HMI Head Shuts Off Randomly

T

tommygdawg

Well-known member
Hey, all

Question here regarding my Chinese HMI PAR(I know, I know). I was shooting the other day and it was on for probably 30-60 minutes (I've run it for hours continuously many times before) and it just randomly shut off. I had it outside in 80+ degree weather (the ballast was in good shade and sitting high off the ground). When I checked on it, the ballast was still running but there was no arc in the globe. So, I just shut it all off and decided to deal with it when I got home. Hours later, I plugged it in at home and all was fine. It struck okay, ran it for a while, no issues.

Is this likely just a cheap HMI issue, or is it possible there was an overheating issue outside? It seems if it was overheating that the ballast would shutdown as well. Any thoughts?

Thank you!
 
How many hours on the lamp? Heat shouldn't bother the fixture ( think of how hot that bulb gets) or the ballast, at least on any of the Arri's I've used, Head cable maybe? Do you have others you can swap out if it happens again?
 
That's what I thought regarding heat. It shouldn't be the globe since it's rated for a 1000 hours and I'm reasonably certain it doesn't even have half that. Unfortunately the Chinese lights don't have an hour meter on them. Could it have been the circuit I was powering it off? I was running a 50' stinger from an older outlet in a garage (never shot in this location before). I checked the breaker and it was rated for 20 amps, but if it's older there might be higher resistance and thus a voltage drop?
 
Power problems.
With magnetic ballast it would just flicker for a few moments when power "figures itself out" but with electronic ballast it shuts itself off. You should have tried a different outlet.
 
tommygdawg said:
Could it have been the circuit I was powering it off? I was running a 50' stinger from an older outlet in a garage (never shot in this location before). I checked the breaker and it was rated for 20 amps, but if it's older there might be higher resistance and thus a voltage drop?
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Unlikely that an older breaker would have high enough of a resistance to adversely affect the voltage coming out of the wall. You may be onto something though, it's possible that the circuit you powered it from had other issues. Unfortunately it's difficult to say exactly what went wrong. HMI's happen to be much less reliable than tungsten heads so it's not uncommon to see them having issues, and when something does happen usually it's a matter of replacing a faulty piece of equipment or reinstating power if a connection is lost. If a name-brand light randomly shut off after running that long, my first guess would be that someone kicked out the plug (and maybe tried to cover up their mistake). Since it's Chinese, you could have some QC issues, or it could have been some unforeseeable issue with the supply voltage.
 
Thanks all for the thoughts. I did try it again once I got home but as stated, since it was Chinese, I opted to go without it for that shoot because I didn't want to have to deal with the possibility that it was a QC issue when I was trying to run around and shoot. Considering it has worked fine since (and I've never had that issue before), I'd imagine it was likely something to do with the power coming from the location.
 
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