Thermostat normally open and normally closed two

Closed: When set temperature, thermostat normally closed state, when the actual ambient temperature below or close to the set temperature, it will start a load of heating, usually the thermostat normally closed state when the actual temperature is greater than the set temperature, the loads are stopped running.

Open: when the set temperature, the thermostat is in the open State, when the actual temperature is greater than when they approach the set temperature, it will start a load cooling, thermostats are usually in a State of open, when the actual temperature is below the set temperature, the load is always in a State of suspended.