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Topic Title: Marine LED lighting.
Topic Summary: Has anyone any experience of battery/inverter/charger power for LED's?
Created On: 02 November 2012 11:43 AM
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 02 November 2012 11:43 AM
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cmatheson

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I have been asked to help in the wiring of a new 10 cabin canal cruiser. The client has this week informed me that he has decided to use 24v dc LED lighting and that he need to start buying wire and, next week, to have the joiners start with lining the ceilings - so no pressure!

He has asked an experienced marine electrician to try to optimise wire costs and he has come up with a distribution plan that involves wiring all final lighting circuits in 2.5mm marine flex. I noted he has costed th lights at about £2.50 per fitting and £2.50 per LED lamp.

From what research I have been able to do it appears to me that powering these lights wil not be simple:

It appears that:

1. The 24v power supply will vary significantly as batteries deplete and as charging occurs, as well as large transients from dc pumps etc potentially destroying the LED's.

2. LED's (?generally) require constant current. Some LED lamps are sold as constant voltage devices and include resistors which, in dissipating energy as heat, sigificantly reduce the energy efficiency

3. A dc to dc converter is therefore required to provide constant current to the (string of) led's as well as for transient suppression.

4. Some converters are very noisy and may affect the nav and radio.

5. Fittings supplied with (non-replaceable) led's include dc converters or part of the above.

I feel it would make sense to have a single transient suppression system for the entire boat and asked the marine electrician if they use such a device but it seems that that is provided by 24v to 12v power supply for their gear.

Also, it seems to me that it would make sense to not have a dc converter for every lamp but one for each circuit, but will will that give me the variability of current required to go from minimum to maximum lighting?

How am I doing so far?

My thinking at the moment is that it will probably make most sense to buy fittings with led's from one of the leading marine suppliers but the likelihood of being able to get these for £5 each is slim.

-------------------------
Chris Matheson MInstMC
 02 November 2012 07:30 PM
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weirdbeard

Posts: 1619
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Originally posted by: cmatheson

I have been asked to help in the wiring of a new 10 cabin canal cruiser. The client has this week informed me that he has decided to use 24v dc LED lighting and that he need to start buying wire and, next week, to have the joiners start with lining the ceilings - so no pressure!



Hi chris, I have very few areas of expertise, and this isn't one of them!

Though I did find an LED lighting website that says they also have 30 years experience with canal boats - might be worth giving them a ring?

http://www.bedazzled.uk.com/




He has asked an experienced marine electrician to try to optimise wire costs and he has come up with a distribution plan that involves wiring all final lighting circuits in 2.5mm marine flex. I noted he has costed th lights at about £2.50 per fitting and £2.50 per LED lamp.



the likelihood of being able to get these for £5 each is slim.


I agree it does sound a bit on the lean side! Out of interest How many watts + fittings are there per cabin?

I recently did a job involving using LED tape and was impressed by its output and controllabilty - if I was having a barge done myself I think it would be ideal for the lighting, though would probably cost a bit more than £5 per room!
 02 November 2012 08:27 PM
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cmatheson

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Thanks, I agree that would be a goood place to start.

Buget for lighting was 120W per cabin based on 230vac. I think about a quarter of that should give all the light required using leds.

I have been looking at the tapes with interest. I think a bit of imaginative joinery and the space would be well lit and look great!

-------------------------
Chris Matheson MInstMC
 04 November 2012 10:06 AM
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jumpinjax

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What we used to do on boats years ago was run a 230v tv on an inverter as the picture quality, if you could call it that, was far better than running on 12/24v. Why not do the same with the lights? Run an inverter with constant sine wave using 230v led lights, most inverters go into sleep mode when not in use these days.
 04 November 2012 11:08 AM
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cmatheson

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Certainly easier with an inverter but the problem is the losses in the inverter. Also if led lamps are to be used, then the ac supply to those will have to be converted - so more losses.

The intention is to run the engines to travel during the day, then park up and run off battery power until after breakfast.

-------------------------
Chris Matheson MInstMC
 08 November 2012 03:51 PM
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normcall

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The guy at bedazzeled (on the canal near Milton Keynes) is very helpful and can talk you through any problems.

Our new caravan is all LED lighting and although 12v, we do go for several days watching TV etc. without mains electricity and just a couple of solar panels to top the battery up although we have a generator just in case the voltage goes below 11.5v. So far in this wonderful summer, it's not been used as everything seems to work OK. I admit the LEDs have been known to flicker when the water pump (100w) is used for a couple of showers, but touch MDF, so far so good.

-------------------------
Norman
 08 November 2012 04:32 PM
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rocknroll

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I spent a month on a boat that had a mixture of LED's and G4 lighting, the LED's were mainly navigation, under galley cupboards and the en-suites, everywhere else it was G4's even in the wheelhouse, the lights were marine grade (arm and a leg jobby) they were fed from the 24v volt panel through 2 x 12/24v 70W voltage stabilisers (one for each hull), the LED's had built in drivers, for three days and nights being thrown around the ocean every time one of the pumps came on there was a slight dip but only slight, most of the radios and navigation aids such as radar, map plotters etc, have built in stabilisation.

I am a bit confused here as it seems these boats are plodding up and down the river (fresh water) where you are unlikely to be battered by 10ft salty waves and spray why go to the expense of marine grade lights when in that environment standard LED's will suffice.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 09 November 2012 11:45 AM
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BigRed

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Leds are good for this kind of use , just watch out for cheap ones, the CRI is crap on them. Played with some better ones on my friends boat, we used some constant currant drivers from rapid electronics, totally sealed, up to 24 v in, will drive a 350mA Cree led or 4 no problem!
 13 November 2012 11:55 AM
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cmatheson

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The plan is to also have 240vac sockets in the passenger accomodation.

