EPA EPA System Recovery and Evacuation Procedures 2 — Questions and Answers
Question 1: What is the minimum required evacuation level (in microns) for most commercial refrigeration systems before recharging?
- 5,000 microns
- 500 microns (Correct answer)
- 50 microns
- 29 inches Hg on manifold gauge
Correct answer: 500 microns
Industry best practice and most equipment manufacturer specifications require evacuation to 500 microns or lower before charging a commercial refrigeration system.
Question 2: What type of recovery equipment is required when recovering refrigerant from large appliances (systems over 5 lbs)?
- Any recovery cylinder and hand pump
- EPA-certified recovery equipment meeting ARI-700 standards
- Only manufacturer-approved equipment
- A certified recovery machine with ARI-740 certification (Correct answer)
Correct answer: A certified recovery machine with ARI-740 certification
EPA regulations require that recovery equipment for systems containing more than 5 lbs of refrigerant meet ARI Standard 740 performance requirements.
Question 3: What color are DOT-approved refrigerant recovery cylinders?
- Red with a yellow top
- Gray with a yellow top (Correct answer)
- Blue with a white top
- Green with a black top
Correct answer: Gray with a yellow top
DOT-approved refrigerant recovery cylinders are gray with a yellow top, distinguishing them from new refrigerant cylinders which are color-coded by refrigerant type.
Question 4: What is the maximum fill level (by weight) allowed for recovery cylinders?
- 100% of the cylinder's rated capacity
- 90% of the cylinder's rated capacity
- 80% of the cylinder's rated capacity (Correct answer)
- 60% of the cylinder's rated capacity
Correct answer: 80% of the cylinder's rated capacity
Recovery cylinders must never be filled beyond 80% of their rated capacity by weight to allow for thermal expansion of liquid refrigerant.
Question 5: Which condition requires a technician to use a recovery machine rather than pushing refrigerant to the high side for recovery?
- When the compressor is operational
- When the system has a failed compressor (Correct answer)
- When the system uses HFC refrigerants
- When outdoor temperature is below 40°F
Correct answer: When the system has a failed compressor
When a system compressor has failed, an external recovery machine is required because the system cannot use its own compressor to transfer refrigerant.
Question 6: What is the purpose of installing a filter-drier on the inlet of a recovery machine?
- To increase the recovery rate
- To protect the recovery machine from moisture and contaminants in the system (Correct answer)
- To separate oil from the recovered refrigerant
- To measure the quantity of refrigerant recovered
Correct answer: To protect the recovery machine from moisture and contaminants in the system
An inlet filter-drier protects the recovery machine's compressor and valves from moisture, acid, and particulates that may be present in contaminated systems.
EPA EPA System Recovery and Evacuation Procedures 2
What is the minimum required evacuation level (in microns) for most commercial refrigeration systems before recharging?