This publication provides electrical engineers and other professional engineers and construction managers with an introduction to operation and maintenance of generators and exciters for auxiliary electric power generating systems. Here is what is discussed: 1. ELECTRICAL ENERGY, 2. GENERATOR OPERATION, 3. TYPES OF GENERATORS, 4. AC GENERATORS, 5. ALTERNATOR TYPES, 6. DESIGN, 7. CHARACTERISTICS OF GENERATORS, 8. EXCITERS, 9. CHARACTERISTICS OF EXCITERS, 10. FIELD FLASHING, 11. BEARINGS AND LUBRICATION, 12. GENERATOR MAINTENANCE, 13. INSULATION TESTING