A Note about switching to LED lighting...

kalik282 · 04-15-2011, 08:08 PM

I have seen many threads about switching from incandescent lighting to LED lighting. Lots of benefits, not the least of which is less amp draw on the batteries/converter.

However, I have not seen anyone address the issue of safety. Namely, checking the 12V lighting circuit AFTER changing to LEDs and replacing the circuit fuse with an appropriate amp fuse for the new lower draw. Continuing to use the stock, incandescent rated, fuse can lead to a serious fire hazard.

If you are unsure of how to do an amp draw test on your lighting circuits, I suggest you enlist the help of someone that does.

Happy Camping!

John

wfmdfm · 04-15-2011, 08:35 PM

The fuses are there to protect your circuits from over current draw. You can have a circuit with zero load up to full load without issue. Once you get beyond the rated capacity of the conductors and devices on the circuit a fuse or breaker should trip and prevent any damage. Reducing the load on a circuit does not warrant changing the fuse that protects from a overload condition. I don,t see any safety concern with reducing the load but I think your batteries will be very happy.

kalik282 · 04-15-2011, 08:47 PM

Quote:

Originally Posted by wfmdfm

The fuses are there to protect your circuits from over current draw. You can have a circuit with zero load up to full load without issue. Once you get beyond the rated capacity of the conductors and devices on the circuit a fuse or breaker should trip and prevent any damage. Reducing the load on a circuit does not warrant changing the fuse that protects from a overload condition. I don,t see any safety concern with reducing the load but I think your batteries will be very happy.

I do see a safety concern.

Case in point...Chevrolet Van/Bus conversion. Van originally had a 15A fuse for "marker" lamps. Conversion company changed all "marker" lamps to LED, with total amp draw of 1.2A. One LED went bad, (shorted internally) and caught fire. Fuse, 15A, never tripped. Fast action of a mechanic (disconnected the batteries) saved the vehicle. This is real world. Simple fuse change to 2A was implemented fleet wide.

John

**Herk7769** · 04-15-2011, 08:59 PM

Thanks John, I never thought of that. I will add up the total possible draw and re-fuse accordingly.

scubieman · 04-15-2011, 09:26 PM

I agree about the fuses. Because if the fuse is way to big it may not sense there is a power issue with one of the LED's. Therefore you want to keep the fuse as close as possible so if there is a issue it will POP right away.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!

LadyWindrider · 04-15-2011, 11:07 PM

Somewhere in post #3, "One LED went bad, (shorted internally) and caught fire. Fuse, 15A, never tripped. Fast action of a mechanic (disconnected the batteries) saved the vehicle. "....... I think we are missing the rest of the story. Why was the van in the shop? What were they working on that caused them to have the lights on? I have seen over a million LED's in my life, (17 years as a bench tester on telephone circuit boards), and I have never seen one catch on fire. I've seen smoke and lame from many electronic components, only for a short while, but never an LED.

Now with that said, I am not here to say a lower amp fuse could not or should not be used. The fuse or circuit breaker is actually put in to protect the wiring, because it often runs in walls and under floors, where it could start a fire that would be undetected for a while, or until it is too late. Necessary, I don't think so, wise, probably.

**Herk7769** · 04-16-2011, 06:15 AM

Yes, that struck me as curious too, but I accepted it at face value since I agree the smaller fuse is a good idea regardless of all the facts.

Most likely you are correct about the fire. Putting the blame on the LEDs that were installed by the owner; gets the blame off the technician and the dealership.

Would love to see a photo of the LED board.

kbrown1075 · 04-16-2011, 06:19 AM

I have to agree with windrider's post above. I have been an electronics tech (field and bench) for many years and have never seen solid state circuits flame up before. Seen smoke, seen charring. Fuses and breaker sizes are selected for the AWG and code rating for the circuit. On your AC in your house, you have your outlets in your bedroom, most likely rated for 15 amps. If you plug in a 10 watt florescent lamp into one outlet, 0.08333 amps, you don't go change out your breaker in your panel. On DC, if the wires going to the lamps is 14 AWG then a 15 amp fuse should be applied, 12 AWG 20 AMP fuse. Application Charts . The OP is defineitly adding additional safety factor into the circuit and there is nothing wrong with that. I would mark the fuse panel door with a note as to what fuses were changed and what the origanl fuse was. If you sell or change back to incadesent bulbs down the road, the buyer/ or yourself will know what the circuit is truly rated for.

**Herk7769** · 04-16-2011, 06:32 AM

Quote:

Originally Posted by kbrown1075

The OP is defineitly adding additional safety factor into the circuit and there is nothing wrong with that. I would mark the fuse panel door with a note as to what fuses were changed and what the origanl fuse was. If you sell or change back to incadesent bulbs down the road, the buyer/ or yourself will know what the circuit is truly rated for.

Another excellent idea.

kbrown1075 · 04-16-2011, 06:39 AM

I keep thinking about the auto shop blaming the LED for a close call fire.... it really has me thinking "how"? Ya'll have computers, right? all those blinky lights are on the front and back (and inside) are LED's! Never seen one "burn up". Seen power supplies in computers burn out and cause smoke. I have been a firefighter, also, for 25 years, and don't recall a computer starting a fire, never mind an LED. I just can't fathom how an LED can start a fire (I am not saying that it is impossible, anything can happen! but very unlikely). If the LED bulbs that you have purchased create enough heat to be uncomfortable to touch while on, then there is something not right. I could get into tech talk about biasing, voltage, and amperage of a diode but it would be boring. If I am missing something in the circuitry, please point it out. I am very curious as to how an LED could cause a fire.

