UL 248-10:2017-01 Low-Voltage Fuses – Part 10: Class L Fuses

UL 248-10:2017-01 Low-Voltage Fuses – Part 10: Class L Fuses. This Part applies to Class L fuses rated 100 — 6000 A and 600 V ac. DC ratings are optional. 4 Classification Class L fuses are non-renewable, current-limiting bolt-in type with an interrupting rating of 200,000 A, or at the manufacturer’s option 300,000 A. Class L fuses are divided into nine body sizes with the maximum current rating I for each size specified in this part. Time-delay ratings are optional. 5 Characteristics 5.2 Voltage rating For AC, the rating shall be 600 V ac. The DC voltage rating may be different from the AC rating. 5.3 Current rating Refer to Figure A for the range of current ratings in each body size. 5.5 Interrupting rating For AC, 200,000 A or 300,000 A at the manufacturer’s option (300,000 A not applicable in Mexico). For DC, the preferred ratings are 20,000, 50,000, 100,000, 150,000, 200,000, or 300,000 A. 8.2.4 Acceptability of test results The maximum temperature rise above the calibration temperature rise of the test equipment shall not exceed 65°C. 8.3 Verification of overload operation Part 1, Table 4 Test 2— 1.5 In 8.3.3.2 Time delay test There is no specified test for time delay. 8.4 Verification of operation at rated voltage For AC — Part 1, Table 5 Test 1 — 200 kA or 300 kA at the manufacturer’s option. Test 2 — Maximum energy Test 3 — Threshold ratio; the maximum threshold ratio shall be: a) 30 for 100 — 1200 A; b) 35 for 1201 — 2000 A; C) 40 for 2001 — 4000 A; and d) Ratio not applicable above 4000 A. Test 4a — 100 kA Test 4b — 50 kA Peak let-through current and clearing 12t recorded during test 1, 4a, and 4b. For DC (optional) — Part 1, Table 6 Test 1 — Interrupting rating Test 5b — 3.0. l, or Test 5c — 2.0 I,, or any current in the range of 2.0 I, — 3.0 I, at rated DC voltage.UL 248-10 pdf download.