What routine record helps an operator spot a developing leak on a low-pressure chiller before the charge is gone?
Correct Answer
D) A log of how long the purge unit runs each day
On a machine whose leaks draw air inward, the purge unit is the only component whose behavior changes directly with leak size. Logging purge run time daily produces a trend line, and a trend line makes a slow leak visible long before the charge level or performance does. The other readings are worth taking for their own reasons, but none of them respond specifically to air entering the machine the way purge run time does.
Why This Is the Correct Answer
Purge run time responds directly and proportionally to the amount of air entering the machine, so a daily log turns a gradual leak into a visible upward trend. That gives the plant time to schedule a repair rather than reacting after the machine has lost a large part of its charge.
Why the Other Options Are Wrong
Option A: A log of chilled water outlet temperature taken every hour
Chilled water temperature reflects load and control setpoint. It moves for a dozen reasons that have nothing to do with a leak.
Option B: A log of oil pressure recorded at each startup
Oil pressure tracks the lubrication system and tells you nothing about non-condensables in the condenser. It moves with oil temperature, pump wear and filter condition, none of which relate to air in the machine.
Option C: A log of compressor amp draw at full load
Amp draw does rise as non-condensables build, but it also moves with load and condenser water temperature, so it is a much noisier indicator.
Memory Technique
Log the purge clock. A rising clock means a growing hole.
Reference Hint
Daily purge run time logs are the standard early warning for air leaks into low-pressure appliances.
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?
People Also Study
Business & Financial Management
120 questions · 70% to pass
Contract Administration
60 questions · 70% to pass
Project Management
60 questions · 70% to pass
Related Study Resources
Previous Question
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?
Next Question
A purge unit on a low-pressure chiller cycles and discharges through a line to the outdoors. What is in that discharge?