A refrigerant vapor detector in a chiller machine room reaches its alarm level. Besides sounding, what is that alarm expected to do?
Correct Answer
D) Start the machine room's emergency ventilation so the space begins clearing itself
A vapor detector is wired to do two things at once: warn the people who might walk in, and start the emergency exhaust that clears the space. Ventilation is what actually reduces the hazard, and it needs to run whether or not anyone is present to press a button. Stopping the machine does not remove vapor that has already escaped, and deliberately discharging the rest of the charge would make the situation far worse.
Why This Is the Correct Answer
The alarm has a warning function and a control function. Sounding the alarm keeps people out of a room that may be oxygen short, and starting the emergency exhaust begins removing the vapor immediately. Both happen automatically because a release can occur when the room is empty and nobody is there to react to it.
Why the Other Options Are Wrong
Option A: Trip the chiller's main disconnect so that the machine stops and cannot restart
Cutting the machine's power stops the compressor but does nothing about refrigerant already in the room, and it may not be desirable in every situation.
Option B: Close the machine room's fire dampers so the vapor cannot reach the rest of the building
Fire dampers serve a different hazard and are actuated by the fire alarm system rather than by a refrigerant detector.
Option C: Open the chiller's relief path so the remaining charge is discharged in a controlled way
Discharging the remaining charge into the relief path would add the rest of the machine's contents to a room that is already contaminated.
Memory Technique
An alarm that only makes noise leaves the vapor where it is. The fans are the half that does the work.
Reference Hint
A machine room refrigerant detector alarms and starts the emergency ventilation for the space.
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?
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?
What should a technician do about the water in the chiller tubes before pulling a deep vacuum on the machine?
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