Nate Electrical Practice Exam

What device protects the compressor in air conditioning systems against low oil pressure?

1. Thermostatic overloads

2. High-pressure control

3. Oil failure control

4. Low pressure control

The correct answer is: Oil failure control

The device that protects the compressor in air conditioning systems against low oil pressure is known as the oil failure control. This device monitors the oil level and pressure within the system and can shut down the compressor if it detects that the oil pressure has dropped below a safe level. Low oil pressure can lead to inadequate lubrication of the compressor components, resulting in significant damage or failure. Therefore, having an oil failure control is essential to ensure the reliability and longevity of the compressor by preventing operation under harmful conditions. Thermostatic overloads, on the other hand, protect against overheating rather than directly monitoring oil pressure. High-pressure control devices are designed to respond to excessive pressure in the system, while low pressure control devices are typically concerned with the refrigerant pressure in the system. These devices do not specifically address low oil pressure, making the oil failure control the correct choice for this particular protective function.