Residential HVAC Installation Practice Exam

What controls power to the control transformer in a system?

1. Condensing unit

2. Evaporator coil

3. Conditioned area thermostat

4. Circuit breaker

The correct answer is: Conditioned area thermostat

The other options, such as the condensing unit, evaporator coil, and circuit breaker, are all components or devices within a system that may use power or play a role in controlling the system. However, the conditioned area thermostat is the specific component that controls power to the control transformer. The thermostat senses the temperature in the conditioned area and signals the control transformer to turn on or off, which then powers the rest of the system. This demonstrates the importance of properly maintaining and calibrating the thermostat in order to ensure efficient and effective functioning of the entire system.