Would I be right to assume that the method of fault protection would be EEBADS for both AC and 24Vdc circuits?

I know that earthing of the boat as a whole is a complex subject, but in regard to special locations within the boat, would there be a need for supplementary earth connections? There will be shower cubicles within the cabins with 24v lighting but no ac within the cubicle itself.

-------------------------
Chris Matheson MInstMC
 13 November 2012 12:13 PM
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rocknroll

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Try and get yourself copies of:

BS EN 10133:2000 - ELV electrical installation in small craft.

BS EN 13297:2000 - AC electrical installation in small craft.

British Marine Federation; 'Code of Practice for Electrical Installations in small craft'.

NB: The Federation used to supply a CD and manual that also included interpretation of BS EN 10133 and BS EN 13297.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------
 13 November 2012 12:13 PM
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AJJewsbury

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Would I be right to assume that the method of fault protection would be EEBADS for both AC and 24Vdc circuits?

Wouldn't 24V d.c. be more likely to be SELV or PELV?
- Andy.
 13 November 2012 08:37 PM
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weirdbeard

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Originally posted by: AJJewsbury



Wouldn't 24V d.c. be more likely to be SELV or PELV?


Hi Andy, I'd have thought SELV or PELV only apply where the supply is derived from mains voltage by a transformer, if the supply is a 24V battery, wouldn't it just be classed as ELV?
 13 November 2012 08:43 PM
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weirdbeard

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Originally posted by: cmatheson

The plan is to also have 240vac sockets in the passenger accomodation.


.


You did mention that you were concerned about inverter losses for the lighting , but if you are having mains to the cabins which will need to be through an inverter then you might as well go with mains powered lights aswell. - I would say 10Watts of well placed LED strip lights per cabin would give more than enough light.
 13 November 2012 10:15 PM
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AJJewsbury

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Hi Andy, I'd have thought SELV or PELV only apply where the supply is derived from mains voltage by a transformer, if the supply is a 24V battery, wouldn't it just be classed as ELV?

I thought that as long as the supply was sufficiently separated from dangerous voltages, then any form of supply would do.

414.3 seems to list (as well as transformers), motor-generators, batteries and diesel-generators as examples of acceptable sources.

- Andy.
 14 November 2012 01:57 PM
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rocknroll

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You really need to take off your domestic hat and procure the documents I have referred to especially when it comes to 230v ac on a small craft, how is the supply derived, does it come from a TN-S supply (most marinas have this) or through an isolating transformer or through the galvanic isolator, even ELV may require earthing.

The problem you have here is that MCB's and RCD's dont fair very well if the conditions are not met and it is not uncommon to have an earth fault without the people on board knowing about it and no CPD devices operating (have experienced this), this only comes to light when nearby craft are affected or when some idiot decides to ignore the marina 'no swimming' policy and jumps in.

On the third day of our peril whilst battling what seemed like a tsunami the earth fault light came on at the console and nothing tripped, it was unpractical to start lifting hatches so we tended to use a pen on any metal switches to be safe, anyway the fourth day sitting on a millpond with no wind we investigated the problem, one of the engines on mountings had travelled further than usual in the storm and ripped the braid out of the terminal, once we replaced this the trip went and the culprit was the coffee machine that had also shifted and ripped the cable in the plug.

As these are river leisure craft with I presume steel hulls and will mostly be parked up and plugged into a supply they will be far more dangerous than sailing yachts so perhaps you need to seek more advice from the professionals in this field.

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------

Edited: 14 November 2012 at 04:24 PM by rocknroll
 15 November 2012 02:26 PM
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cmatheson

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Many thanks Rocknroll, I have seen the Federation document but it doesn't help much. The guide will be useful, thanks, and will try to flush out copies of BS EN 10133:2000 - ELV electrical installation in small craft and BS EN 13297:2000 - AC electrical installation in small craft.

I have talked to a very helpful gent at Bedazzled who advised that the boat safety inspectors currently require that account be taken of the possibility that a future owner may decide to replace his led's with 240v fittings and reconnect his 24vdc light circuit to the 240va inverter output. A good dc/dc converter/driver at the fitting will have high impedance and can drive the requisite current over a wide range of supply voltages so, in theory, CAT5 could be used, but for now we should wire as if for 240v so it looks like 1.0mm 3-core minimum.

-------------------------
Chris Matheson MInstMC
 15 November 2012 03:20 PM
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rocknroll

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No worries.

but for now we should wire as if for 240v so it looks like 1.0mm 3-core minimum.


That is correct, you will find some cable looks like T&E but it is black and the conductors are not bare copper but are tinned for better corrosion resistance.

Gather as much information as you can because boats and 230v is damn dangerous, I have seen a few RYC beasts where the installations have left a lot to be desired, not said anything though as it might affect my final marks. LOL

regards

-------------------------
"Take nothing but a picture,
leave nothing but footprints!"
-------------------------
"Oh! The drama of it all."
-------------------------
"You can throw all the philosophy you like at the problem, but at the end of the day it's just basic electrical theory!"
-------------------------

Edited: 15 November 2012 at 03:37 PM by rocknroll
 15 November 2012 06:58 PM
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Pando

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Originally posted by: cmatheson



4. Some converters are very noisy and may affect the nav and radio.

Just curious, NAV? Surely you can only go forwards or backwards?

As BigRed said, use constant current drivers supplying several LED's up to it's max rating, they are very efficient. Sometimes called buck converters.
 16 November 2012 08:01 AM
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cmatheson

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Originally posted by: Pando


Just curious, NAV? Surely you can only go forwards or backwards?




Caledonian Canal - includes Loch Ness.

-------------------------
Chris Matheson MInstMC
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