EN IEC 60230 pdf download

EN IEC 60230 pdf download.IMPULSE TESTS ON CABLES AND THEIR ACCESSORIES
1 Scope
This document defines the procedure for carrying out withstand lightning and switching impulse tests and withstand superimposed impulse test on cables and their accessories. This document applies solely to the methods of carrying out the tests as such, independently of the problem of selecting the test levels to be specified. The voltages pertaining to the system on which cables and accessories are to be used are given in IEC 601 83 or in the relevant product standard. This document specifies the following requirements: • the characteristics and state of the test installation and those parts of the procedure which are common to withstand tests and tests above the withstand level; • the procedure for carrying out withstand lightning and switching impulse tests and superimposed impulse test; • the procedure for carrying out tests above the withstand level which is intended for research purposes.
3 Terms and definitions
For the purposes of this document, the terms and definitions given in the relevant product standards and the following apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp 3.1 superimposed impulse voltage impulse voltage applied to a test object which is at the same time energized by a DC voltage Note 1 to entry: The superimposed impulse voltage falls under the definition of composite voltage given in IEC 60060-1 :201 0, 9.2.
4 Characteristics of the test object to be subjected to the tests
The test object shall have been previously subjected to the test protocol as required by the relevant IEC product standards.If not specified in the reference IEC product standards, the following conditions shall be maintained: • If the test object is not intended to include any other accessory, the length of the sample taken shall be such that the length of free cable between the terminations is at least 5 m. • Where one joint is included in the test object, the minimum length of free cable, between the joint and terminations shall be 5 m. Where more than one joint is included, the same requirement shall be observed and in addition there shall be a minimum length of 3 m of free cable between successive joints.
5 State of the test object to be subjected to the test
The test object shall be maintained under the following conditions. • Pressure conditions, if any: For gas-pressure and oil-filled cables, the pressure shall be adjusted in accordance with the relevant IEC standard. • Temperature conditions: The temperature conditions and the method of temperature measurement shall be as described in the relevant IEC standard, but other methods of temperature measurement may be used by agreement between the purchaser and the manufacturer.
8 Superimposed impulse voltage test
8.1 General The superimposed impulse voltage test shall be carried out on HVDC cable systems. The peak voltage level of the switching impulse is specified in the relevant product standard. When a superimposed impulse voltage test is required, Clause 8 shall be applied in addition to the other clauses of this document. 8.2 Test setup Some possibilities are given to apply an impulse voltage to a test object which is at the same time energized by a DC voltage; Annex C illustrates the possible superimposed impulse test circuit arrangements.8.3 Time parameters The time parameters shall meet the requirements of Clause 6 or Clause 7 and shall be determined with the DC voltage source set to zero output or disconnected, i.e. without energizing the test object by a DC voltage and with the spark gap (as applicable) short-circuited. Once the time parameters have been determined, there shall be no changes to the test setup other than connecting the DC voltage source and removing the short-circuit across the spark gap. The time parameters are to be determined in this way because a base level around 0 kV is required by IEC 60060-1 . 8.4 Application of the DC voltage Before the impulses are applied to the test object, if required, the test object shall be energized by a DC voltage with a level and duration and polarity as specified in the product standard. The application of the impulses is given in Clause 1 0.