**Herk7769** · 04-16-2011, 06:58 AM

The only components on that board are the LEDs (which do get hot when running) and micro-resistors. Resistors "pop" with a puff of smoke and since an LED is a light emitting diode (and I have see diodes blow), they also "pop" and emit a bit of smoke. Neither component will start a fire.

However a computer Power Supply most definitely will. My 450 Watt power supply failed one night. I knew because I leave the PC running 24/7 and just shut off the monitor. I came in in the morning and my PC was DOA.

When I pulled the Case away from the wall to troubleshoot, there was a huge black mark on the plaster where a lick of flame and smoke had come out of the fan vent. There was very little beyond that initial burst of bad stuff. The smokes did not go off (I have a centrally monitored system) in the hall. I was lucky there were no papers or other trash around or behind the unit at the time (like normally

). Since the supply was "toast" I opened it up and a big ripple capacitor had burst.

wfmdfm · 04-16-2011, 07:03 AM

Did you change the fuse size in your house to prevent it from happening again?

**Herk7769** · 04-16-2011, 07:05 AM

Quote:

Originally Posted by wfmdfm

Did you change the fuse size in your house to prevent it from happening again?

wfmdfm · 04-16-2011, 07:25 AM

Just messing with ya !!

SoMoney · 04-19-2011, 03:09 PM

Quote:

Originally Posted by wfmdfm

Did you change the fuse size in your house to prevent it from happening again?

I just switched out 50% of my bulbs for LED and I almost started to worry

.. I to have never seen an LED bulb burn and I've been using them in projects for several years.

The only mistake most people make is not paying attention to the color temp and ending up with Daylight LED's instead of Warm White LED's. The ladder is a more suitable incandescent bulb replacements in an RV's.

Warm White = 3000 Kelvin
Neutral White = 3500 Kelvin
Cool White = 4100 Kelvin
Daylight White = 5000+ Kelvin.

ken0042 · 04-19-2011, 03:41 PM

Quote:

Originally Posted by herk7769

The only components on that board are the LEDs (which do get hot when running) and micro-resistors. Resistors "pop" with a puff of smoke and since an LED is a light emitting diode (and I have see diodes blow), they also "pop" and emit a bit of smoke.

OK, question seeing as I know you have quite the setup for LEDs. I just bought some new LED bulbs and installed them yesterday. When I took the cover off the lens; there was a very small amount of smoke. Like small enough that I wasn't sure it wasn't my eyes playing a trick on me. I put the cover back on and waited 5 more minutes; and there was that tiny amount of smoke again.

Do your LEDs do that too? Or is this a sign that I shouldn't be using the ones I bought?

**Herk7769** · 04-19-2011, 06:23 PM

Quote:

Originally Posted by ken0042

OK, question seeing as I know you have quite the setup for LEDs. I just bought some new LED bulbs and installed them yesterday. When I took the cover off the lens; there was a very small amount of smoke. Like small enough that I wasn't sure it wasn't my eyes playing a trick on me. I put the cover back on and waited 5 more minutes; and there was that tiny amount of smoke again.

Do your LEDs do that too? Or is this a sign that I shouldn't be using the ones I bought?

My LED pads DO NOT smoke.
They know it causes cancer.

Seriously though, A photo of the type you installed would be helpful.
Are you sure they are 12 volt?

ken0042 · 04-19-2011, 08:08 PM

OK, the bulbs I bought are these ones: Link

I've attached a few pictures, bassically showing what they look like on, off, detached, and compared to a regular bulb. (May not look it, but I'd say the LED is about 75% as bright.)

Now of course tonight I couldn't see any smoke; so I'm wondering if there was some residue on the bulbs from manufacturing, and that burned away yesterday. I'm heading back into the trailer now to see if leaving it longer helped.

**Herk7769** · 04-19-2011, 08:30 PM

That was my thought as well. Oils on the unit burning off. Also the upper LEDs are quite close to the metal shields and could be overheating.

Shasta1 · 04-20-2011, 12:20 AM

In my (limited) past experience, if something was going to pop, it was the resister in front of the led. In your bulbs I believe there is one resister for each row of the three led's.

I don't see any led's out, so I doubt if any smoke you may have seen was the result of any failure.

Because of the design of the bulb and the way it's mounted in the fixture, a little less than half of the light is reflected light. There will be more heat reflected back to the bulb on top, but I don't think it is a problem. If I were to use a bulb of this design, it would be in the type of fixture that is more like a table lamp where the light is desired to radiate 360 degrees.

I installed the lights that herk7769 suggested not only for the fact that they're a great price, but they all fire downward in the fixtures I installed them in. Their easily as bright, and cover the area sufficiently as the bulb they replaced.

On the fuse issue, I'm considering fusing each fixture with an in-line miniature blade type of fuse, depending what other usage is on the same circuit (ie; I just added a Fantastic Fan and took the power from one of my ceiling fixtures). Plenty of room in the lens and very simple to install/change.

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