UL 248-5-2010 pdf download

UL 248-5-2010 pdf download.Low-Voltage Fuses – Part 5: Class G Fuses.
1 General NOTE – This Part is intended to be read together with the Standard for Low-Voltage Fuses – Part 1 : General Requirements, hereafter referred to as Part 1 . The numbering of the Clauses in this Part correspond to like numbered Clauses in Part 1 . The requirements of Part 1 apply unless modified by this Part. For Clauses not shown below, refer to the Standard for Low-Voltage Fuses – Part 1 : General Requirements, NMX-J-009/248/5-2000-ANCE ♦ CAN/CSA C22.2 No. 248.1 ♦ UL 248-1 . 1.1 Scope This Part applies to Class G fuses rated 20 A or less, 600 V ac; 21 – 60 A, 480 V ac. DC ratings are optional. 4 Classification Class G fuses are non-renewable and current limiting, with an interrupting rating of 1 00,000 A. Class G fuses are divided into four body sizes. The maximum current rating, I n , for each size is specified in this Part. Time-delay ratings are optional. 5 Characteristics 5.2 Voltage rating For AC, the rating shall be 600 V ac for the 0 – 20 A body sizes, and 480 V ac for the 21 – 60 A body sizes. The DC voltage rating may be different from the AC rating. 5.3 Current rating Refer to Figure A for range of current ratings in each body size. 5.5 Interrupting rating For AC – 1 00,000 A For DC, the preferred ratings are 1 0,000, 20,000, 50,000, or 1 00,000 A.
8 Tests 8.2 Verification of temperature rise and current-carrying capacity 8.2.3 Test Method 1 .0 I n – Temperature rise 1 .1 I n – Current-carrying capacity, I nf 8.2.3.1 Fuses rated 600 A or less In addition to the requirements in Part 1 : At the conclusion of the temperature rise test, the test current shall be increased without interruption to 1 .1 I n for a period of not less than 1 5 min. Temperature is not to be monitored during this time. 8.2.4 Acceptability of test results The maximum temperature rise shall not exceed the following: Contacts – 75°C 8.3 Verification of overload operation Part 1 , Table 4 Test 1 – 1 .35 I n Test 3 – 2 I n Test 4 – 2 I n for time delay only (can be combined with Test 3) 8.4 Verification of operation at rated voltage For AC – Part 1 , Table 5 Test 2 – Maximum energy Test 3 – Threshold ratio. The maximum threshold ratio shall be 60. Test 4a – 1 00 kA Test 5b – 2 I n Peak let-through current and clearing I 2 t recorded during Test 4a. For DC – Part 1 , Table 6 Test 1 – Interrupting rating Test 2 – Maximum energyTest 5a – 9 I n for time delay only Test 5c – 2 I n 8.5 Verification of peak let-through current and clearing I 2 t characteristics 8.5.3 Acceptability of test results Peak let-through current and clearing I 2 t values recorded shall not exceed the limits specified in Table A.UL 248-5-2010 pdf download.