i notice sometimes when i switch power on to my Merc...the lamp sometimes will not Strike...but instead a Dim Glow Discharge Forms in the Arctube...it will sit this way anywhere from a Few Seconds to over a minute then out of the Blue it will Strike and the lamp will opperate Normally...what causes this?

It may be when the bulb (arctube) int cooled all the way. it happened with my merc fixture. I plugged it in, it idnt strike, but it did after a while.

It may be when the bulb (arctube) int cooled all the way. it happened with my merc fixture. I plugged it in, it idnt strike, but it did after a while.

this happens when the Bulb is first Powered on....and Compleately cool.

It may be just too old and the striking voltage too high, and the auxiliary discharge eventually produces enough ionisation to fire up the main discharge.