UL 248-9:2010 pdf download.Low-Voltage Fuses - Part 9:Class K Fuses.
This Part applies to Class K fuses rated 600 A or less and either 250 or 600 V ac. DC ratings are optional. 4 Classification
Class K fuses are non-renewable, with interrupting ratings of 50.000, 100,000, or 200,000 A. Class K fuses are divided into sub-classes K-i, K-5, and K-9 which are physically interchangeable with each other (and Class H fuses) for the same current and voltage ratings. Each sub-class has specified limits of peak let-through current and clearing 12t characteristics. K-i has the lowest limits (most current-limiting), K-5 higher, and K-9 highest. Each of the voltage ratings, 250 and 600 V ac, is divided into six body sizes. The maximum current rating, I, for each size is specified in this Part. Time-delay ratings are optional.
In Canada, 250V ac fuses rated 15 — 60 A shall have a low melting point “P (“D” for time delay) characteristic. See sub-clauses 61 and 9.2.
5 Characteristics
5.2 Voltage rating
For AC. the rating shall be 250 or 600 V ac in accordance with dimensions shown in Figure A. The DC voltage rating may be different from the AC rating.
5.3 Current rating
Refer to Figures A and B for range of current ratings in each body size for each voltage rating.
Class K fuses are non-renewable, with interrupting ratings of 50.000, 100,000, or 200,000 A. Class K fuses are divided into sub-classes K-i, K-5, and K-9 which are physically interchangeable with each other (and Class H fuses) for the same current and voltage ratings. Each sub-class has specified limits of peak let-through current and clearing 12t characteristics. K-i has the lowest limits (most current-limiting), K-5 higher, and K-9 highest. Each of the voltage ratings, 250 and 600 V ac, is divided into six body sizes. The maximum current rating, I, for each size is specified in this Part. Time-delay ratings are optional.
In Canada, 250V ac fuses rated 15 — 60 A shall have a low melting point “P (“D” for time delay) characteristic. See sub-clauses 61 and 9.2.
5 Characteristics
5.2 Voltage rating
For AC. the rating shall be 250 or 600 V ac in accordance with dimensions shown in Figure A. The DC voltage rating may be different from the AC rating.
5.3 Current rating
Refer to Figures A and B for range of current ratings in each body size for each voltage rating.
