Pretty simple unit, not much to go wrong with this one.
First thing I would do is open the unit and clean the inside.
Vacuum, compressed air, brush, ect.
Once clean, inspect for any obvious faults, burned cables, burned connections, overheated contacts,you get the idea.
When satisfied that all is well, determine the input voltage, have a qualified electrician take care of this if you do not have the skills or knowledge in this area. Install a dedicated electrical  circuit, complying with any applicable codes.
Depending on the age and model , the output connections could be lugs, plugs or bolt-ons,get a set of leads to correspond with the machine.
Tweco maks a very good line of connectors and terminals, I'd use them, if available.
  This should get you started, if any specific questions arise, post them, someone should be able to help.