DIN EN 60127-3:2015-11

This part of IEC 60127-3 is applicable to sub-miniature fuse-links adapted to printed circuits and used for the protection of electric appliances, electronic equipment and component parts thereof, normally intended to be used indoors. It does not apply to sub-miniature fuse-links for appliances intended to be used under special conditions, such as in a corrosive or explosive atmosphere. This standard applies in addition to the requirements of IEC 60127-1. The object of this standard is to define special and additional test methods for sub-miniature fuse-links applying in addition to the requirements of IEC 60127-1. Sub-miniature fuse-links according to standard sheets 3 and 4 may be provided with markings for the rated current, the rated voltage and the time/current characteristic on the top so that they are visible when the fuse-link is mounted. Where marking is impractical due to space limitations, the relevant information should appear on the smallest package and in the manufacturer's technical literature. For testing individual fuse ratings according to standard sheets 1 and 2, the number of sub-miniature fuse-links required is 66, of which 12 are kept as spares, for testing individual fuse ratings according to standard sheets 3 and 4, the number of fuse-links required is 51, of which 12 are kept as spares. For the maximum ampere rating of a homogeneous series, the number of fuse-links required in the case of fuse-links in accordance with standard sheets 1 and 2 is 56, of which 22 are kept as spares, the number of fuse-links required in the case of fuse-links in accordance with standard sheets 3 and 4 is 51, of which 22 are kept as spares. For the minimum ampere rating of a homogeneous series the number of fuse-links required is 38, of which 16 are kept as spares. Fuse-links shall be mounted upon the appropriate test board by soldering. This test board shall then be mounted on the test fuse-base. The test board shall be made of epoxide woven glass fabric copper-clad laminated sheet, as defined in IEC 61249-2-7. The sub-miniature fuse-link shall be resistant to heat according to 9.7 of IEC 60127-1, and to fire in accordance with IEC 60695-11-5 (needle-flame test). The sub-miniature fuse-link terminations should be firmly attached so that it is not possible to remove them without damaging the sub-miniature fuse-link. Terminations shall withstand the mechanical forces likely to be encountered during normal use. With the sub-miniature fuse-link held in a fixed position, each terminal in turn is subjected at ambient temperature to the forces laid down in this standard. These forces shall be exerted in the direction of the axis of the terminal and applied progressively without jerks. Test sample groups shall be equally divided among the specific termination tests stipulated in the relevant standard sheets. Electrical requirements, such as voltage drop and breaking capacity according to IEC 60127-1, are supplemented with further requirements in this standard. The sub-miniature fuse-link shall switch off properly during each test without any phenomena such as melting of the contacts or connections, illegibility of the label after the test or holes on the outer surface, as far as these can be seen with the naked eye. The appearance of black spots on the terminations of the sub-miniature fuse-link, slight deformation of the terminations of the sub-miniature fuse-link and cracks in the sub-miniature fuse-link are not subjected to. In the endurance test at normal ambient temperature, compliance is verified by subjecting the sub-miniature fuse-links to test method A or B, as specified in the relevant standard sheets. The temperature of the fuse-links is tested according to IEC 60127-1 with the following modifications. The temperature rise shall not exceed 150 K when measured on the terminations where they enter the test board, and 135 K when measured on the plastic fuse body. Table 1 - Testing schedule for individual ampere ratings, standard sheets 1 and 2. Table 2 - Testing schedule for individual rated currents, standard sheets 3 and 4. Table 3 - Testing schedule for the highest rated current of a homogeneous series, standard sheets 1 and 2. Table 4 - Testing schedule for the highest rated current of a homogeneous series, standard sheets 3 and Table 5 - Testing schedule for the lowest rated current of a homogeneous series, standard sheets 1 to 4. The standard sheets 1 - 3 listed in Clause 10 describe sub-miniature fuse-links, fast-acting, small breaking capacity, standard sheet 4 describes small fuse-links, slow, small breaking capacity. The responsible body is DKE/K 663 "Gerätesicherungen (G-Sicherungen)" of the DKE (German Commission for Electrical, Electronic and Information Technologies) at DIN and VDE.