Outdoor RGB LED Strip Failure

Hi all, 


I've had quite a modest installation of RGB LED tape (45 meters ish, split into more manageable circuits) around the perimeter of my decking. This uses the commonly available 5050 RGB LED Strip light, the type with the epoxy covering the tape and also an outer sheath to protect it from water ingress. 

I had heat shrinked the ends and also applied multiple layers of liquid electrical tape where a connection to a 4-core cable was needed. This has held up well for some time. 

After about 2 years, I noticed that some of my RGB LED tape runs were sort of 'corrupting' where a small amount of moisture had got in, and shorted the RGB channels so that no matter what I feed into the tape, it always output white (or some other combinations or colours). Still, I ignored this, as it didn;t bother me too much. 

These ran back to a central controller, which did the DMX control and amplification of the 12v single. 

Anyway, to cut a long story short: Yesterday I smelt smoke. 

I was walking around the garden and I noticed that one of the strips had caught fire, at a single point in the middle, and was burning a hole through my decking! 

Again, long story cut short, I put this fire out and looked closer. The strip was so badly burnt that I can't determine what went wrong here. 

I'm thinking maybe a resistor burnt out and caught fire? The tape has been running 'on' for quite some time (weeks) so this is a possibility. 

Another possibility is that there could have been a short between 12v and ground, which caused heat. Now, there aren't any fuses on the 12v rail (fuse and circuit breaker protecting the 240v side) but I wouldn't have thought that this would protect me from a fire anyway! 

I'm interested whether anyone else has had a similar experience or has any suggestions as to why this has happened. 

I love these RGB LED strips, use them a lot in my house, but after seeing this, I'm not a little more dubious to keep using them. 

I'm an electrical engineer (in the making, at University) and this has stumped me! 

Thanks
Joe

Downunder35m6 months ago

LED strips without testing certificates should be made illegal ;)
I assume one LED died and due to this it shorts the connection between positive and negative.
On a normal strip no big deal, "weatherproof" strips tend to start a fire as the resin used to cover all is highly flamable....

joearkay (author)  Downunder35m6 months ago

I agree. What worries me is I bought them from a respectable UK distributor and not eBay. I guess some inline fuses (like the automotive ones) wouldn't hurt. They would cut the power in the event of a large surge, but not exactly stop a fire!