Ac international comfort model ca5524vkd3

The Outside breaker for unit, or inside breaker may need to be reset.
Does inside fan work? if so transformer is good, and may need a contactor if 24 volts is present and contactor won't energize.

You have to test and see if the contactor is getting 24 volts. If so, then test the coil to see if it is open. If open, then replace. It's really very simple. DrTom4444