Nate Electrical Practice Exam

In an automatic pump down system, the compressor is directly controlled by?

1. A thermostat

2. Low pressure control

3. High pressure control

4. Oil pressure control

The correct answer is: Low pressure control

In an automatic pump down system, the compressor is primarily controlled by low pressure control. This form of control is critical because it ensures that the compressor operates within the desired parameters by monitoring and responding to the pressure levels in the system. When the refrigerant pressure drops below a predetermined threshold, the low pressure control mechanism activates the compressor, allowing it to pump down the refrigerant until it achieves the desired low-pressure state. This operation is essential for preventing issues such as flooding and ensuring that the system runs efficiently. The other control types, such as thermostats or high pressure controls, serve different purposes. A thermostat typically regulates temperature by controlling the compressor based on the temperature in the environment or system, while high pressure controls would engage to protect against excessive pressure in the system rather than directly managing routine operation. Oil pressure control focuses specifically on the lubrication and operational integrity of the compressor, rather than its direct operation based on refrigerant pressure levels.