IEC 60282-1-2020 pdf free download – High-voltage fuses – Part 1: Current-limiting fuses (IEC 60282-1:2020).
5.2.2Rated current of a fuse-base
The current assigned to a fuse-base that a new clean fuse-base will carry continuouslywithout exceeding specified temperature rises under prescribed conditions. These conditionsare that the fuse-base is equipped with a fuse-link designed to be used in the particular fuse-base,that the fuse-link has a rated current the same as the rated current of the fuse base,that the fuse-base is connected to the circuit with conductors of certain specified sizes andlengths, and that the ambient air temperature is not more than 40 °c.
The rated current of a fuse-base should be selected from the following values:
10 A; 25 A;63 A; 100 A; 200 A; 400 A; 630 A; 1 000 A.
5.2.3Rated current of a fuse-link (I,)
The current assigned to a fuse-link that a new clean fuse-link will carry continuously withoutexceeding specified temperature rises when mounted on a fuse-base specified by themanufacturer and connected to the circuit with certain specified conductor sizes and lengths,at an ambient air temperature of not more than 40 °C (see lEC TR 62655:2013).
The rated current in amperes of the fuse-link should be selected from the R10 series. Forspecial cases,additional values for the rated current of the fuse-link may be selected from theR20 series.
NOTEThe R10 series comprises the numbers 1;1,25;， 1,6;2;2,5; 3,15; 4; 5; 6,3;8 and their multiples of 10.The R20 series comprises the numbers 1;1,12;1,25;1,40;1,6;1,8;2;2,24;2,5;2,8;3,15;3,55;4; 4,5; 5;5,6;6,3;7,1;8; 9 and their multiples of 10.
5.2.4Rated insulation level (of a fuse-base)
The voltage values (both power frequency and impulse) that characterise the insulation of afuse-basewith regardto itscapability ‘ of ‘withstandingdielectric stresses(see IEC TR 62655:2013，4.5) under normal service conditions defined in 4.1 includingaltitudes from sea level up to i ooo m.
Two levels of dielectric withstand are recognised for a fuse-base according to Europeanpractice.These are termed “List 1” and “List 2” and relate to different severities of applicationand corresponding different values oftest voltage for the dielectric tests(see lEC TR 62655:2013,4.5.2).
The rated insulation level of a fuse-base should be selected from Table 4 and Table 5.
Table 4 is based on practice in Europe, and standard reference conditions of temperature,pressure and humidity are 20 °C,101,3 kPa and 11 g/m3, respectively, of water.
Table 5 is based on practice in the USA and Canada where standard reference conditionsof temperature, pressure and humidity are 25 “C,101,3 kPa and 15 g/m3, respectively, ofwater.
lt shall be stated whether the fuse is suitable for indoor or outdoor service.
5.2.5 Rated breaking capacity
5.2.5.1 Rated maximum breaking current (1,)
The rated maximum breaking current in kA of a fuse-link should be selected from the R10series.
NOTE The R10 series comprises the numbers 1;1.25; 1,6;2; 2,5; 3.15;4; 5; 6,3;8 and their multiples of 10.5.2.5.2Rated minimum breaking current and class
The manufacturer shall indicate the class (see 3.3.2) and，for Back-Up fuses，the ratedminimum breaking current. In the case of General-Purpose fuses，the minimum breakingcurrent may also be indicated.
5.2.6Rated frequency
Standard values of rated frequency are 50 Hz and 60 Hz. lt should be noted that fuses arenormally tested at either 50 Hz or 60 Hz.However,experience has shown that,while thesame fuse design tested at both frequencies at a current that produces a current-limitingaction generally exhibits slightly higher peak currents at 60 Hz and slightly higheroperating 2t values at 50 Hz, fuses successfully passing all testing at one frequency aresuitable for use at the other frequency.
5.2.7Temperature limits
5.2.7.1surrounding temperature of 40 c or less
A fuse-link and a fuse-base shall be able to carry their rated current continuously withoutexceeding the limits of temperature rise (above ambient temperature) given in Table 6, andwithout deterioration.IEC 60282-1 pdf download.