BS-5584-1978 EN-50022-1977.pdf

british standard bs 5584:1978 en 50 022 specification for low voltage switchgear and controlgear for industrial use mounting rails top hat rails 35 mm wide for snap-on mounting of equipment this european standard en 50 022 was given as from 31 may 1978 the status of a british standard udc 621.316.54:621.3.027.2:62218423.9 bs 5584:1978 this british standard was published under the authority of the executive board on 31 may 1978 bsi 03-1999 the following bsi references relate to the work on this standard: committee reference pel/92 draft for comment 75/21514 dc isbn 0 580 10126 6 cooperating organizations the european committee for electrotechnical standardization (cenelec), under whose supervision this european standard was prepared, comprises the national committees of the following countries. a british standard does not purport to include all the necessary provisions of a contract. users of british standards are responsible for their correct application. compliance with a british standard does not of itself confer immunity from legal obligations. summary of pages this document comprises a front cover, an inside front cover, pages i and ii, the en title page, pages 2 to 8, an inside back cover and a back cover. this standard has been updated (see copyright date) and may have had amendments incorporated. this will be indicated in the amendment table on the inside front cover. austrianetherlands belgiumnorway denmarkportugal finlandspain francesweden germanyswitzerland irelandunited kingdom italy amendments issued since publication amd. no.date of issuecomments bs 5584:1978 bsi 03-1999i contents page cooperating organizationsinside front cover text of en 50 0223 national appendix ainside back cover national appendix binside back cover ii blank european standard norme europenne europische norm en 50 022 edition 1 july 1977 udc 621.316.54:621.3.027.2:62218423.9 key words: electrical switchgear and controlgear industrial use domestic use mounting rail mounting of equipment snap-on mounting top hat rail steel rail dimensional standardization 35 mm wide (top hat rail) english version low voltage switchgear and controlgear for industrial use mounting rails top hat rails 35 mm wide for snap-on mounting of equipment appareillage industriel basse tension. profils supports. profils chapeau de longeur 35 mm pour la fixation dappareils encliquetables industrielle niederspannungs-schaltgerte. tragschienen. hutschienen 35 mm breit zur schnappbesfestigung von gerten this european standard was accepted by cenelec on 5 july 1977. cenelec members are committed in accordance with cenelec internal regulations to given this european standard the status of a national standard without any alteration. up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the cenelec general secretariat or to any cenelec member. this european standard is established by cenelec in three official versions (english, french, german). a translation made by another member under its own responsibility, in its own language, and notified to cenelec has the same status. cenelec members are the national electrotechnical committees of austria, belgium, denmark, finland, france, germany, ireland, italy, netherlands, norway, portugal, spain, sweden, switzerland and united kingdom. cenelec european committee for electrotechnical standardization comit europen de normalisation electrotechnique europisches komitee fr elektrotechnische normung general secretariat: rue brderode, 2, b1000 brussels copyright reserved to all cenelec members en 50 022 bsi 03-1999 2 contents page this european standard has been prepared by cenelec technical committee 17x. 1general3 2scope3 3dimensions3 4designation3 5material3 6finish3 7availability3 8tolerances on form4 appendix guidance for the use of top hat rails5 figure 1 top hat rails 35 mm wide3 figure 2 tolerances on form4 figure 3 assessment of deflection of rail5 figure 4 load capacity, me= f (l, h)6 en 50 022 bsi 03-19993 this european standard has been prepared by cenelec technical committee 17x. 1 general to ensure the universal utilization of snap-on mounting of equipment, it is appropriate to standardize certain types of rail. this standard specifies two types of top hat rail, both 35 mm wide: one, 7.5 mm high, is already widely used; the other, 15 mm high, is new; it is more rigid and permits the mounting of heavier equipment and/or greater distances between fixing points. for the mounting of equipment that is too large or too heavy for either 35 mm top hat rail, a 75 mm top hat rail is specified in en 50 023. 2 scope this standard specifies 35 mm wide steel top hat rails for the snap-on mounting of equipment. 