What has to be done before a technician climbs inside a chiller water box to plug a leaking tube?
Correct Answer
B) Follow confined space entry procedures, including testing the atmosphere and posting an attendant
A chiller water box is a confined space: limited entry and exit, not designed for continuous occupancy, and capable of holding an atmosphere that will not support life. Entry requires the full procedure, which means isolating and locking out energy sources, testing the atmosphere before and during entry, providing ventilation, and posting an attendant outside who stays in contact and never enters to attempt a rescue alone. None of that is optional because the job looks quick.
Why This Is the Correct Answer
Confined space procedure exists because the hazards inside a vessel are invisible and because the most common fatality pattern is a would be rescuer following the first victim in. Atmospheric testing, ventilation, lockout of the water and refrigerant sides, and an attendant outside are the controls that keep both people alive.
Why the Other Options Are Wrong
Option A: Wear a dust mask and leave the machine sitting at a slight vacuum while the work goes on
A dust mask filters particles and does nothing for an oxygen deficient or contaminated atmosphere. Holding the machine in a vacuum while a person is inside it is not a control of any kind.
Option C: Charge the machine shell with nitrogen beforehand so that refrigerant cannot leak into the water box
Nitrogen is an asphyxiant. Putting more of it next to a space someone is about to climb into makes the atmosphere more dangerous, and it does nothing about the entry procedure.
Option D: Leave the purge unit running the whole time so fresh air keeps moving through the shell
A purge unit moves gas off the refrigerant side of the machine, not out of the water box a worker occupies. It is no substitute for atmospheric testing, ventilation, and an attendant.
Memory Technique
Small door, big rules. Test the air, lock the energy, post a watcher.
Reference Hint
Chiller water boxes and shells are confined spaces; entry requires atmospheric testing, lockout, ventilation and an attendant.
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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