EPA Section 608 Universal Certification ExamType II (High-Pressure Appliances)Medium
A technician is performing a recovery from a high-pressure appliance containing 15 pounds of R-410A. The recovery unit is operating, but the recovery rate is very slow, and the unit cycling on and off frequently. Which of the following is the MOST likely cause of this issue?
- AThe appliance's filter drier is clogged, impeding refrigerant flow.
- BThe ambient temperature is too low for efficient refrigerant recovery.
- CThe recovery hoses are too short, causing excessive pressure drop.
- DThe recovery unit's condenser is dirty or restricted, leading to high head pressure.
Show answer & explanationAnswer & explanation
Correct answer: D. The recovery unit's condenser is dirty or restricted, leading to high head pressure.
A dirty or restricted condenser in a recovery unit will cause high head pressure, reducing its efficiency and leading to slow recovery rates and frequent cycling as it struggles to condense the refrigerant.
Why the other options are wrong
- A. A clogged filter drier in the appliance would impede refrigerant flow from the appliance to the recovery unit, but the unit itself cycling on and off points more directly to an issue within the recovery unit's operation.
- B. Low ambient temperature generally improves recovery efficiency by helping to condense the refrigerant, not hinder it to cause slow recovery and cycling.
- C. While hose length can affect recovery speed, 'too short' hoses would generally improve flow, not hinder it to this degree.
Recovery Unit Performance Issues
Factors that can negatively impact the efficiency and speed of a refrigerant recovery unit's operation.
- High head pressure often indicates condenser issues.
- Non-condensables reduce efficiency.
- Proper hose sizing and condition are important.
Memory trick: Slow recovery? Check the unit's 'lungs' and 'veins' first!