Author Topic: Can MH lamps be run safely with the top broken off?  (Read 1336 times)
thelightingman
Member
****
Offline

Gender: Male
View Posts
View Gallery
All lighting except LED rules!


Can MH lamps be run safely with the top broken off? « on: October 23, 2021, 12:23:56 AM » Author: thelightingman
I am just wondering because I recently accidentally broke the top glass of of my 175 watt probe start MH lamp. Would the UV output be too extreme to safely run it? thanks  :)  :bumh: <--this is the shape of the lamp
Logged

I think HPS, MV, and MH rule! :mv: :mvc: :hps: :emh: Ban LED instead! :eoled:

Foxtronix
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Formerly "TiCoune66". Also known here as Vince.


GoL UCs4tSgJSCoCIMGThBuaePhA
WWW
Re: Can MH lamps be run safely with the top broken off? « Reply #1 on: October 23, 2021, 12:30:38 AM » Author: Foxtronix
Some UV is going to escape from the opening. Looking at the (operating) arctube through that opening isn't a good idea, needless to say!

Since the bulb is now filled with air, and namely oxygen, the arctube seals will fail eventually. It takes a while though, so the lamp should run for some time before it happens. But expect it nonetheless.
Logged

thelightingman
Member
****
Offline

Gender: Male
View Posts
View Gallery
All lighting except LED rules!


Re: Can MH lamps be run safely with the top broken off? « Reply #2 on: October 23, 2021, 12:58:14 AM » Author: thelightingman
Ok, Thanks. this lamp will most likely be used in an enclosed fixture. Now just to find a proper 175 watt MH fixture...
Logged

I think HPS, MV, and MH rule! :mv: :mvc: :hps: :emh: Ban LED instead! :eoled:

Medved
Member
*****
Offline

Gender: Male
View Posts
View Gallery

Re: Can MH lamps be run safely with the top broken off? « Reply #3 on: October 23, 2021, 06:18:17 AM » Author: Medved
On top of the UV, it will poison the room by ozone (O3), once the atmospheric oxygen becomes exposed to the UV from the bare arctube.
Plus the air has way different convection properties, so the running themperature will likely be way off what the arctube is designed for.
Plus some starting resistors will start to degrade pretty fast in the presence of the UV + O2 combination or even in the presence of O3 (or an atomic oxygen), the carbon layer is just burning off, so after a while the resistor won't be able to start the lamp anymore.
Logged

No more selfballasted c***

thelightingman
Member
****
Offline

Gender: Male
View Posts
View Gallery
All lighting except LED rules!


Re: Can MH lamps be run safely with the top broken off? « Reply #4 on: October 23, 2021, 02:26:55 PM » Author: thelightingman
It will most likely be used outside.
Logged

I think HPS, MV, and MH rule! :mv: :mvc: :hps: :emh: Ban LED instead! :eoled:

sox35
Guest
Re: Can MH lamps be run safely with the top broken off? « Reply #5 on: October 23, 2021, 05:40:47 PM » Author: sox35
I can't see that it'll last long outside, probably better to get a new lamp, you'll have to sooner or later, most likely sooner  :-\
Logged
thelightingman
Member
****
Offline

Gender: Male
View Posts
View Gallery
All lighting except LED rules!


Re: Can MH lamps be run safely with the top broken off? « Reply #6 on: October 23, 2021, 05:48:46 PM » Author: thelightingman
I can't see that it'll last long outside, probably better to get a new lamp, you'll have to sooner or later, most likely sooner  :-\
I don't have anything to run it in yet and if I find something to run it in, it might be temporary until I could find a fully intact lamp to actually use long term and the lamp in question would become a test lamp for any other other 175 watt probe start MH fixtures that I find.
Logged

I think HPS, MV, and MH rule! :mv: :mvc: :hps: :emh: Ban LED instead! :eoled:

Print 
© 2005-2025 Lighting-Gallery.net | SMF 2.0.19 | SMF © 2021, Simple Machines | Terms and Policies