Converting an HPS Ballast into a Switchable MH/HPS Ballast

[charlesweedmore]

pictures are dead

 

[Philosophelon]

Ok, wait a minute. I changed some ballasts from HPS to MH, but I did not install a switch to make them switchable. I disconnected the ignitor, and swapped the HPS capacitor for a MH cap for the same bulb wattage. It works, but I don't want to start a fire. I'm pretty sure that it's kosher, safety-wise, but better safe than sorry.

So my question is, if I'm not using a switchable ballast, do I still need two capacitors?

Also, is there a significant difference in HPS and MH transformers?

 

[dansbuds]

with a 150 hps the cap's are the same as a 175mh ( if I remember right) all double check tonite

420 ..... is this info correct ? i'd love to change the 150 hps i use for veggin to a 175 mh . i can get the 175 watt bulb here localy & cutting out the ignitor is no prob . but can't find spec info on the caps in both fixtures unless i can source an online parts cataloge somewhere .