fraydo

Thanks for the info guys! I'm the replacement lamps and the original ones match the ballast but I did not pay attention as to the orientation on them. I'm sure the tech that changed them out didn't either. He has to go back and replace some ballasts so I'll let him know to check the lamps for their op. range

jahaiap

There is an appartment complex I service regularly now that had lamps that looked like that. The envelope never shattered, but the arc tubes on all of them were like that. There are 68 of these fixtures in the complex and about 40 were that way. They were 175mh in wallpacks, horizontally mounted. I always thought they may not have been rated for horizontal use because so many were out. I was told they were all original lamps and ballasts. I guess it took the complex 20+/- yrs to find someone with a ladder tall enough to reach the lamps .

lightinggod

That would be a normal condition for a universal burning position lamp operated in a horizontal position. If you look at the arc in the arc tube while the lamp is operating, you will see that the arc curves towards the top of the arc tube, this is what caused the condition shown in your photos. If your fixtures are equipped with hor sockets, you can use a hor lamp, and prevent this from happening.

Toronto Sparky

Watch life expectancy drop when a quartz lamp is off horizontal.
Put one vertical it dies in minutes.

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