lighting question
 

Hi, I have a 400watt M59 ballast that was running a 400watt iwasaki bulb. Yesterday I got a 400watt radium bulb and started it at about 6pm, lights turn off at 8pm, bulb fired up well and stayed lit but today the bulb will not light anyone know why?

Sometimes a bulb will do that for a couple of weeks. Leave it turned on and see if it fires after a while. Sometimes they just won't fire on a particular ballast.

I left the bulb running from 12pm to 8pm and it did not fire up once is there anything else I can do or just keep trying?

put the iwasaki back in just to mae sure the ballast is working. Make sure the contacts are clean, and maybe removing the bulb and putting it back will make it work. I had a 175w that did that for a couple of weeks. It eventually fired properly.

k thanks, i'll give that a try.