An operating unit that has a receiver/storage tank requires refrigerant system service. What should be done when servicing the unit?

When servicing an operating unit with a receiver/storage tank, the appropriate action is to pump down the refrigerant and isolate it in the receiver. This process involves removing the refrigerant from the evaporator and other parts of the system and storing it safely in the receiver/storage tank.

Isolating the refrigerant in the receiver is crucial for several reasons. First, it ensures that the refrigerant is contained and minimizes the risk of leaks during service. Second, it allows technicians to work on the system without the concern of refrigerant escaping or being exposed to atmospheric conditions, which could affect both the environment and the effectiveness of the refrigerant. Lastly, this practice aligns with safe handling procedures and compliance with environmental regulations, as it prevents unnecessary release of refrigerants which can be harmful to the ozone layer and contribute to global warming.

Other options, such as pumping the refrigerant down to the condenser, do not isolate it and may put the system at risk if repairs need to be made, as it still leaves refrigerant in parts of the system that may be exposed during service. Filling the receiver with nitrogen is typically a practice for pressure testing or to help prevent contamination, not a standard step during general service. Decommissioning the unit is an extreme measure