During recovery from a centrifugal chiller the technician needs to know when the liquid phase has finished and the slow vapor phase is starting. What tells him that?
Correct Answer
A) The evaporator level sight glass runs clear and the flow into the cylinder drops off
Liquid moves fast because the recovery unit is transferring a dense fluid. When the level sight glass on the evaporator clears and the weight going into the cylinder slows sharply, the liquid is gone and everything left is vapor. That is the point at which the hose moves to a high connection and the long part of the job begins. Mistaking a full cylinder or a quiet purge for the end of the liquid phase leads technicians to stop far too early.
Why This Is the Correct Answer
The sight glass shows the liquid refrigerant level in the evaporator directly, and the scale shows how fast mass is leaving the machine. When the glass clears and the transfer rate falls off, the machine holds vapor only. Recognizing the transition matters because the hookup and the expected pace of the job both change at that moment.
Why the Other Options Are Wrong
Option B: The recovery cylinder reaches its eighty percent line and the scale reading stops rising
A cylinder reaching its fill limit says the container is full, not that the machine is empty. The job continues with a fresh cylinder.
Option C: The purge unit shuts off for the first time and its exhaust stops discharging gas
The purge should be shut off during recovery, and its behavior tracks non-condensable gas rather than the liquid level in the evaporator.
Option D: The condenser pressure gauge climbs to zero and the shell reaches atmospheric pressure
Atmospheric pressure would mean the machine is nowhere near the required level, and a low-pressure machine can sit near atmospheric with liquid still in it.
Memory Technique
Watch the glass, not the clock. Clear glass means the easy half is over.
Reference Hint
Liquid is recovered first from a low connection; the evaporator level sight glass shows when the liquid phase is finished.
More epa-608-type-3 Questions
Some jobs on a chiller count as a major repair under the refrigerant rules, which changes what a technician is allowed to do with a badly leaking machine. Which job falls into that category?
An owner asks how many pounds of refrigerant the rules allow to be left inside a chiller once the recovery has been signed off. What is the correct answer to give him?
The motor of a hermetic centrifugal chiller sits inside the pressure boundary rather than outside it on a shaft. What follows from that construction?
An oxygen monitor is used to decide whether a chiller machine room is safe to enter after a refrigerant release. Below what oxygen reading is the atmosphere treated as oxygen deficient?
A low-pressure chiller's rupture disc has a discharge line running from it. Where does that line have to terminate?
A refrigerant vapor detector in a chiller machine room reaches its alarm level. Besides sounding, what is that alarm expected to do?
Which piece of equipment requires a technician to hold Type III certification before it may be serviced?
What property of the refrigerant is what actually places an appliance into the low-pressure category?
During normal operation, what condition exists inside the evaporator of a running low-pressure centrifugal chiller?
In what unit is the required final recovery vacuum for a low-pressure appliance normally expressed?
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