🔍 Key Concepts

• Trace the piping labeled (5) between the vacuum pump, carbon filter tank, and evaporator in the RA-0055 schematic. • Note how the carbon filter tank and its air vent are used to separate refrigerant from air/non‑condensables before venting. • Think about the normal role of a system-evacuation vacuum pump versus a purge/recovery vacuum pump on a low-pressure centrifugal chiller.

💭 Think About

• From where does the vacuum pump actually take suction, and to where does it discharge, according to the arrows/labels on the diagram? • When the air vent solenoid opens at 15 psig, what is supposed to be vented to atmosphere, and what is supposed to be recovered and kept in the system? • Which choice best matches a function that would run cyclically during normal operation, as hinted by the note about the vacuum pump cycling for ten minutes?

✅ Before You Answer

• Verify which line (liquid or vapor) leaves the vacuum pump discharge and where it ties back into the system (evaporator or purge chamber). • Confirm that the carbon filter tank’s purpose is to absorb refrigerant and allow mainly air/non‑condensables to be vented at the air vent. • Eliminate any option that describes a one‑time dehydration evacuation or that would intentionally vent refrigerant, instead of recovering it, during normal chiller operation.