Is it a start capacitor {electrolytic short [4-second] duty, usually round, phenolic case} or run capacitor (continuous duty) film dielectric, usually oval, metal can)? 20 microfarads is more likely for a run application.
This does sound like a run type capacitor..and connection should be fairly simple to work out as your three wires out will most likely be from two windings, with a common,a run winding lead and a start winding lead.
If you need any more info,refer to: