what happens when the inline fan on a cool tube fails?

Everything fails eventually. I'm just wondering... short of burning my house down... if/when the inline fan cooling my cooltube were to stop working, what happens? Is there some sort of safety in a grow bulb that will shut it off (or melt) when it hits a certain temperature?

I have to imagine its happened to someone out there -- so thanks for sharing the info.

(And I did do a search or three, this seems like an obvious question that must have been covered, but I found nothing.)

There's definitely no safety feature built into light bulbs which protect against damage.

That being said, it's unlikely that a bulb will melt itself. The likely outcome of your cooling system failing is your plants being burnt to a crisp.

In theory you could set up your light controller to shut down the lights if temps reach a massive temperature, or at the least have a thermostat which can alert you to high temps.

Not to sure to be honest. For peace of mind I got one of those fire extinguishers that you can hang up in a room. If the temp gets over something like 140 it automatically explodes sending fire retardant all over the place. I'd rather have a ruined grow than my house burning up.

dubekoms said:

Not to sure to be honest. For peace of mind I got one of those fire extinguishers that you can hang up in a room. If the temp gets over something like 140 it automatically explodes sending fire retardant all over the place. I'd rather have a ruined grow than my house burning up.

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This is a great idea! I'll be looking into that for myself.

Thanks all -- I'm not worried about losing a bulb or a grow, more like burning the place down. I'm not sure what the melting temp of glass is, but I'm hoping the internal components of the bulb would fail (and the bulb would "shut off") long before either the bulb glass or the cooltube glass would crack/shatter/melt/explode.

fn217 said:

This is a great idea! I'll be looking into that for myself.

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The DIY section should have some thermostat setups you could use to set something of a fail-safe up.

You could make one easily for ~15-20 bucks.

You can get a high temp shutoff switch.

https://www.google.com/search?q=grow+light+high+temp+shutoff&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari

MichiganMedGrower said:

You can get a high temp shutoff switch.

https://www.google.com/search?q=grow+light+high+temp+shutoff&ie=UTF-8&oe=UTF-8&hl=en-us&client=safari

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There ya go, this is exactly what I was waiting for someone to post.

Here's some info that might help you sleep a bit better.
https://www.reddit.com/r/hydro/comments/2bwygy/what_would_happen_if_my_1000w_bulb_were_to/

Melting point of glass is roughly 2800F.

I think the point is, don't worry too much. Get your shut off switch, set up a temp controlled fire extinguisher if you really need to.

Hot or old bulbs will result in a warmer ballast.

For example, S51 400 hps bulbs will pull an extra volt from the ballast every 500 hours used.

The very same bulb is designed to operate within 84-115V and hits the end of its life at 140v, the hotter/harder you run your bulb the faster you will get there.


The fuse on a high powered ballast is rated high enough to not trip during bulb strikes during power up, which can give enough time to melt/start fires before popping the fuse.

Yes I've seen melted nanolux power supplies, gotta be careful.