Swarfing, once the correct value cap has been established, apart from the "start" cap you are still only putting "C" across one leg of the delta (or am I missing something?). To give the correct "C" value you may well decide to use a combination of caps to achieve that value, but a single item of the correct value can usually be found. If Ross already has an inverter then obviously that is the best way ahead for him. I only make this point because I would not like to be thought of as misleading anybody. G.