UL 248-5-2019 pdf free download

UL 248-5-2019 pdf free download.LoW-Voltage Fuses – Part 5 : Class G Fuses.
This UL 248-5 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 100,000 A. Class G fuses are divided into four body sizes. The maximum current rating, I, for each size is specified in this Part, lime-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, arid 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 ureA for range of current ratings in each body size.
5.5 Interrupting rating
ForAC— 100.000 A
For DC, the preferred ratings are 10,000, 20,000, 50,000, or 100,000 A.
5.6 Peak let-through current and clearing l2t characteristics
Maximum values of peak let-through current and clearing I2t at 100,000 A are given in Table A.
8 Tests
8.2 Verification of temperature rise and current-carrying capacity
8.2.3 Test Method
1.0 l — Temperature rise
1.1 I — Current-carrying capacity,
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 for a period of not less than 15 mm. 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 In
Test 3—2 I
Test 4—2 I 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 — 100 kA
Test5b—2l
Peak let-through current and clearing l2t recorded during Test 4a.
For DC — Part 1, Table 6
Test 1 — Interrupting rating
Test 2 — Maximum energy
Test 5a — 9 l, for time delay only
NMX-J-009i2485-20O0.ANCE . CANICSA-C22.2 No.
JULY 31,2019 248.5.00. UL 24.8.5
Test5c—2I
8.5 Verification of peak let-through current and clearing l2t characteristics
8.5.3 Acceptability of test results
Peak let-through current and dearing l2t values recorded shall not exceed the limits specified in Table A.UL 248-5-2019 pdf free download.