ptwaugh,
I did some net cruising and found the explanation. That switch is the essential bus control switch, albeit poorly labeled. The TH-57 only has a generator and a battery, so electric power is minimal, and the battery will only last a short while after generator failure. The system dumps most loads automatically if the gen fails, including the fuel boost pumps and some lighting (I think). For safety, the pilot selects the "recover" position while flying in darkness to override the load sheding. See:
http://www.bryanweatherup.com/gouge/...CPT/cpt3.shtml