HVAC - EPA Certification Practice Exam 2026 – Comprehensive All-in-One Guide to Exam Success!

When a reciprocating compressor has an open discharge service valve, energizing the compressor is never permissible. The reason for this is rooted in the operational principles of refrigeration and air conditioning systems. An open discharge service valve allows refrigerant to exit the compressor directly without following the normal pathway through the system, meaning that the compressor is not pressurized properly and could potentially lead to damaging consequences.

If the compressor is energized with the discharge valve open, it can result in a significant loss of refrigerant, potential overheating, and a lack of lubrication, as the compressor is designed to operate under specific pressure conditions. Running the unit in this state can cause severe mechanical failure, including but not limited to a possible breakdown of internal components.

Always ensure that the discharge service valve is closed and that the system is properly set up before energizing the compressor. This safety measure is critical in preventing damage and maintaining the integrity of the HVAC system.