UL 248-12:2000 pdf download.Low-Voltage Fuses - Part 12:Class R Fuses.
8 Tests
8.2 Verification of temperature rise and current-carrying capacity
8.2.3 Test method
1.0 In — Temperature rise
1.1 In — Current-carrying capacity, l
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 In for a period of not less than 15 mm for fuses rated 0 — 200 A and not less than 30 mm for fuses rated 201 — 600 A. Temperature is not to be monitored during this time.
8.2.4 Acceptability of test results
In addition to the requirements in Part 1: The maximum temperature rise shall not exceed the following:
Body — 80°C:
Contacts — 100 A: 55°C; >100 A: 75°C.
8.3 Verification of overload operation
Part 1, Table 4
Test 1 — 1 .35 In
Test 3 — 2.0 In
Test 5 — 5.0 In for time-delay fuses only. For 250 V ac fuses rated 30 A or less, the clearing time may be 8 s minimum.
8.2 Verification of temperature rise and current-carrying capacity
8.2.3 Test method
1.0 In — Temperature rise
1.1 In — Current-carrying capacity, l
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 In for a period of not less than 15 mm for fuses rated 0 — 200 A and not less than 30 mm for fuses rated 201 — 600 A. Temperature is not to be monitored during this time.
8.2.4 Acceptability of test results
In addition to the requirements in Part 1: The maximum temperature rise shall not exceed the following:
Body — 80°C:
Contacts — 100 A: 55°C; >100 A: 75°C.
8.3 Verification of overload operation
Part 1, Table 4
Test 1 — 1 .35 In
Test 3 — 2.0 In
Test 5 — 5.0 In for time-delay fuses only. For 250 V ac fuses rated 30 A or less, the clearing time may be 8 s minimum.
