Do UL approved gaskets certified per UL 157 still need to be subjected to gasket tests per Annex Y.4.3 and Y.4.4 of UL 62368-1, Ed.3?
More specifically you asked: Annex Y.4 lists specific tests for gasket materials, in particular Y.4.3 and Y.4.4 for gaskets employed in an outdoor enclosure subjected to water or dust. Are these tests required for UL listed gaskets? UL157 contains similar, but not identical requirements - e.g., min. tensile strength requirement in UL157 is 60%, not 75%, but the oven ageing is more severe.
In response, it is noted that a National Difference for USA and Canada, Y.4DV DC of UL62368-1 3rd edition, allows use, as an alternative, gasket materials tested in accordance with UL 157, or the gasket tests in CSA C22.2 No. 94.2 / UL 50E. For other countries, these gasket materials may be accepted at the discretion of receiving NCB. As indicated in sub-clause 4.1.7, whenever standard provides choice between different criteria of compliance, it is manufacturer to decide which shall be used.