit because it came with a new holder which had to be positioned correctly so that the coloured LEDS lined up with the respective coloured lenses. Would be difficult with the mast standing. **

Had to start by powering up the LED and marking the front as all the leds looked the same when off.

Old holder:

DSCF0957.jpg



LED and new holder:

DSCF0956.jpg



Using an all white LED unit possible but not entirely satisfactory because a warm white is necessary for the red and green sectors but cold white is better for the white sector.

Loadsa info and advice on the Boatlamps website.

** Just under £40 from Boatlamps who can supply the correct unit without needing to change the holder! I dont think they did them when I bought mine.
 
I changed my anchor and tricolour (engine not running) lamps to LEDs and my steaming, stern and sidelights I left as amp hungry incandescents( engine running)

Seemed to make sense to me
 
As said lighter wire for LED's would be OK. However ina harsh environment larger wire seems to last longer when you think of corrosion or physical damage so I would stick with fairly robust wire. good luck olewill
 
VicS said:
What PVB says.
Odd that you are not considering changing the tricolour bulb. That and the anchor light are the ones most likely to be in use when the engine is not providing the power and I would have thought one of the prime candidates for swapping to LED...... The tricolour lamp is the only one I have swapped on my boat.
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I also left my tricolur as tungsten as I have several spare nav light bulbs on board, just changed the anchor light to LED which is a straight plug-in.

Looking at the cost which is the criteria for many people, an extra battery can be installed for the same price as changing to LED + a spare bulb and is a far more effective solution when also looking at other power hungry sailing items such as radar and autopilot.
 
GrahamM376 said:
I also left my tricolur as tungsten as I have several spare nav light bulbs on board, just changed the anchor light to LED which is a straight plug-in.

Looking at the cost which is the criteria for many people, an extra battery can be installed for the same price as changing to LED + a spare bulb and is a far more effective solution when also looking at other power hungry sailing items such as radar and autopilot.
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It won't help you sleep at night though! I changed every bulb other than the steaming light to LED and now I can leave them all running for a week without having to worry about it. There are enough things to worry about on a boat without worrying that someone has left a light on which will kill your extra new battery.
 
pmagowan said:
It won't help you sleep at night though! I changed every bulb other than the steaming light to LED and now I can leave them all running for a week without having to worry about it. There are enough things to worry about on a boat without worrying that someone has left a light on which will kill your extra new battery.
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+1

One of my pet hates is to be distracted by low battery volts and I really detest motoring.

My solar panel charge has just stopped getting to the regulator so I need to check/rewire.

That really is a pain if it's not windy enough to liven up my wind generator..... not a lot of fear of that this week though
http://www.xcweather.co.uk/forecast/portsmouth

:)

S.
 
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pmagowan said:
I sized my wiring for incandescent but used LEDs for everything bar the steaming light. My thoughts were that someone may put a different bulb in in the future.
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When you actually work out the length of run for masthead lights on a medium-sized boat, the wire needed for acceptable volt-drop on a 25w incandescent really is quite large. It wouldn't have all fitted in the duct on my mast. Since I also removed the bulb holders and soldered the LED lamps to the end of the supply cable, I don't think anybody's going to be popping in one of those Victorian heating coils any time soon :)

(In any case, the diode network that selects the different light combinations from a single rotary knob was designed with LED currents in mind. It may work for white-hot energy-wasters but I wouldn't bet on it.)

I'm also committed to LEDs internally, because I have a single "Cabin Lights" fused circuit. I suspect if I added up the potential total draw of tungsten or halogen in every light fitting, the required fuse would be so large that it wouldn't adequately protect the wire size used. I assume that's why boats often used to have a pair of lighting circuits.

Pete
 
pmagowan said:
It won't help you sleep at night though! I changed every bulb other than the steaming light to LED and now I can leave them all running for a week without having to worry about it. There are enough things to worry about on a boat without worrying that someone has left a light on which will kill your extra new battery.
Click to expand...

I sleep well enough at night and can last indefinately with LED anchor and below-deck lights, large battery banks + solar + wind genny. Fridge running 24/7 + computer, TV etc. In reality, a minority of boats sail at night and if someone with marginal battery reserve can't check their lights are off then they deserve to have flat batteries.
 
GrahamM376 said:
I sleep well enough at night and can last indefinately with LED anchor and below-deck lights, large battery banks + solar + wind genny. Fridge running 24/7 + computer, TV etc. In reality, a minority of boats sail at night and if someone with marginal battery reserve can't check their lights are off then they deserve to have flat batteries.
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Yes I'm one of those who deserved flat service batteries having forgotten to switch off the non led nav' lights years ago after anchoring up.

It's a bitter pill to swallow when you have to run the batteries up for an hour next morning, to enable all systems can be switched on.

I'm interested to know what size and type of battery bank you have.


S.
 
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Thanks for the replies, I'll just go like for like then when I renew. The reason I was going to leave the masthead is that I read somewhere LED bulbs don't work well when shining through the coloured lens of the tricolour.

jr
 
jonrarit said:
Thanks for the replies, I'll just go like for like then when I renew. The reason I was going to leave the masthead is that I read somewhere LED bulbs don't work well when shining through the coloured lens of the tricolour.

jr
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I believe there are types of LED bulb that now meet the required criteria for not returning the colour to white when seen through a red or green lens.

Can others confirm?

S.
 
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