Confidence — Low-voltage Power switchgear and controlgear assemblies PSC-Assemblies , by the nature of their application, may be installed for many years before they are called on to operate close to the limit of their intended capability, for example, under planned expansion or fault conditions. As a result, any marginal performance may not be immediately evident. With a verified PSC Assembly concerns of this nature are eliminated. The design is proven through a comprehensive design verification process which includes tests or other equivalent means. Where methods other than test are used, margins are included to ensure the specified performance is achieved. This is an essential assurance for user confidence.
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Aralkree NOTE If components, for example relays, electronic equipment, are used which are not designed for these conditions, appropriate steps should be taken to ensure proper operation.
Together with BS EN In particular, the effects of thermal expansion and of the electrolytic action in the case of dissimilar metals, and the effects of the endurance of the materials to the temperatures attained, shall be taken into consideration. E tests have been performed on the lifting beams that manufacture; these can be reviewed during CFAT and prior to despatch. Any designations used shall be in compliance with IEC and IEC and identical with those used in the wiring diagrams, which shall be in accordance with IEC This list is not exhaustive; additional Parts may be developed as the need arises.
The test specimens shall be new and in a clean condition and shall be subjected to severity test A or B, as detailed in For each representative outgoing unit, a separate test shall be made with a bolted short-circuit connection between the corresponding outgoing phase terminal of the unit and the terminal for the relevant outgoing protective conductor. Deformation of parts of the enclosure or of the internal partitions, barriers and obstacles due to a short-circuit shall not reduce permanently the clearances or creepage distances below those specified in 8.
Enclosure temperatures shall not exceed the values given in Table 6. General be — IEC The requirements to be complied with are given in the following subclauses. BS EN Protection for safety — Protection against voltage disturbances and electromagnetic disturbances IEC Electrical installations of buildings — — — Part NOTE 2 The maximum load currents are used for the calculation instead of the rated currents of the circuits and the rated diversity factor because these two rated values need more detailed consideration of different load conditions.
RevisionsInformation on standardsBritish Standards are updated by amendment or revision. The rated diversity factor confirms the per unit value of rated current to which all the outgoing circuits, or a group of outgoing circuits, within the ASSEMBLY, can be continuously and simultaneously loaded.
Earth continuity shall be in accordance with 8. Natural circulation may be provided by holes in the walls of the cabinet. Information regarding online access to British Standards via BritishIn addition all orders b BSI, international bz foreign standards publicationsStandards Online can be found at www.
Ratio of cross section of the neutral conductor to phase 8. Use of this product in environment B may cause unwanted electromagnetic disturbances in which case the user may be required to take adequate mitigation measures. Introduction to Blackburn Starling To verify the rated diversity factor one additional test with simultaneous load on all circuits has to be done. Thus to verify the rated currents of all circuits a separate test for each type of circuit is necessary.
For the electrical conditions associated with the different positions of withdrawable parts, see Table Verification of the actual temperature rise under these conditions shall be determined by test. Gap between head of screw and wall of Rule: During the test, with the test weights in place, the ASSEMBLY shall show no deflections and after the test show no cracks or permanent —1 visible to normal or corrected vision without additional magnification, which could impair any of its characteristics.
As an alternative the original manufacturer shall provide data on the suitability of materials from the insulating material supplier to demonstrate be with the requirements of 8. The original manufacturer shall determine all relevant items of the test, such as type of supply, number of phases and frequency where applicablecross-sections of test conductors, etc.
NOTE Conductors which are connected to a functional unit but where they are external to its compartment or enclosed protected space e. Compliance is checked according to the test of Switchgear, controlgear and fuses IEC Rated diversity factor can be stated: In the run of protective conductors links shall be permitted which are removable by means of a tool and accessible only to authorized personnel these links may be required for certain tests.
Introduction to Separation of terminals for external Terminals for external conductors not in the Form 4b conductors associated with a functional unit from same compartment as the associated functional those of any other functional unit and the unit, but in individual, separate, enclosed busbars. Sheathed cables for fixed wiring IEC For the verification of all the short-circuit withstand ratings see 5. For functional units with several devices, it is that of the device with the lowest rated current.
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BS EN 61439-2:2011