Arcadia t5 fixture catching fire

[jamest0o0]

Just wanted to put it out there that my fixture holding just a uvb bulb caught fire today for seemingly no reason. Been in the same spot on a timer for a year and a half. I’m trying to think if it was something I could have done, but nothing changed or stood out to my knowledge. My wife called me at work to say the whole room was filled with smoke smelling like plastic. Luckily, kids weren’t home and she got it off and aired out.

 

[jamest0o0]

Now I am afraid to ever use a t5 fixture for a UVB bulb/anything again lol… is there any alternative or safety measure for something like this? Seems like a massive risk even if it’s like oh well our light fixtures MIGHT catch on fire sometime years down the road. Could be your house or worse gone in the wrong situation….

 

[LizardLurkin]

That is scary....Would being on a dimming thermostat not help? I assume it was on some sort of zoomed timer power strip or something of the like. This is definitely something to think about. I have my heat lamps on a thermostat but I never considered the uvb fixture!

 

[jamest0o0]

It wasn’t the hood that caught fire from being hot, it was the connectors where the bulb hooks up to, I didn’t even have a bulb in that socket, just the one uvb.

It was plugged into the wall with a regular timer.

 

[ehdee6]

That's frightening, thankfully someone was home to catch it!

The only thing I can think, is maybe by some off chance, water/condensation got into the bulb socket?

Do you have pictures?

 

[MissSkittles]

It wasn’t the hood that caught fire from being hot, it was the connectors where the bulb hooks up to, I didn’t even have a bulb in that socket, just the one uvb.

It was plugged into the wall with a regular timer.

This is terrifying! I’m not understanding what part caught fire though, Is it where the plug goes into the fixture or where the ends of the bulbs go in? Would a power surge cause this?

 

[nightanole]

Me and fish bro have been running these for close to 2 decades. You need to have "something" in all your sockets. If you have nothing, well its using a 600-1000v charge to start the bulb up, and it can arc. So your dead sockets are charged and read to light a bulb, but there is no bulb. You can prevent this by smearing dielectric paste/grease in your sockets (a good practice for fish tanks).

Im a little boujee so i use the good stuff

https://www.amazon.com/dp/B005RNEH5O

 

[nightanole]

This is terrifying! I’m not understanding what part caught fire though, Is it where the plug goes into the fixture or where the ends of the bulbs go in? Would a power surge cause this?

socket Arc fault from not having a bulb in the socket. Nothing would have prevented it other than having a bulb in the socket, even if it was a dead bulb.

Unless your fixture/ballast says you can run less than the amount of sockets, dont. You basically have two bare wires very close together running at wall voltage(higher when starting) with the electronics just limiting the current.

 

[Motherlode Chameleon]

Woww! That is crazy. I have heard of normal light and sockets catching fire. However UV bulbs catch fire is a major concern. Especially for those keepers that have got Reptile Rooms with multiple plugin and light outlets.

Best Regards
Jeremy A. Rich

 

[jamest0o0]

socket Arc fault from not having a bulb in the socket. Nothing would have prevented it other than having a bulb in the socket, even if it was a dead bulb.

Unless your fixture/ballast says you can run less than the amount of sockets, dont. You basically have two bare wires very close together running at wall voltage(higher when starting) with the electronics just limiting the current.

Pretty irresponsible for a company to not advertise this as a huge warning then. I work in a high intensity environment, my brain isn’t thinking when I get home, let’s over analyze a light fixture that has worked for a few years this way. While I totally believe what you’re saying and it’s great to know, let’s be honest how many of us knew this? The consequences of it are crazy and it’s being brushed off as something like it’s common knowledge. When your kids are endangered it just rings differently, if you don’t have them you don’t get it. I hold myself responsible as well don’t get me wrong. I’ll definitely over analyze and learn from this, but it could go not so well for someone else that doesn’t know any better. Sure you could fault me for not cruising through every detail of how a light fixture works, but think about how often anyone, anywhere actually does that. Human error is real regardless of how capable you are otherwise. Something this risky should have a big look here stupid label on it lol.

 

[nightanole]

Pretty irresponsible for a company to not advertise this as a huge warning then. I work in a high intensity environment, my brain isn’t thinking when I get home, let’s over analyze a light fixture that has worked for a few years this way. While I totally believe what you’re saying and it’s great to know, let’s be honest how many of us knew this? The consequences of it are crazy and it’s being brushed off as something like it’s common knowledge. When your kids are endangered it just rings differently, if you don’t have them you don’t get it. I hold myself responsible as well don’t get me wrong. I’ll definitely over analyze and learn from this, but it could go not so well for someone else that doesn’t know any better. Sure you could fault me for not cruising through every detail of how a light fixture works, but think about how often anyone, anywhere actually does that. Human error is real regardless of how capable you are otherwise. Something this risky should have a big look here stupid label on it lol.

