edit time was up
UL / NEMA are NA std's. an ISO would be better.
my HVAC unit had a failure, a possible fire hazard, UL said they did not certifiy the unit, Canadian CSA did. i submitted to CSA the issue and got nothing back. this issue could be affecting thousands of York made HVAC units.
basically, improper sizing of a relay. one relay pin basically vaporized off during the inrush amps at turn-on. i have since modified the ckt board, it now uses two hefty solid state relays to control the motor. the small relay is rated 10A, inrush amps at turn-on is around 30A !! the large relay was about max'd out, both were swapped to mosfet SSR's protected from flyback by big MOV's. even some of the wiring was bad, had to replace wiring inside the unit as well as the inadequate 14awg cap cord that was feeding the unit, its now hard wired using 12awg into a fused blade disco.