1.1 Scope and object

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:

1. general requirements for the electromechanical equipment of small hydroelectric installations;

2. technical specifications for the electromechanical equipment, excluding its dimensioning and standardization;

3. 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.

1.2 Normative references

The following standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication of this standard, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards.

Considering the scope of this guide, it does not cover the initial stage of investigations, that is to say the preliminary study and feasibility study. Neither does it deal with the economic study concerning the supply and demand of energy.

To conclude, the guide does not replace the necessary engineering studies for the selection, design, manufacture, installation and testing of the equipment. It is intended only to make the purchaser aware of the important points and data to be furnished, specified and kept in due consideration in the construction of small hydroelectric plants.

1.3 Nomenclature

See Annex A.

1.4 Methodology

In the interests of clarity, the sequence of the necessary steps for the construction of a small hydroelectric power plant is represented diagrammatically in Figure 1.

It principally covers the preparation of technical specifications, the examination of tenders, the manufacture, and finally the commercial operation and maintenance of equipment.

This sequence also shows the relationship between the different phases and areas of responsibility of all the parties concerned (consulting engineer, chief resident engineer, and users).

If the purchaser does not have in-house engineering capabilities or the services of a consulting engineer he may call for, to facilitate relations with contractors, a “turn-key” supply, or have at least a leading contractor responsible for the supply of all or part of the electromechanical equipment (e.g. the turbine/generator package, or a “water-to-wire” package).