3 dimensions the dimensions of both types of top hat rail are given in figure 1. these dimensions apply over the whole length of the top hat rail, but shall not be verified anywhere less than 10 mm from the ends. 4 designation the designation of a 35 mm wide top hat rail, 7.5 mm high: top hat rail en 50 022 35 7.5 the designation of a 35 mm wide top hat rail, 15 mm high: top hat rail en 50 022 35 15 5 material the material used shall be: cold rolled carbon steel sheet; skin passed after annealing; bright surface finish; tensile strength between 320 n/mm2 and 420 n/mm2; elongation at least 30 %; 180 bend tested longitudinally and transversely with regard to the direction of rolling. each country may indicate its corresponding national standard. other qualities of steel may be used only by agreement between the manufacturer and the user. 6 finish the finish shall be zinc-plated and chromated, with a layer thickness of at least 6 4m, except for cut surfaces resulting from cutting to length. other finishes may be used by agreement between the manufacturer and the user. 7 availability top hat rails shall be supplied either in manufactured lengths of at least 1 m, or in ready cut lengths. figure 1 top hat rails 35 mm wide en 50 022 4 bsi 03-1999 8 tolerances on form the tolerances on form are shown in figure 2, in accordance with iso/r 11011). 1) reference of corresponding national standard (see national appendix b) figure 2 tolerances on form en 50 022 bsi 03-19995 appendix guidance for the use of top hat rails to determine the permissible load of rails, correctly used, the twisting deformation is always the most important factor. the sagging stress, on the other hand, is small and can be disregarded. research has shown that, as a result of the current practice of fixing rails by means of two screws, a torsion stress 50 n/mm2 can cause a permanent deformation of the rail. the maximum permissible torque for that stress is independent of the distance between rail fixing points, e.g. 750 n mm for a top hat rail 35 7.5. for distances between fixing points used in practice, with this force an excessive deformation occurs generally in the middle of the top hat rail. a method for assessing this deformation is shown in figure 3. using this method, the maximum equivalent torque me as a function of the distance l between fixing points has been calculated for three values of deflection h, for both types of rail and is shown in figure 4. mis the torque due to the force from the equipment mounted on the rail, which equals force times the distance between the centre of gravity and the mounting plane (in n mm) (possibly supplemented to take shocks into account) meis the moment (in n mm) of the equivalent torque acting in the middle of the rail for a number of individual moments m of similar equipment: jp is the polar moment of inertia of the rail (in mm4) g is the sliding modulus (steel plate 80 000 n/mm2) lis the distance between fixing points (in mm) his the deflection (in mm) of the rail at 50 mm from the fixing surface of the equipment: figure 3 assessment of deflection of rail m e = cm 2 - h me.l 4.jp.g - - 50= en 50 022 6 bsi 03-1999 figure 4 load capacity, me= f (l, h) en 50 022 bsi 03-19997 example 1. a rail 35 7.5, l = 300 mm, may be loaded with me= 350 n mm for h = 1 mm. example 2. it is required to use a rail 800 mm long to support equipment having an equivalent torque me= 480 n mm for h = 1 mm. 1st possibility: rail 35 15 figure 4 shows that l = 800 mm is convenient for mek 2 100 n mm 2nd possibility: rail 35 7.5 figure 4 shows that l = 800 mm is only acceptable with mek 120 n mm, and that l = 400 mm could be acceptable, since mek 250 n mm. as 250 n mm 480/2 n mm, an intermediate fixing point at l = 400 mm would be sufficient. 8 blank bs 5584:1978 bsi 03-1999 national appendix a the united kingdom participation in the preparation of this european standard came under the direction of the power electrical engineering standards committee of bsi. the committee consists of representatives from the following government departments and scientific and industrial organizations: associated offices technical committee association of short circuit testing authorities* british electrical and allied manufacturers association (beama)* british railways board british steel corporation department of energy (electricity) electrical contractors association* electrical contractors association of scotland* electrical research association* electricity supply industry in england and wales* engineering equipment users association* institution of electrical engineers* ministry of defence* national coal board* trades union congress the organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee involved with the work on this standard: association of control manufacturers (beama) association of supervisory and executive engineers control and automation manufacturers association (beama) copper development association department of the environment (psa) electrical installation equipment manufacturers association (beama) electronic components industry federation health and safety executive the transmission & distribution association (beama) national appendix b with reference to clause 1, en 50 022 has been published as bs 5584 “specification for low voltage switchgear and controlgear for industrial use. mounting rails. top hat rails 35 mm wide for snap-on mounting of equipment”. with reference to clause 8, bs 308 “engineering drawing practice” is technically equivalent to iso/r 1101. bsi 389 chiswick high road london w4 4al | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bsi british standards institution bsi is the independent national body responsible for preparing british standards. it presents the uk view on standards in europe and at the international level. it is incorporated by royal charter. revisions british standards are updated by amendment or revision. users of british 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