I think what you meant was 220v*5amps = 1100 watts. All 1k ballast draw 1100 watts, the extra 100 is lost as heat and in inefficiency. But we already know its 1k ballast.

At 110v*10amps=1100 watts the same at 220. But because the cable only carries 5 amps instead of 10 it is more efficient.

I don't think your math is right breeder and what do you mean by ballast and lamp should be 1=1? 1v does not equal 1amp! Volt is potential difference and amps is how much juice is being drawn.
CrackLemonade Reviewed by CrackLemonade on . 1k HPS ballast plug getting warm, is it normal? I have a HydroFarm 1000 watt, switchable HPS/MH 9.8 amp ballast. The ballast has been used for about a year. Right now its on a 18/6 schedule. The plug gets hot, before i ask the question here is some more info. The power supply for the light is a dedicated 10 gauge cable from the breaker box with a 30 amp breaker at the box. I also got 20 amp outlets. I intended to run two 1000 watt ballasts on this line but right now I am only running one. I noticed the plug gets a little more than Rating: 5