Proper wire/size for heat pump air handler
cross posted in heating and air, but I thought as it pertains to electrical this may be as good a forum:
When installing a heat pump system that has an air handler with emergency type heat strip(s) installed with two breakers in the unit what type of wire should be used to feed power to it? Assume that it replaces either a smaller heat pump system or a traditional electric heat air handler that had a single power feed. Is it better to add a breaker to the main panel and feed the second breaker/disconnect in the air handler or is it better to uprade the wiring and use the appropriate single feed kit for the air handler so both breakers can be fed from one breaker in the main? If going that route what type of wire should be used? In my case there is a 30A breaker and a 60A breaker. My preference would be to protect it at the main panel with a 90 or 100 amp breaker and install a single feed but that would require #3 wire and I am only aware of THHN in that size. Air handler is is about 50 feet from the main panel. Conduit is not totally impossible but would be quite a job. Could I use SE type cable? I am double posting this in electrical.