Ah yeah let me know how it works out with the preheater. Yeah I'm pretty sure you'd run each lamp between one red and one blue with the starters wires to each lamp independantly. If I understand Trent, that's whay he meant but I don't know much in the ways of electrical with ballasts and stuff.
I saw the pics. The ballast is definetly on the door. And yep, 250W HPS. So were there two separate ballasts? Or did you just mean multiple coils? There are multi-wattage ballasts out there (100/175W MV, 100/150W HPS, 250/400W HPS) but they don't require additional coils.
The number of coils depends on the ballast type and the line voltage coming into the ballast. A single tap 240V 250W HPS ballast would be a 240V choke since the voltage doesn't need to be corrected. Just like with a F20T12 choke. On the other hand, a 120V single tap 250W HPS ballast would be two coils since the voltage needs to be stepped up. This is a primary and secondary coil ballast just like an F40 ballast, because on 120V, the voltage needs to be raised. Just like how on 240V, F40s can use chokes. Making some sense now? The only difference is that the ballast is bigger and not potted inside a case.
Was there a capacitor? (Silver case with two wires coming out of it?) If there's no capacitor than that means it's not a CWA. If you can get pics of the inside I can probably help a little more...
Yeah totally! I can trade you a fluorescent for the M-400A. I'm more of a small cobrahead person too but I love the 70s and 80s HPS stuff. Well, if it's 120V that is...