Im not saying your hood unparticular. But ive changed dozens and dozens of balasts. Plenty do not run right if there is not the correct amount of "good" bulbs in them. If one bulb fails, half the time the other(s) will fail to start or run pink or something. Plenty of ballasts are rate for replacing in "one to two bulb" or "two to four bulb" so you dont need as many ballasts on hand. And im sure you have seen a ton of schools/offices with 1-2 bulbs out on a 4 bulb fixture. Its not a fire hazard, its just going to run funny.

But dont sell yourself short, you really did nothing wrong. Odds are there just got enough crud between the exposed high voltage prongs to cause and arc.

Here is a picture of a failure at my shop i had to deal with. As you can see It had a good arc going even with a bulb in it, and if it wasnt for the fact the entire fixture was made of metal with no plastic diffuser, odds are we would have had a fire.

But to keep my ballasts happy, if a bulb fails, ALL the bulbs in the fixture get replaced. Else now i have a poor ballast with 1 easy to start fresh bulb, and a hard to start old bulb, and they both get started at the same time on the same circuit/electronics.

Now i do rotate out my UVB T5HO bulbs as the uv wears out, but the bulbs are still bright and good. Then they become just 6500k bulbs for another 5+ years.

On a final note, my $$$ zoomed aquarium dual bulb T5HO, wont even run without two bulbs. If one bulb dies, the other just runs very dim.

 

[jamest0o0]

I appreciate the feedback I’m sorry for ranting, I was just really bothered by the thought of how bad that could have been at the wrong time. I also love having animals, and was thinking of just scrapping the hobby if lights are just doomed to catch on fire at some point. I’m relieved to at least know why that happened.

Thanks again and the info is very helpful @nightanole

 

[jamest0o0]

Im not saying your hood unparticular. But ive changed dozens and dozens of balasts. Plenty do not run right if there is not the correct amount of "good" bulbs in them. If one bulb fails, half the time the other(s) will fail to start or run pink or something. Plenty of ballasts are rate for replacing in "one to two bulb" or "two to four bulb" so you dont need as many ballasts on hand. And im sure you have seen a ton of schools/offices with 1-2 bulbs out on a 4 bulb fixture. Its not a fire hazard, its just going to run funny.

But dont sell yourself short, you really did nothing wrong. Odds are there just got enough crud between the exposed high voltage prongs to cause and arc.

Here is a picture of a failure at my shop i had to deal with. As you can see It had a good arc going even with a bulb in it, and if it wasnt for the fact the entire fixture was made of metal with no plastic diffuser, odds are we would have had a fire.

View attachment 368332

But to keep my ballasts happy, if a bulb fails, ALL the bulbs in the fixture get replaced. Else now i have a poor ballast with 1 easy to start fresh bulb, and a hard to start old bulb, and they both get started at the same time on the same circuit/electronics.

Now i do rotate out my UVB T5HO bulbs as the uv wears out, but the bulbs are still bright and good. Then they become just 6500k bulbs for another 5+ years.

On a final note, my $$$ zoomed aquarium dual bulb T5HO, wont even run without two bulbs. If one bulb dies, the other just runs very dim.

Also so if this happened even with a bulb in it. How do you make sure it doesn’t? In my perfect world one day, I’d like to dedicate a room to a bunch of critter displays. With all of the lighting, how do you make sure a fluke like this doesn’t happen with the lights?

 

[nightanole]

Also so if this happened even with a bulb in it. How do you make sure it doesn’t? In my perfect world one day, I’d like to dedicate a room to a bunch of critter displays. With all of the lighting, how do you make sure a fluke like this doesn’t happen with the lights?

The only way i know how is to use dielectric grease/paste on the metal contacts in high humidity environments. Id say the top of the cham cage is pretty moist.

But it pretty much goes like this:

Moisture is going to condensate on the coldest thing. Copper contacts are going to get colder faster that most objects in the cage.
Over time salts and other conductive material will build up, and at the same time the bulb and its contacts will become more resistive.
If a contact fails (there are many safeguards) its going to arc to ground or neutral. In my picture, the contact broke down enough that it arc'd to the grounded chassis.

Now i have only seen 5 arcs in 15 years. And unfortunately it was all from above, so it think its just a design flaw.

So apply a good amount of goo to the contacts to act like and insulator incase the contact get warndown/damaged etc.
AND get an inline gfci or replace the wall outlet with a gfci. Then any time you get an arc to ground, it will insta trip.

Since i am paranoid, also make sure the chassis/hood is really connected to the ground prong, and its not there for just looks