What are the perils the insurance policy protects against called?
A "peril" in insurance speak is "anything that causes a loss" a named peril policy is what types of accidents or "perils" you are covered for. In a basic unendorsed Homeowners policy the person is covered for: Riot or Civil Disorder, Aircraft, Lightning, Fire, Hail, Windstorm, Explosion, Smoke, Theft(Limits on certain items apply), Vehicles, Vandalism, and Volcanic eruption.
Yes, Your air conditioner for your home is covered for the same perils as the rest of your home structure for covered perils such as Fire, Wind, Hail etc. It is not however covered for normal wear and tear or expected maintenance. See your home insurance policy or talk with your insurance agent about the covered perils you selected for your homeowners insurance policy.