HVAC - EPA Certification Practice Exam

Which of the following components must be isolated in a parallel compressor system to avoid issues?

1. Receiver tank

2. Condenser

3. Open equalization connection

4. Evaporator

The correct answer is: Open equalization connection

In a parallel compressor system, isolating the open equalization connection is crucial for maintaining proper operation and efficiency of the system. The open equalization connection allows for pressure balancing between the compressors. If left unisolated, fluctuations in pressure can lead to imbalances among the compressors, potentially causing one or more of them to run inefficiently, cycle excessively, or experience unnecessary wear and tear. By isolating the open equalization connection, each compressor can operate more independently, which helps to optimize the overall performance of the system. It minimizes the risk of one compressor taking on too much load while another runs too lightly, which can lead to performance issues or even compressor failure. In contrast, the receiver tank, condenser, and evaporator are critical components that are necessary for the broader functionality of the HVAC system. These components handle refrigerant storage, heat exchange, and cooling processes, and generally don't need isolation in the same manner as the equalization connection to avoid operational issues.