This Guide describes tests performed and provides processes to be followed during the commissioning of electrical and control systems in hydroelectric plants. Guidance for methods to be used@ organization and execution of the testing are provided. While the guide does not provide prescriptive procedures which are plant and equipment specific@ tests are described along with reference standards for more information. The commissioning of electrical equipment may be for a new hydroelectric plant installation; rehabilitation of an existing hydroelectric plant; or replacement and upgrade of existing electrical equipment.