I have a sun system 240v hardwired ballast (some are interchangeable cords). can i convert to 120 or can i use a 240v receptical wired to a 110v line and use the 240v ballast?
Not unless it is a multi-tap ballast. Does the ballast have other wires on it that are capped off with wire nuts?
yes you can convert it to run 110 but it's cheaper and a lot safer to buy a new ballast now that ballast prices are so low peace