An update.
I want to make it clear that this thing is pretty big. There is only one fan and it is least 10 or 12 feet in diameter. and the blades are shaped like an airplane wing. The tower is about 2 stories high.
First I climbed up there and manually turned the fan to make sure that the bearings were not locked up.
Got all the contactors and overloads and installed. Fired it up and the fan did not move. Finally figured out that there was at one time dampers on the top of the tower that were taken down and the damper motors left on the tower. There is an aux switch in the motors to lock out the fan if the damper is closed. Jumped it out and the fan worked.
I wonder if the aux switch caused the contactors to chatter which caused the damage?
The motor is in fact a two speed one winding. First one I have seen. The contactor and overload setup is very similar to a wye delta type starter.
As for replacing the motor and controls, there is talk to replace the entire tower in a few years. As I work in house for a government agency part of my job is to keep worn out equipment operating untill they get around to replacing it.
Set all overloads to manual reset.
Thanks for all your help.
