24V wheel house light fire

[Richo1]

:o

Hi All,

Have spent 20years working at sea now and just experienced my first fire onboard.
Turned out only to be a minor incident, however we were lucky someone was on the bridge at the time to raise the alarm.

The reason I'm posting this here is that some of you may have the same or a similar light on your boats.

It had only been running for about 10minutes on a 24volt system when it literally exploded and caught fire. Fire was put out quickly with a CO2 extinguisher. Unfortunately I don't have the make or model number as yet but it was a Halogen bulb set up, rated for 12 to 24volt power supply. Electrical system has been checked and found ok so it was a fault in the light itself. The light was fitted new in January so not even 6months old. Will be replacing it with an LED light this time.

Cheers

Richo

[Richo1]

https://www.12volt.com.au/General%20Htmls/webcat2003/catalogue%20work%20in%20progrHE44.JPG
Used to look like this except chrome.

[tropicrows]

You can never be to careful, those Halogen lights get really hot. Thanks for letting us know, I dont particularly like the actual LED light emitted but thay sure appear to be safer.

[purnong]

That's not very good mate, I know 24v doesn't muck around when it shorts but it begs the question was that circuit fused?
It should have blown the fuse before it got to the catching fire stage but then again as I said 24v is a totally different animal to 12v

[The-easyrider]

I attended to a boat that burnt to the water line over at Moreton a few years back due to a cheap 12 volt fluro that was left on and unatended.

[Richo1]

It was hooked up to a circuit breaker and switchboard, the mate turned the light off at the switch on the unit while it was burining. It seems that the light got that hot that it blew and caught fire with the light bulb still glowing. Wiring attached to the light was still intact circuit breaker never tripped.

[purnong]

It was hooked up to a circuit breaker and switchboard, the mate turned the light off at the switch on the unit while it was burining. It seems that the light got that hot that it blew and caught fire with the light bulb still glowing. Wiring attached to the light was still intact circuit breaker never tripped.

Ahh O'k, So the light fitting itself got too hot and melted and caught fire, Shit that's a worry isn't it?

Not meaning to take this thread off topic but I have a real concern when I see cheapy 12/24v circuit breakers used such as the one in the pic below, They just do not work
I tested one direct to a 120AH battery and the wires melted and it didn't even look like tripping, They Might be O'k for heavy current draw but they definitely will not trip on a short

http://i277.photobucket.com/albums/kk52/purnong_2008/CircuitBreaker.jpg

[Giffo65]

Have you blokes that overnight on your boats, thought about smoke alarms in the sleeping quarters,they are are a cheap life saver.

[Midnight]

Couple of good points here,

Halogen lights bad.

CO2 fire extinguishers good, and they don't make a mess.

Giffo, yep got a smoke detector and carbon monoxide detector also, for when running the genset overnight for the aircon.

Cheers,
Myles

[Spaniard_King]

I would not put total faith in LED lights either, I have had 2 yep 2 LED nav lights burn out/ actually go up in flames whilst traveling at night.

The first was 40klm out of 1770, we started to smell burning, a decky pointed out we were a little to far out for a land smell... stopped the boat and shut everything down untill we located it... no fuse (10 amp) blown either.. same deal for both times. Second time we new straight away what it was.... scary tho

[purnong]

I would not put total faith in LED lights either, I have had 2 yep 2 LED nav lights burn out/ actually go up in flames whilst traveling at night.

The first was 40klm out of 1770, we started to smell burning, a decky pointed out we were a little to far out for a land smell... stopped the boat and shut everything down untill we located it... no fuse (10 amp) blown either.. same deal for both times. Second time we new straight away what it was.... scary tho

Actually that's a good point Spaniard King, I wonder if because the LED lights have such low current draw if a 10 amp fuse is too large, Maybe a smaller fuse to suit the current draw would be better
I'm only thinking out loud here but it seems to make sense

[Spaniard_King]

The fuse in this case is there to protect the wiring not the lights.

The way they went up I am not sure how smaller fuse would be needed to stop it.

[purnong]

The fuse in this case is there to protect the wiring not the lights.

The way they went up I am not sure how smaller fuse would be needed to stop it.

Yep fair enough mate, I was sort of thinking along the lines of that because Led circuits and wiring are built so light on that they would fuse and burn out before a 10 amp fuse would blow
Like I said, Just thinking out loud, I have no qualifications in this area so I am only surmising
Interesting discussion though

[TheRealAndy]

Just remember, a fuse/circuit breaker will not fail at its rated current. A 10Amp fuse is designed to to handle a 10amp load. It may not blow till 20amps is flowing through it. Fuses are rated to blow with a certain amount of energy. There is a lot of variables. A fuse can operate just above it rated current and not blow for hours, but it may blow in one minute if its a few amps above its rated current. Temperature will also affect the time it takes for a fuse to blow.

[purnong]

Just remember, a fuse/circuit breaker will not fail at its rated current. A 10Amp fuse is designed to to handle a 10amp load. It may not blow till 20amps is flowing through it. Fuses are rated to blow with a certain amount of energy. There is a lot of variables. A fuse can operate just above it rated current and not blow for hours, but it may blow in one minute if its a few amps above its rated current. Temperature will also affect the time it takes for a fuse to blow.

