Small Fire in LED light - Forward Head - see word attachment


Chris Paul
 

Hi Amelians,
We had a small fire in a LED light.
Luckily it was quickly found & dealt with.
See word attachment for full details and photos.
I wanted to share this with the group as it is a safety issue.
Maybe others have experienced similar problems.
Thanking you in advance.


Regards,
Chris Paul
SV GLAZIG
SM 352
Bay of islands NZ


 

Chris,

Thanks for the information because you included some things that are easily ignored by many of us and we all need a reminder.
  • The 24-volt circuit that this fixture is on was designed to carry a working load of up to 10 +/- amps. I believe that the original breaker for this circuit is between 10 - 16 amps. 
  • I am not sure if you have the original breaker, but chances are you do. 
  • I am not sure if the breaker is working, and you need to know.
  • The G4 2-prong bulb was originally a 20-watt Halogen Bulb that gets extremely hot and is known to cause issues with bulb recepticals and fixtures. 
  • The bulb receptacle is likely to have been damaged before the changeout to LED.
  • Flickering lights are BIG RED FLAGS of a circuit that has poor connections, which can include corroded bulb sockets and loose or improper connections. These should be inspected and corrected. Tapping is not a correction.
I believe that the original design was fine for the fixtures, bulbs, and normal use. The original design was partially modified by you or a previous owner without a complete understanding of its design, a Chinese LED bulb of unknown quality was used, and a RED FLAG was ignored.

Bill


CW Bill Rouse Amel Owners Yacht School
720 Winnie, Galveston Island, Texas 77550 
   


On Mon, May 30, 2022 at 8:49 PM Chris Paul via groups.io <chris__paul=yahoo.com@groups.io> wrote:
Hi Amelians,
We had a small fire in a LED light.
Luckily it was quickly found & dealt with.
See word attachment for full details and photos.
I wanted to share this with the group as it is a safety issue.
Maybe others have experienced similar problems.
Thanking you in advance.


Regards,
Chris Paul
SV GLAZIG
SM 352
Bay of islands NZ


Chris Paul
 

Hi Bill,
Thanks, lots of great advice. 

I will check circuit breakers work & replace all flickering lights.



Regards, Chris Paul (0427788800)


On Wednesday, 1 June 2022, 12:53:01 am NZST, CW Bill Rouse <brouse@...> wrote:


Chris,

Thanks for the information because you included some things that are easily ignored by many of us and we all need a reminder.
  • The 24-volt circuit that this fixture is on was designed to carry a working load of up to 10 +/- amps. I believe that the original breaker for this circuit is between 10 - 16 amps. 
  • I am not sure if you have the original breaker, but chances are you do. 
  • I am not sure if the breaker is working, and you need to know.
  • The G4 2-prong bulb was originally a 20-watt Halogen Bulb that gets extremely hot and is known to cause issues with bulb recepticals and fixtures. 
  • The bulb receptacle is likely to have been damaged before the changeout to LED.
  • Flickering lights are BIG RED FLAGS of a circuit that has poor connections, which can include corroded bulb sockets and loose or improper connections. These should be inspected and corrected. Tapping is not a correction.
I believe that the original design was fine for the fixtures, bulbs, and normal use. The original design was partially modified by you or a previous owner without a complete understanding of its design, a Chinese LED bulb of unknown quality was used, and a RED FLAG was ignored.

Bill


CW Bill Rouse Amel Owners Yacht School
720 Winnie, Galveston Island, Texas 77550 
   

On Mon, May 30, 2022 at 8:49 PM Chris Paul via groups.io <chris__paul=yahoo.com@groups.io> wrote:
Hi Amelians,
We had a small fire in a LED light.
Luckily it was quickly found & dealt with.
See word attachment for full details and photos.
I wanted to share this with the group as it is a safety issue.
Maybe others have experienced similar problems.
Thanking you in advance.


Regards,
Chris Paul
SV GLAZIG
SM 352
Bay of islands NZ


Tony Elliott
 

Chris,

It is important to know that, as Bill noted, the original circuits were designed for higher current draw devices - specifically the G4 Halogen bulbs. These bulbs draw amps (a 24 wattt bulb in a 24V system would pull 1amp for example).instead of milli-amps as is the case with most LED replacements.

The breakers are designed to protect and handle the higher current capability of the Halogen bulbs - typically several in parallel pulling 4, 6, 8amps or so. Bulbs like this, in general, fail by going open circuit - they "burn out" and the filament is broken - this reduces the current flow in the circuit when a light fails. There is generally very little in a filament bulb that can cause it to short which in turn causes higher current to flow.

