This International Standard is used as a guide that applies to hydroelectric installations with units having power outputs less than 5 MW and turbines with nominal runner diameters less than 3 m. These figures do not represent absolute limits. This guide deals only with the direct relations between the purchaser or the consulting engineer and the supplier. It does not deal with civil works, administrative conditions or commercial conditions. This guide is intended to be used by all concerned in the installation of electromechanical equipment for small hydroelectric plants. This guide, based essentially on practical information, aims specifically at supplying the purchaser of the equipment with information which will assist him with the following: - preparation of the call for tenders; - evaluation of the tenders; - contact with the supplier during the design and manufacture of equipment; - quality control during the manufacture and shop-testing; - follow-up of site erection; - commissioning; - acceptance tests; - operation and maintenance. The guide comprises the following: a) general requirements for the electromechanical equipment of small hydroelectric installations; b) technical specifications for the electromechanical equipment, excluding its dimensioning and standardization; c) requirements for acceptance, operation and maintenance. Bearing in mind the type of installation considered, the documents shall be as simple as possible but must satisfactorily define the particular operation conditions. Over-specification is harmful to the economy of the project.