metal halide

[enireh]

I changed out a 175 watt metal halide bulb and it worked once and burned out, put another one in and the same thing happened. Ballast is new. There was a bit of water in the fixture so I did dry it out. When I put the bulb in, fixture was dry. I put a 50 watt in the other day and it worked two days and quit.

 

[iwire]

enireh. you cant use any lamp with any ballast, a metal halide ballast will only work properly with a matching lamp.

 

[ptonsparky]

enireh. you cant use any lamp with any ballast, a metal halide ballast will only work properly with a matching lamp.

And if the ballast is new, and at one point you had the correct lamp, the ballast is wired wrong.

 

[TerryBarnhill]

Make sure you have Pulse start / Probe start correct in your lamping.

 

[JFletcher]

You cant assume the bulb that was initially in there was correct. Look up the fixture model #/mfg and get the correct bulb for it; wattage, type (MH, HPS, etc) and position. The ballast is new; what about the capacitor and igniter? Is the screwshell good

If there is water in it, there's probably a bad gasket, loose/missing threaded blank, loose/missing screws, etc.

Here's a good article on lights:

http://ecmweb.com/content/art-troubleshooting-arc-discharge-lamps

and a pic of typical wiring: