Upside Down Halogen Bulb?

[RickyC]

Ok so I'm working on a little omni direcitonal light at last (after procrastinating it). I found some old small silk rags and duvatine and took appart a broken 1k fresnel.
I plan on making the "lantern"-like light a bowl shape, then have the light in the center....

But this is bugging me, I've never really considered it... but how bad is it for a halogen bulb, like an EGT 1000w, to be operating upside down?

I know some lights like HMIs and chimeras use the sideways, but upside down?


Just don't want the whole thing exploding, catching on fire and hurting anyone

 

[Richard Crowley]

EGT is rated for "Base Down to Horizontal"
ref: http://www.fullcompass.com/product/342692.html

There are many serious hazards from burning a lamp like this upside-down.
Up to and including explosion and fire. NOT recommended!

 

[RickyC]

EGT is rated for "Base Down to Horizontal"
ref: http://www.fullcompass.com/product/342692.html

There are many serious hazards from burning a lamp like this upside-down.
Up to and including explosion and fire. NOT recommended!

I was looking for something like that.
I figured there would be something against it, just wasn't sure. I'll work around with it horizontal.

Thanks!

 

[bclighting]

I don't know if this would work in your situation but you could use a HPL lamp out of a Source 4 for that. The max wattage would only be 750w but those lamps are used base up 50% of the time. You may have a tough time digging up a socket that could be used though.

 

[Moseph]

There are several lamps that can be burned in any position. FEL is one of the single ended ones that can.

 

[RickyC]

I don't know if this would work in your situation but you could use a HPL lamp out of a Source 4 for that. The max wattage would only be 750w but those lamps are used base up 50% of the time. You may have a tough time digging up a socket that could be used though.

There are several lamps that can be burned in any position. FEL is one of the single ended ones that can.

I don't know if this would work in your situation but you could use a HPL lamp out of a Source 4 for that. The max wattage would only be 750w but those lamps are used base up 50% of the time. You may have a tough time digging up a socket that could be used though.

There are several lamps that can be burned in any position. FEL is one of the single ended ones that can.

Hmm ok, I'll look into that. I figured EGT since I had a busted up baby fresnel here, but maybe I can pick up an old source4 or something.

Thanks!

 

[RyanT]

You shouldn't have any problem just buying the socket for an HPL globe, then you can just mount that onto whatever you please.

 

[bclighting]

There are several lamps that can be burned in any position. FEL is one of the single ended ones that can.

This is true, it's been so long since I've had to deal with them I forgot about that!

To RickyC:
Look around for old Altman 360Qs, they took FEL lamps and you may be able to score some of them from an old theater.

 

[Michael Carter]

The FEL is a pretty old-school, primitive globe (according to the theater guys). Newer, more efficient globes are GLA, GLC, (575w) and GLD, GLE (750w). The GLD is closest far as pure lumens go.

That said, most of the big bulb websites list burn position in their specs... look for "universal".

Another option for a lantern would be to have the fixture sort of "hang" (maybe not optimal for safety) or rest at the bottom of a lantern frame, keeping the globe upright.

 

[Moseph]

Most FEL lamps are listed as putting out 27500 lumens; the GLD is 19000. That would actually make the FEL slightly more efficient. The 575w and 750w HPL lamps are more efficient than the FEL though, and having a heat sinking base you wouldn't need to worry about them causing overheating in the socket as much.

 

[paulears]

We've been doing the 'wrong' thing in the theatre world for years. Back in the 60s and 70s we had one popular type that was designed for upside down use with the lamp holder at the top. As a consequence we had various types of similar looking lamps in the store rooms so we often got it wrong. Two things are different in these lamps. Upside down burning lamps have filament support systems that are different - it's all to do with sag. As the filament heats up it expands, and gravity has an impact - so they are designed to allow the sag to not impact on the operation, upside down burning requires swapping the support system around, that's all. Heat rises, so it's common on upside down burners to increase the glass envelope length to get the weak point - the join between glass and lamp holder a little cooler. Thes upside down burners (using ordinary tungsten lamps - as halogen types hadn't been invented yet) did very strange things. when they eventually died, the glass might be distorted, or have bubbles and lumps in it. It seemed that upside down burning didn't give the same lamp life, and most of us blamed excessive heat as the culprit.

Often when we ran out, we'd use the wrong ones as a stop gap. The main issue was simply lamp life. They would not last very long. It's common for theatrical lighting to be used at almost any angle - and even the 180 degrees the lamp people use horizontal to horizontal doesn't really help, because the common angles would be from straight down, to above horizontal - i.e a narrow angle, but still outside the ideal. We just put up with it - lifespan wise.

I'd urge caution with 575 and 750W lamps because the heat sink is VITAL because these things burn much hotter than the more common types, so although the heat sinks work, they do burn out the sockets still.

Homebrew devices with upside down 'wrong' lamps should just be very careful about the heat at the socket. Convection means the pin area will be very hot. Far too hot for normal cable. Silicone type cable is essential, complete with fibreglass braiding to help with the heat and flexing. In these kinds of products, the enemy is always heat!