UL 248-6-2019 pdf free download

UL 248-6-2019 pdf free download.Low-Voltage Fuses – Part 6 : Class H Non-Renewable Fuses.
This UL 248-6 applies to Class H Non-Renewable fuses rated 600 A or less and either 250 or 600 V ac. DC ratings are optional.
4 ClassifIcation
Class H Non-Renewable fuses have an interrupting rating of 10,000 A. Both of the voltage ratings 250 V ac and 600 V ac are divided into six body sizes with the maximum current rating in each size as specified in this Part. These fuses are not classified as current limiting. Time-delay ratings are optional.
In Canada, 250 V ac fuses rated 15 — 60 A shall have a low melting point P” (D for time delay) characteristic. See Clauses 6.1 and 9.2.
5 Characteristics
5.2 Voltage rating
For AC, the rating shall be 250 V ac or 600 V ac in accordance with dimensions shown in Figure A and
Figure B.
The DC voltage rating may be different from the AC rating.
5.3 Current rating
Refer to Figure A and Figure B for range of current ratings in each body size for each voltage rating.
5.5 Interrupting rating
For AC — 10,000 A
For DC—10,000A
6 Marking
6.1 Marking of fuses
In addition to the requirements r Part 1: Fuses with a low melting point characteristic, for Canada, shall be marked with a “P” or with a “D for time delay.
g) The fuse shag not be marked TMCurrent limIting.
8.2 Verification of temperature rise and current-carrying capacity
8.2.3 Test method
1.0 I,, — Temperature nse
1.1 l, — 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 I 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:
Contacts — ≤100A—55°C
>100A—75°C
8.3 Verification of overload operation
Pail 1. Table 4
Test I — 1.35 I
Test 3—2
Test 5—5 I for time-delay fuses only. For 250 V ac rated 30 A or less, the clearing time shall be 8 s minimum.UL 248-6-2019 pdf free download.