So
@mattyblade1 and
@TheStickMan got me thinking about the core and coil ballasts. Apparently the ones they ran made some noise. However mine doesn't with the only downside being some heat output. So I was curious how much power is dissipated with the use of this control gear (btw it's an ETI UAL T / CL1 HPS MH 250 <--- and they make them up to 1000 watts. Works with HPS MH and CMH). I've went on google first and I found some very bad information on other cannabis grower forums and later found that the same information was pasted on several others. The claim came from a person who says he/she is an electrical engineer and stated that a 150 watt core and coil ballast with an HPS bulb will run at about 300 something watts*h; I can't recall exactly but it was something preposterous.
The basic formula for apparent electrical power is: voltage across element * current through element. Element here being the 250 Watt HPS bulb (265 watts says on the spec sheet<-- it'll make more sense later) which is rated at 115 running Volts and 130 max. warm-up volts (first minute or so) and 2.6 Amps.
Now my control gear is "compact" meaning it can't be torn apart and put back together so I can't show you pics of its guts but I know inside there is an inductor (heavy iron core with copper wire wrapped around) and capacitor (cylindrical thing) and an ignitor (plastic box thing). The inductor stores electrical energy in the form of magnetic energy and the ignitor (it has more coils in it and a resistor) creates the right voltage pulse (about 3.3 kV) to spark the arc without creating RF noise. By virtue of its design the capacitor regulates the power to the bulb once it stabilizes. and it stores electrical energy in the form of electrostatic energy <--- similar to like when you're trying to pet your cat but you get a small shock of electricity.
I think I am getting sidetracked here. Anyway the entire circuit system creates a phase difference between the voltage that the bulb runs and the current drawn and this is the power factor. The power factor, in a triangle, is the angle between apparent electrical power and real power... which is what we need... so we can calculate it. The ballast is rated at power factor of 0.9 and the formula for real power in single-phase AC is apparent power * power factor. (actually it's volt * ampere * cos angle between apparent and real power, but there's no need to get even more in depth). So in theory:
115 * 2.6 * 0.9 = 269.1 Watts --> 0.2691 kWh power consumption total
I say not bad. But this is just theory not considering warm-up and other parameters. I think I might buy a kill-a-watt meter later today and see it for myself... just for kicks.
I hope it makes sense
EDIT: I forgot to mention I also looked at the specs of "non-agro" or "non-spectrum-enhanced" and the bulbs apparently run a much smaller voltage. So finally there's some evidence that the enhanced HPS bulbs might actually have something added to them. The CMH run both insanely better spectrum and lower voltage. You're probably wondering wouldn't a lower voltage create a bigger phase difference hence altering the power factor. Welp... no. The capacitor corrects the phase