What might cause the compressor and condenser fan to not run while the blower motor is operating in an A/C system?

The scenario where the compressor and condenser fan are not running while the blower motor is functioning typically indicates an issue that prevents the compressor from engaging. In this case, the correct choice highlights that if safety devices such as the high-pressure (HP) switch, low-pressure (LP) switch, overload protection, or oil pressure switch are open, they disrupt the circuit needed for the compressor and condenser fan to operate.

These safety devices are crucial for protecting the compressor and the system from damage due to unsafe operating conditions. If any of these switches detect conditions such as excessive refrigerant pressure, low refrigerant levels, or inadequate oil pressure, they will open the circuit to the compressor, causing it to shut down along with the condenser fan, even though the blower motor continues to run to circulate air within the building.

The other options, although related to HVAC system functionality, do not specifically address the scenario as thoroughly. For example, while a faulty capacitor can cause the compressor and condenser fan to fail to start, it typically affects the operation of individual components rather than indicating a failure in crucial protective circuitry. Similarly, a damaged thermostat could disrupt temperature control, but it wouldn't directly cause the compressor to be non-operational without impacting other components as well. A lack of