EPA 608 609 - EPA Refrigerant Handling Certification EPA 608 Type II Practice Test 1 — Questions and Answers
Question 1: Under current EPA Section 608 regulations, Type II commercial refrigeration equipment containing more than 50 pounds of refrigerant must be repaired when the annual leak rate exceeds what percentage?
- 10%
- 20% (Correct answer)
- 35%
- 50%
Correct answer: 20%
The EPA refrigerant management rules set the leak rate repair trigger at 20% per year for commercial refrigeration equipment containing more than 50 lbs of refrigerant. Exceeding this threshold creates a mandatory obligation to locate and repair the leak. Comfort cooling equipment has a lower threshold of 10%, while industrial process refrigeration is allowed 30%.
Question 2: When using EPA-certified recovery equipment manufactured after November 15, 1993, what is the minimum recovery level required (in inches of mercury vacuum) for a Type II system with a refrigerant charge of 200 pounds or more?
- 0 in Hg (atmospheric pressure)
- 4 in Hg
- 10 in Hg (Correct answer)
- 25 in Hg
Correct answer: 10 in Hg
EPA 608 regulations require recovery to at least 10 inches of mercury vacuum for Type II systems with 200 lbs or more of refrigerant when using recovery equipment manufactured after November 15, 1993. Systems with less than 200 lbs require only 10 in Hg as well, but the standard is applied differently based on equipment age and charge size.
Question 3: A technician measures the liquid line temperature on a Type II R-22 system at 95°F. The high-side gauge reads 278 psig, which corresponds to a saturation temperature of 110°F. What is the subcooling value?
- 15°F (Correct answer)
- 5°F
- 25°F
- 205°F
Correct answer: 15°F
Subcooling is calculated by subtracting the actual liquid line temperature from the saturation temperature at the condensing pressure: 110°F − 95°F = 15°F. This value falls within the normal range of 10–20°F and indicates the liquid refrigerant has been cooled below its condensing saturation point, helping prevent flash gas at the metering device.
Question 4: A Type II rooftop air conditioning unit is operating with low suction pressure, abnormally high superheat (above 30°F), low discharge pressure, and reduced cooling capacity. What is the most likely cause?
- Overcharge of refrigerant
- Insufficient refrigerant charge (undercharge) (Correct answer)
- Dirty condenser coil restricting airflow
- Metering device stuck in the open position
Correct answer: Insufficient refrigerant charge (undercharge)
Low suction pressure combined with high superheat and low discharge pressure is the classic symptom pattern of an undercharged system. The refrigerant boils off too early in the evaporator, leaving excessive superheat. An overcharge would cause high suction pressure and low superheat; a dirty condenser would raise discharge pressure; a stuck-open metering device would flood the evaporator and lower superheat.
Question 5: When charging a Type II system with the zeotropic blend R-410A from a cylinder, why must the refrigerant be charged in the liquid phase rather than as a vapor?
- Liquid refrigerant is warmer and reduces the risk of freeze-up during charging
- Vapor charging causes fractionation, altering the blend's composition as it enters the system (Correct answer)
- Liquid charging is faster and reduces the risk of overcharging the system
- Vapor from R-410A cylinders is at too low a pressure to enter the system
Correct answer: Vapor charging causes fractionation, altering the blend's composition as it enters the system
R-410A is a zeotropic blend of R-32 and R-125, which have different boiling points. If charged as vapor, the more volatile component vaporizes preferentially, causing fractionation — the refrigerant entering the system no longer matches the specified blend ratio. Charging as a liquid ensures the exact mixture proportion enters the system as formulated.
Question 6: What is the primary function of a liquid line filter drier in a Type II refrigeration system?
- To add superheat to the refrigerant vapor before it reaches the compressor
- To remove moisture and contaminants from the refrigerant before the metering device (Correct answer)
- To increase subcooling by cooling the liquid line refrigerant
- To regulate refrigerant flow rate through the high side of the system
Correct answer: To remove moisture and contaminants from the refrigerant before the metering device
The liquid line filter drier serves as the system's protection against moisture and contaminants. Moisture in a refrigerant circuit reacts with refrigerant and oil to form acids that corrode internal components. It can also freeze at the metering device, creating an ice restriction that mimics a refrigerant shortage. The drier's desiccant absorbs moisture before it can cause damage.
EPA 608 609 - EPA Refrigerant Handling Certification EPA 608 Type II Practice Test 1
Under current EPA Section 608 regulations, Type II commercial refrigeration equipment containing more than 50 pounds of refrigerant must be repaired when the annual leak rate exceeds what percentage?