The failure mechanisms for a voltage regulator circuit as used in these LED bulbs can be open circuit but invariably it is a short circuit which, if not properly fused, can lead to high current, heat and possibly fires.

So, when making what appear to be simple decisions about replacing a halogen bulb for an LED equivalent, due consideration should be given to the likelihood of failure (don't read the hype on the product labels as there are more failure mechanisms involved in the voltage regulated, LED circuit than there is in a Halogen filament bulb), the failure mode - invariably an internal circuit short, and the secondary method of protecting the lighting circuit. I will give you an example here that is applicable to my SM.

All of the original Nav lights on my SM had failed for various reasons. I chose to replace them with Hella LED Port, Starboard and Stern 2NM lights. In the manual accompanying the lights, it states that the light should be protected by a 3A fuse. The breaker on the 24V panel is 10A. If a short cct were to occur in one of the LED lamp regulator circuits, or a capacitor in that circuit blows for whatever reason, that circuit would be pulling more than 10Amps before the breaker would trip. Depending on the nature of the circuit failure in the LED lamp, that could last for a few seconds to possibly much longer, heating the wire, the breaker, and/or the circuit in the lamp  which could easily create a fire.

The LED lights only pull 0.08A (80mA) each at 24V so, in my case, I chose to open the breaker panel and insert a changeable fuse on the supply line to cater for this difference. Now, if a failure occurs, the 3A fuse will blow well before the breaker would trip and the likelihood of something like a fire is reduced significantly. The down side of this approach of course is convenience since the breaker panel needs to be pulled if the lights fail. It is likely that the Diruptor would not have tripped so to check the fuse you would need to pull the panel. I have not been able to find a 3A "Dirupter' in my inventory or anywhere else as this would be the ideal solution. An alternate is to mount a series of panel mounted fuses as you go through this process and connect the Diruptor output through the fuses as you change to LED's.

The moral here is that changing your existing light circuit technology has broader ramifications than you might think. 

FWIW.

Tony, 
SM#443, Grand Cru


Dean Gillies
 

Excellent advice Tony.


--
Dean Gillies
SV Stella *****,  Amel 54-154


 

Tony,

Excellent and I am going to quote you if it is OK.

Bill


CW Bill Rouse Amel Owners Yacht School
720 Winnie, Galveston Island, Texas 77550 
   

On Thu, Jun 2, 2022 at 12:03 PM Dean Gillies <stella@...> wrote:
Excellent advice Tony.


--
Dean Gillies
SV Stella *****,  Amel 54-154






Tony Elliott
 

Bill, by all means.

I'll give another example of this to expand the subject.

I recently bought a new VHF radio for installation in Grand Cru. In the package was a power cable with an in-line replaceable fuse. I've connected it to a switch on a Blue Sea DC Distribution panel that is at my Nav station that already has a higher current rated breaker than that rated for the fuse. The fuse goes in line after the breaker/switch to protect the radio. The DC panel is a standard commercial product with, I believe, a variety of breaker ratings (for a total of 45A) but the supplied fuse and in-line receptacle is that recommended and supplied by the accessory manufacturer. If it is in place and the radio fails and blows the fuse, you can clearly state to the manufacturer that it was protected using their recommended and supplied protection devices.

I have the same situation on a new RayMarine Quantum Radar connected to the same DC distribution system. 

Breakers are fine if they are changed to reflect any change in technology or purpose for a circuit but it is often overlooked. A simple fuse that matches the rating defined by the accessory manufacturer, while not as convenient as a breaker, is invariably a better choice for equipment protection and for possible warranty claims later.

I'll restate the moral statement I used earlier:

The moral here is that changing ANY existing ELECTRICAL circuit technology OR PURPOSE has broader ramifications than you might think. It requires careful re-consideration of protection devices. Better to blow a fuse or breaker early than having something "sizzling" in a place you may not necessarily be fortunate enough to hear!

Tony
SM#443, Grand Cru


Dean Gillies
 

And when you are adding that new fuse-holder + fuse don't forget to follow the Amel protocol of zipping a spare fuse to the cable nearby. If you do this then it is (almost) guaranteed that the fuse will never fail! 
--
Dean Gillies
SV Stella *****,  Amel 54-154


Paul Harries
 

Could these work?

RKURCK 3 Amps Thermal Circuit Breakers 125/250V AC 32V DC Push Button Manual Reset Overload Protector Switch 3A 2 Pack https://www.amazon.com/dp/B083Q55YHP/ref=cm_sw_r_apan_i_R9GCM4FQ8YW4J63FTTRG

--
Paul Harries
Prospective Amel Buyer