UL 248-16:2018-04 Low-Voltage Fuses一Part 16: Test Limiters.
This Part applies to test limiters calibrated to specific limits of peak let-through current and clearing 12t at
250, 300, 480, or 600 V ac.
4 Classification
Test limiters are non-renewable and current limiting, with test current ratings up to 200,000 A. They are calibrated to maximum peak let-through current and clearing l2t limits for the fuses specified in this Standard and are used for withstand testing of equipment designed to accept those fuses. Body sizes are not specified.
5 Characteristics
5.2 Voltage rating
For AC, the rating shall be 250, 300, 480, or 600 V ac.
5.3 Current rating
No current rating is assigned to a test limiter except in reference to (and marked as) the ampere rating for the fuse and classification it represents.
5.5 Interrupting rating
No interrupting rating is assigned to a test limiter. Instead a test current rating is assigned. See test current rating, Clause 5.7.
5.6 Peak let-through current and clearing 12t characteristics
Values of peak let-through current and clearing 12t at rated voltage for each test limiter shall be equal to or greater than the maximum values which correspond to the voltage, ampere rating, and classification of the fuse it represents, when tested at its assigned test current rating.
5.7 Test current rating
For AC — 200,000 A, unless otherwise specified.
6 Marking
6.1 Marking of fuses
A test limiter shall be marked with the fuse class it represents, ampere and voltage rating, assigned test
current rating, and the words “THIS IS NOT A FUSE.” For example, “Class J Test Limiter; 30 A, 600 V;
200,000 A; THIS IS NOT A FUSE.”
7 Construction
7.1 Dimensions
Test limiter dimensions are not specified.
8 Tests
8.4 Verification of operation at rated voltage
8.4.3 Test method
Test limiters shall be tested at rated voltage, rated test current for verification of peak let-through current, and clearing 12t.
Two samples of each rating shall be tested.UL 248-16 pdf download.