Is it safe to run a 400watt GE multi vapor lamp without an enclosure? « on: March 06, 2026, 04:01:14 PM » Author: Waxsoda61774308
I recently purchased some 400watt MH gear and would like to know if it’s safe to run the lamp out of an enclosure. I do know that MH lamps have the tendency to sometimes explode apon EOL.
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	Re: Is it safe to run a 400watt GE multi vapor lamp without an enclosure? « Reply #1 on: March 06, 2026, 04:28:53 PM » Author: BT25
Running them vertically reduces the likelihood.
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	Re: Is it safe to run a 400watt GE multi vapor lamp without an enclosure? « Reply #2 on: March 06, 2026, 04:29:57 PM » Author: Multisubject
If it is an exposed rated lamp, then I would say yes this is probably safe. But assuming it is an enclosed rated lamp (as most are), then I would say maybe. If the lamp is used (or you don't know it's history), I would not at all run it in the open. Technically even a brand new lamp can explode with a severe enough manufacturing defect, but I haven't seen that. Explosion is always a risk, but if you shield the lamp or shield yourself you should be relatively safe even with an old lamp.
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	Re: Is it safe to run a 400watt GE multi vapor lamp without an enclosure? « Reply #4 on: March 08, 2026, 10:33:52 AM » Author: dor123
There was a generic 6500K 400W elliptical clear MH lamp at Peamit Store, that exploded despite burned base-up in a highbay fixture: https://www.lighting-gallery.net/gallery/displayimage.php?pos=-251405
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	Re: Is it safe to run a 400watt GE multi vapor lamp without an enclosure? « Reply #5 on: March 08, 2026, 08:20:41 PM » Author: Waxsoda61774308
This is the lamp, it’s definitely not a shielded arc tube. It’s also new-old stock found in my churches basement after they got rid of their high-bays in favor of LED’s.
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	Re: Is it safe to run a 400watt GE multi vapor lamp without an enclosure? « Reply #6 on: March 08, 2026, 11:04:49 PM » Author: WorldwideHIDCollectorUSA
If your lamp has operating position restrictions, it is especially paramount to run it in its designated operating position such as VBU for base up or HOR for horizontal. If it is  rated for universal burning, it should safely operate in any position, but I recommend even operating universal burn lamps base up for maximum longevity.
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