Recovery from a two-vessel low-pressure chiller is running slowly with a single hose on the evaporator. Which connection change usually shortens the job the most?
Correct Answer
D) Connect to the condenser as well, so the flow need not pass through the metering orifice
A centrifugal chiller's condenser and evaporator are joined only through the float valve or fixed orifice that meters liquid between them. That passage is small, and at deep vacuum it throttles the flow badly, so a hose on the evaporator alone has to drag the condenser's contents through a restriction. Putting a second hose on the condenser gives that vessel its own path to the recovery unit and often cuts hours off the vapor phase of the job.
Why This Is the Correct Answer
The metering device between the two vessels is sized for liquid flowing under a pressure difference, not for vapor moving at near vacuum. Connecting to both the evaporator and the condenser removes that restriction from the recovery path, so both vessels empty at once instead of one draining through the other.
Why the Other Options Are Wrong
Option A: Connect a second hose to the same evaporator port, so the flow splits between two smaller lines
Two hoses on one port do not double anything. The restriction is inside the machine, and both lines would still be pulling from the same vessel.
Option B: Connect to the oil cooler as well, so the refrigerant in the oil circuit has a route of its own
The oil cooler is a small circuit and its refrigerant comes out with the rest. Adding it does nothing about the throttling between the two main vessels.
Option C: Connect to the purge discharge as well, so non-condensable gas leaves through a second path
The purge discharge is a narrow line that goes outdoors, and the purge should be shut off during recovery rather than made part of the flow path.
Memory Technique
One hose makes the condenser breathe through a straw. Give it its own hose.
Reference Hint
Recovering from both the evaporator and the condenser avoids pulling the whole charge through the machine's metering orifice or float valve.
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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