Found this; thought I'd share. It lists helpful specs (like arc current and minimum OCV) for quite a few kinds of fluorescent lamps.

http://code-elec.com/content/00/01/53/48/38/userimages/fluorescent%20ballast%20troubleshooting%20guide.pdf

However, can anyone explain why the minimum OCV for a certain kind of lamp changes based on the starting method (preheat/RS) or number of lamps? For example, the minimum OCV for an F40T12 is 176 on preheat, 200 on single-lamp RS, and 256 on two-lamp RS. I'm especially confused about it changing based on the number of lamps. I feel like that shouldn't make a difference.

nice, detailed guide!

I'm especially confused about it changing based on the number of lamps. I feel like that shouldn't make a difference.

If two lamps are operated in series, the OCV should in theory be double the requirement for one lamp. That also explains why in Europe, even with the same 36 watt ballast, two 18 watt lamps in series require two starters of 120 V whereas the same ballast operating one 36 watt lamp requires a 230 V starter. I imagine the same would apply to RS. As for the difference between the OCV in North American preheat versus the North American RS, the preheat can supply an inductive kick when the starter opens while the RS does not.

In other words (and to simplify) you can operate a single 12V lamp from a 12V battery. If you build a circuit with two 12V lamps in series, you would need 24V to operate at proper brightness.

Hope this makes sense.

I completely forgot about the lamps being in series. That makes sense.

Except preheat, for twoseries lamps the OCV does not have to be really double, because first the voltage does not split equally and "hot" side lamp sees gigher electrical field towards the reflector (and in fact this is, what determine the real ignition). You may notice the cmall capacitor across thehot side lamp: It ensures, thefull OCV reaches the "cold end" lamp and ignites it first, while the "hot side" lamp still sees the full OCV towardsthe reflector.
That mean when a certain lamp need ~200V when single, ~250V is sufficient for a series pair.

For preheat ballasts the OCV is dictated mainly by the starters: The 100V starter (for up to 70V lamps) need >100V at some crrent to close and when these are in series, because ofthe currentthere the voltage splitrather equally, so for series F18T8 you need at least 200V and so on. The OCV then does not affect the ignition, as the starter generate ignition voltages up to 1kV (assume an inductor in path), so unlike the other styles, the ignition is not the limit.

Wow, that's a really neat guide! It seems Advance were keen enough to cover almost all the bases that, well, we do! 

Wow that is a great guide.  Stashed it in iBooks 

on a preheat you get a spike when the starter opens.not so with rapid start.