Thanks Andy, So that applies with current draw but where does it sit with a dead short, I presume a dead short above the rating of the fuse would blow unless the wiring is below the rating of the fuse wherein the wiring/fitting would burn before the fuse blows
Does that make sense?

[TheRealAndy]

Thanks Andy, So that applies with current draw but where does it sit with a dead short, I presume a dead short above the rating of the fuse would blow unless the wiring is below the rating of the fuse wherein the wiring/fitting would burn before the fuse blows
Does that make sense?

Yup, that makes sense.

A dead short is drawing current from a battery. If your dead short is spanner, then its going to draw a lot of current. If your dead short is piece of steel wool then it little current.

Do this as an experiment if you wish. Get a 1 amp fuse and some steel wool. Short out the steel wool after the fuse. The steel wool will catch on fire, even though the circuit is fused.

[purnong]

Yup, that makes sense.

A dead short is drawing current from a battery. If your dead short is spanner, then its going to draw a lot of current. If your dead short is piece of steel wool then it little current.

Do this as an experiment if you wish. Get a 1 amp fuse and some steel wool. Short out the steel wool after the fuse. The steel wool will catch on fire, even though the circuit is fused.

Thanks Andy
So going by your above example would it be wise for those of us using LED lights to run a very low amp fuse to protect the wiring/circuit?
I guess if your LED circuit draws 1 amp for example you would not want a much larger fuse than that to protect the circuit/Wiring
The LED's in my boat are on a 10 amp fuse but after thinking about this I might swap the fuse over to something lower

[TheRealAndy]

Thanks Andy
So going by your above example would it be wise for those of us using LED lights to run a very low amp fuse to protect the wiring/circuit?
I guess if your LED circuit draws 1 amp for example you would not want a much larger fuse than that to protect the circuit/Wiring
The LED's in my boat are on a 10 amp fuse but after thinking about this I might swap the fuse over to something lower

You are not likely to have many issues with LED lights. I always prefer to err on the side of caution though and use the smallest fuse possible.

[cormorant]

G'day

Here is my guess.

A lot of fittings say they are rated 12v -24v and the fitting and wires are but then the catch - what globe was in it ? - the one that came with it rated for 12v that will generate 5 times the heat at 24v or did someone buy and fit a 24v globe?

In the old days a lot of stuff had themal fuses at the fitting so if you got red hot they would stop suplying the current.

Spaniard K I'd be pretty worried about a burning nav light. Were they faulty or not coping with 14v and just overheating? . I tried a couple of early cheap nav lights and they an really hot - hella don't but the wallet hurts for months.

Amazing how sensiive you get to the smell of smoke or plastic electrical smell when out wide or moored. Moored up one night kept waking up and smelling electrical insulation smell- sent me absolutely nuts, couldn't find it , every breaker off, Checked winch, battery switch off , carefully lifted cowls, even opened the compartments in case it was one of the bilge pumps melting but not throwing the fuse then in frustration pulled the plugs from the solar panels ( at night laughable) . After a several times waking and sleeping on deck with a bucket of water I finally worked it out that 2 blokes moored 100m away were making up rigs and melting shrinkwrap with a lighter. Could have murdered them. Slept through the dawn tide- not happy. Found a couple of possible future problems though.

[Richo1]

It was fitted by a shoreside technician, but I reckon you may be right with it having the wrong bulb in it! Technician was pretty keen to take the old burnt out light with him, maybe to hide the evidence ;)

[trymyluck]

I would not put total faith in LED lights either, I have had 2 yep 2 LED nav lights burn out/ actually go up in flames whilst traveling at night.

The first was 40klm out of 1770, we started to smell burning, a decky pointed out we were a little to far out for a land smell... stopped the boat and shut everything down untill we located it... no fuse (10 amp) blown either.. same deal for both times. Second time we new straight away what it was.... scary tho


The fuse in this case is there to protect the wiring not the lights.

The way they went up I am not sure how smaller fuse would be needed to stop it.


You are not likely to have many issues with LED lights. I always prefer to err on the side of caution though and use the smallest fuse possible.


Andy, I would say that the above quote would be an indication that there may be a major issue with led lights..... Most electronics have fuses way below the rating of the wire, maybe this should be the way to go. ::)

Gary, did you happen to report this to the supplier or manufacturer, maybe they should be supplied with a maximum fuse rating.

I'm thinking that I may run the set I have to go on the boat over night on a spare battery and see how hot they get before I fit them.......:-?


Mark

[TheRealAndy]

Here is a tip. look for the UL stamp on the device, http://www.ul.com/global/eng/pages/corporate/aboutul/ulmarks/mark/ if compliant, the device wont catch on fire if faulty.

Plus. ifts UL approved, it cost money to get there. Chances are its fairly decent product.

[ozbee]

i had a led light catch on fire on a trip woke up to that burning smell. it was one of those rectangular ones that hold 48 leds about half of them burnt black before she lit up . i am very wary of them