MH turning red

[Blue_aerox]

I was just trying my MH 250w kit from Alan, as after 15 min it suddenly turned rose/red......
I got scared so I pulled the plug.
What is it?

[ace3000_1]

Either the bulb or the ballast, sounds like its the bulb to me, have a look at it and see if there are any hairline fractures in the glass inner or outer tube, the glass may have a hairline crack in it wich gass has suddenly escaped from heat preasure and exspansion. Also what burning position did you have it in? it has to be horizontal.


If its the ballast, it would have more the likley happend on bulb warm up which after 15mins the bulb has warmed up so i doubt its the ballast. If however it is the ballast, its incorect power to the lamp.

Trev

[Blue_aerox]

The bulbglass looks fine...
though the inner bulb is smurred with some yellow stuff on the inside.

I m using an Icecap 220Volt ballast I ordered from Alan. He said it was for european use.
Though, her ein th netherlands, the powercircuit has recently (a few years ago) been upgraded to 230Volt.

[Blue_aerox]

picture

[ace3000_1]

The 230v is fine, normally you can get away with as much as 15% in voltage diference on ballasts that are electronic, magnetic are about 3 - 5%.

I duno about heat issues, what u got around the bulb? if nothing then its not heat. Have you tried the bulb again? if not try it again with caution, it maybe just the gasses mixing cos its new, though its somthing ive never heard of before in respect of a mh bulb turning red lol.

Trev

[Blue_aerox]

Originally posted by ace3000_1
The 230v is fine, normally you can get away with as much as 15% in voltage diference on ballasts that are electronic, magnetic are about 3 - 5%.

I duno about heat issues, what u got around the bulb? if nothing then its not heat. Have you tried the bulb again? if not try it again with caution, it maybe just the gasses mixing cos its new, though its somthing ive never heard of before in respect of a mh bulb turning red lol.

Trev

It still works, but after 15 min it happens again......

[ace3000_1]

k sounds like its the soup laddel reflector over heating the bulb, its a common thing im finding out. I just finnished doing a big pile of tests on bulbs with over heating, i have had mine red hot, the bulb didnt change colour, however condensers self destructed very quickly and the anti tungstan ( the yellow crap in the innner arc tube) burns away to nothing shortening the life of the bulb.

Ive had mine that hot in the tests that the reflector i was using changed colour, ( an exspensive precision spherical), and that you can clearly see a heat trail in my light box where the super hot air went through lol, (was a white colour). Crazy as it may seem, its testing to the exstreme to make better longer lasting projectors.

Soup laddels are bright yess, we all know it, they are also cheap, but if you want to go and use cheap crap on a good bulb, you are simply playing with fire, the bulb over time will explode from being over heated. If the ink label on your bulb changes colour or burns off, its running far too hot, that also goes for any whitness you may get in the soup laddel and any discoulourisation anywhere else.

The outer bulb takes upto 650deg c, ( thats what its tested at), its meant to be run at 300deg c, (enclosed!), the inner tube runs at 650deg c all of the time and can take upto 800deg c. Fail to comply with those limits and your going to get a boom. A normal shperical reflector puts the bulbs center arc tube on its limits as it is, and the more light you reflect at such a close distance to the lamps arc tube, the hotter the arc tube becomes, ie soup laddel.

Trev

[Blue_aerox]

so what kind of reflector do you recomend icw my lightbox?
Ill dump the soupladle for sure. Lets see if that sucker will burn in gasoline

[ace3000_1]

I got a few shperical here that would work in your light box and on that bulb, its the same ones i use in my design actually, though i think you may have to make a size ajustment to your light box using any reflector as most reflectors have their bulbs sitting on top of them and not in them like the soup laddel. Hit me with an email if your interested.

Trev

[Tiarb]

Argh!
I just got my first MH and tested it in various configurations and the decided to try the SOAP LADDLE WAY that was descriped as A WORKING WAY in the PERMANENT THEORY THREAD ON THIS FORUM and what do I see? Yea it work nicely, really good beam, better then with other methods I tried.... I had active cooling all the time, a fan blowing directly at the lamp all the time and what happens? RED/ROSE BLINK BLINK.... I shut it down, took the laddle and lense away and tried again, after warming up, blink blibk red/rose flashes! DARN! Is it totally busted now? There is small hints of yellow in the inner glass and so on but the bulb looks ok... just starts pink/rose flashing after warming up...


Regards
HB