Hey, I just got a hps light fixture to use. I am very cautious about wattage but know enough that I would rather use hps than my current cfl set up. It is a 150w. I understand the ballast uses wattage as we'll so I checked the label on the side and it says it uses 170 watts. But at the same time running off 120v of course but 3.2 amps? According to ohms law I now have a third wattage rating. Volts x amps = watts = 384 w? So which is it? I was thinking that it runs at the noted 170w but uses that 3.2amps/384w simply just for the pulse start the igniter needs to turn on the light. Anyone with any experience, knowledge or information know what this means? Thanks in advance
I think the ballest regulates the wattages for the bulb type. Is their a efficiency rating? If you HPS draws 150 watts at 100% efficiency it draws 150 watts. If it draws 150 watts at >90% efficiency then assume it will draw about 15 extra watts. These extra watts turn into heat. Tgis is the general idea, explained poorly.