ApplicationThis guide covers general recommendations for the operation@ loading@ and maintenance of synchronous hydro-generators and generator/motors. It does not apply to synchronous machines having cylindrical rotors. In this guide@ the term hydro-generator is used to describe a synchronous machine coupled to a hydraulic turbine or pump-turbine. This guide is not intended to apply in any way to the prime mover.Manufacturer??s instructionsThis guide is not intended to supplant specific or general instructions contained in the manufacturer??s instruction book or in any contractual agreement between the manufacturer and the purchaser of a given machine.Limitations due to various designsEquipment manufacturers have taken different approaches to the solution of design requirements; therefore@ it is not practical to relate specifically in this guide to all the variations of machine design. However@ many of the operational and maintenance procedures and problems are common to all the designs and@ therefore@ recommendations are given concerning solutions to these procedures and problems. The most that this document can accomplish is to provide guidelines@ which@ on one hand@ disclose accepted and tried values or methods@ and on the other hand@ give warnings where hazards might be encountered.ExcitersThis guide does not cover in detail associated rotating or stationary excitation systems.