8 Electrical apparatus 8.1 Voltage source The test voltage applied to the electrodes shall be provided by a power supply having the following characteristics and components. A choice of voltage of either positive or negative polarity shall be provided, one of the connections to the electrodes being earthed. The voltage ripple on the test voltage shall not exceed 2 % of the voltage at all values greater than 50 % of the breakdown voltage. The test voltage shall also be free from transients or other fluctuations exceeding 1 % of the applied voltage. When testing test specimens of low capacitance,...

1 Scope This International Standard lays down uniform rules for the calculation of the effective parameters of closed circuits of ferromagnetic material. 2 Basic rules The following basic rules are applicable to this standard. 2.1 All results shall be expressed in units based on the millimetre, shall be accurate to three significant figures, but to derive l e , A e , and V e the values of C 1 and C 2 shall be calculated to five significant figures. All angles are in radians. NOTE The purpose of specifying this degree of accuracy is only to ensure that parameters...

The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports， Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non- governmental organizations liaising with the...

4.3.1 General The following details apply: a) Length and profile of route. b) Details of laying arrangements (e.g. flat or trefoil arrangement) and how the metallic coverings are connected to each other and to earth. c) Special laying conditions, for example cables in water. Individual installations require special consideration. 4.3.2 Underground cables The following details apply: a) Typical ambient temperatures over the year (see IEC 60287-3-1). b) Details of installation conditions (e.g. direct burial, in ducts, mechanical laying, etc.) to enable decisions to be taken on composition of metallic screen or sheath, type of armour (if required) and type of...

The nominated person in control of the electrical installation and the nominated person in control of the work activity shall agree both the arrangements of the electrical system to allow the work to take place and a description of the work activity on, with or near the electrical installation before any changes to the arrangements of the electrical installation are made or work takes place. The nominated person in control of the electrical installation and the nominated person in control of the work activity can be one and the same person. Where this is the case any permit to work,...

4.1.3 Initial measurements The specimens shall be visually examined and, if required by the relevant specification, electrically and mechanically checked. 4.1.4 Accelerated ageing If accelerated ageing is required by the relevant specification, one of the following procedures shall be adopted. At the end of the conditioning, the specimen shall be subjected to standard atmospheric conditions for testing for not less than 2 h and not more than 24 h. NOTE Terminations may be detached if the ageing temperature is higher than the component’s maximum operating or storage temperature, or if the component is likely to degrade considerably at 100。C in...

902-01-01 conformity assessment demonstration that specified requirements relating to a product, process, system, person or body are fulilled Note 1 to entry: The subject field of conformity assessment includes activities defined elsewhere in ISO/IEC 17000, such as testing, inspection and certification, as well as the accreditation of conformity assessment bodies. Note 2 to entry: The expression “object of conformity assessment” or “object” is used in ISO/IEC 17000 to encompass any particular material, product, installation, process, system, person or body to which conformity assessment is applied. A service is covered by the definition of a product (see Note 1 to 902-02-03)....

The values of nominal voltage (or highest voltage for equipment) specified in this standard are mainly based on the historical development of electrical supply systems throughout the world, since these values turned out to be the most common ones, and have achieved worldwide recognition; The voltage ranges mentioned in this standard have been recognized to be the most appropriate ones as a basis for design and testing of electrical equipment and systems. NOTE 2 It is nevertheless the task of system and product standards to define appropriate testing values, testing conditions and acceptance criteria. 2 Normative references The following referenced...

4 Degrees of protection – First characteristic numeral 4.1 Indication of degree of protection The first characteristic numeral indicates the degree of protection provided by the enclosure to persons and to the parts of the machine inside the enclosure. Table 2 gives, in the third colum, brief details of objects which will be ‘excluded’ from the enclosure for each of the degrees of protection represented by the first characteristic numeral. The term excluded’ implies that a part of the body, a tool or a wire held by a person, either will not enter the machine or, if it enters, that...

7 Protection against effect of lightning 7.1 Installation supplied from a microgrid The overvoltage protection, where necessary, is provided on the microgrid side. 7.2 Standalone installation If the distance between the external generator and the user’s installation is less than 15 m: no special measure is required. If the distance between the external generator and the user’s installation is greater than 15 m and the number of thunderstorm days per year (obtained from iso-keraunic maps) is high (generally more than 25 days per year), a conductor made of bare copper with a sectional area of at least 10 mm2 shall...