UL 60939-3-2017 pdf download

UL 60939-3-2017 pdf download.Passive Filter Units for Electromagnetic Interference Suppression – Part 3: Passive Filter Units for Which Safety Tests are Appropriate.
4.12 Resistance to soldering heat
412.1 Applicability of the test
This test is not applicable to filters with flexible Insulated leads longer than 50 mm, or to filters with terminations (such as snap-on contacts) not intended to be soldered.
4.12.2 Pro-measurement
The measurements proscribed in the relevant specification shall be made.
4,12.3 Test conditions
There shall be no pre-drying.
4.12.4 Test severity
The filters shall undergo Test Tb of IEC 60068-2-2Owith the following requirements:
a) for
filters designed for use on printed boards, and for filters not designed for use on printed boards, but with leads longer than 4 mm. as indicated in the detail specification, Method 1 shall be used with a temperature of (260 3) dC and a duration of (5 ± 0.5) s or (10 ± 1)s, as specified in the detail specification. The depth of immersion from the seating plane shall be 2.0 mm to 2,5 mm, using a thermal insulating screen of 1,5 mm ± 0,5 mm thickness;
Duration shall be specified in the detail specification.
b) for other filters Method 2 shall be used. The relevant specification shall specify. which soldering iron bit size shall be used.
The period of recovery shall be not less than 1 h and not more than 2 h. unless otherwise specified by the detail specification.
4.12.5 Intermediate inspection, measurements and requirements
The measurements after this test are the intermediate measurements after the tests of Group 1 A and before the remainder of the tests of Group 1.
The filters shall be visually examined according to 4.2. There shall be no VISJBLE DAMAGE.
The d.c. line resistance or voltage drop shall be measured according to 4.9. The value shall be within the limit prescribed in Group A2 of the detail specification.
4.18.4 Damp heat, cyclic
The filters shall be subjected to the test described in Clause 4, severity b) of IEC 60068-2-30:2005 for one cycle of 24 h. Unless variant 1 is prescribed in the relevant specification, variant 2 shall be used.
After recovery the filters shall be subjected immediately to the cold test.
4.18.5 Cold
The filters shall be subjected to Test Ab of IEC 60068-2-1 for 16 h, using the degree of severity of the LOWER CATEGORY TEMPERATURE as prescribed in the relevant specification.
While still at the specified low temperature and at the end of the period of low temperature, the measurements prescribed in the relevant specification shall be made.
After conditioning, the filters shall be removed from the chamber and exposed to standard atmospheric conditions for testing for not less than 4 h.
No measurements are required at the LOWER CATEGORY TEMPERATURE.
4.18.6 Low air pressure
This test is only performed if required in the detail specification. It is not normally specified for MAINS FILTERS.
The filters shall be subjected to Test M of lEO 60068-2-13 using the appropriate degree of severity prescribed in the relevant specification. The duration of the test shall be 10 mm, unless otherwise prescribed in the relevant specification.
The test shall be made at a temperature of 15 °C to 35 °C and a pressure of 8 kPa, unless otherwise specified in the detail specification.
For filters with a rated voltage exceeding 200 V while at the specified low pressure, the rated voltage shall be applied to terminations as prescribed in the relevant specification for the last 1 mm of the test period, unless otherwise prescribed in the relevant specification.
During and after the test there shall be no evidence of permanent breakdown, flashover and harmful deformation of the case or seepage of impregnate.