IEC 60269-3-2015 pdf free download.Low-voltage fuses – Part 3: Supplementary requirements for fuses for use by unskilled persons (fuses mainly for household and similar applications) – Examples of standardized systems of fuses A to F.
The fuse is placed in a test arrangement according to Figure 107 and placed in a heating chamber, the holes provided for the passage of conductors are sealed. The length of the connected conductors shall be at least 1 m outside the heating chamber. The heating chamber must be such that during the test, the air temperature is kept at 80 °C ± 5 C, measured in the plane of the sample at a distance of approximately 15 cm.
8.9.1.2 Test method
The air temperature in the heating chamber is raised to 80 °C ± 5 C and is maintained for 2 h. Immediately afterwards, but while maintaining the temperature of the heating chamber, the sample is loaded with a test current corresponding to approximately I. At this test current the power dissipation of the dummy fuse-link shall lie within the limits indicated in Table 114. The current shall be kept constant during the whole test duration of 2 h. At the end of the test, a weight is applied straight and not jerkily at position 4 (see Figure 107), which (taking into account the lever-arm relations) generates along arrow G a force according to Table 114 on the dummy fuse-link. To apply the force, the inspection window has to be removed. The sample may be connected to a reduced voltage source (42 V).
8.9.1.3 Acceptability of test results
After applying the force, a current shall continue to flow through the sample. The force is maintained for 15 mm and the current shall continue to flow unchanged through the sample. Furthermore, after this test, the fuse-base shall not show any damage impairing its further use.
8.9.2 Fuse-carrier
8.9.2.1 Test arrangement
A fuse-base shall be mounted on a 15 mm thick plywood board. The arrangement shall be the
same as in normal use. The fuse-base is fitted with a dummy fuse-link according to Figure
104. The cross-sectional area of conductors depends on the rated current of the fuse-base
(see IEC 60269-1, Table 17). The length of the conductors shalt be at ‘east I m outside the
heating chamber in which the test arrangement is to be placed.
The torque applied to the fuse-carrier shall correspond to Table 115. For tightening and later loosening of the fuse-carrier, an adapter for the fuse-carrier is used, the interior form of which enables a tight connection to the insulated part of the fuse-carrier. The adapter of the fusecarrier is tightened with a torque wrench with a square-section shank — as is usual in service — (see Figure 108). The nut and the described test device shall be placed in the abovementioned heating chamber.IEC 60269-3 pdf download.