Quote Originally Posted by britishcolumbia
an hps ballast will fire a MH bulb. But the the HPS has a strike voltage of 2500v and and MH bulb has a strike voltage of 600v. So the lamp life of a MH will decrease when lite with a HPS ballast
Thats why you take the igniter out of the circuit whern firing up a MH bulb - all these switchable ballasts do is isolate the igniter on a toggle ie.On=HPS Off =MH