EPA 608 Practice Questions

1. The Montreal Protocol
2. The Kyoto Protocol
3. The Clean Air Act
4. The Paris Agreement

Answer: A. The Montreal Protocol (1987) is the treaty that schedules the phaseout of ozone-depleting substances; the Clean Air Act is the U.S. law that carries it out, and Section 608 of that Act is where the EPA refrigerant rules come from. Kyoto and Paris deal with greenhouse gases, not ozone.

Topic: Core: regulations

1. Recovered only
2. Reclaimed
3. Purged
4. Recycled

Answer: D. Recycling means cleaning refrigerant with oil separation and filter-driers so it can go back into the same owner's equipment. Reclaiming means reprocessing it to the AHRI Standard 700 purity specification with a chemical analysis, which only an EPA-certified reclaimer can do; recovery alone is just removing it to a container.

Topic: Core: regulations

1. Nothing, recovered refrigerant may be reused anywhere
2. It must be recycled on site with a filter-drier
3. It must be reclaimed to AHRI 700 by a certified reclaimer
4. It must be relabeled as used refrigerant

Answer: C. Recovered or recycled refrigerant may only go back into equipment belonging to the same owner. When the refrigerant changes ownership it must first be reclaimed to the AHRI Standard 700 specification by an EPA-certified reclaimer, because on-site recycling does not verify purity.

Topic: Core: regulations

1. CFCs, such as R-12
2. HFCs, such as R-134a
3. HCFCs, such as R-22
4. Halons, such as Halon 1301

Answer: B. It is the chlorine atom that breaks apart ozone molecules in the stratosphere. HFCs contain only hydrogen, fluorine and carbon, so their ODP is zero, although they are still potent greenhouse gases and may not be vented. CFCs and HCFCs both contain chlorine, and halons contain bromine, which is even harder on ozone.

Topic: Core: refrigerants & safety

1. When the cylinder feels cold to the touch
2. 60% of its rated capacity
3. 80% of its rated capacity
4. 90% of its rated capacity

Answer: C. Recovery cylinders are never filled beyond 80% of their capacity, so the liquid has room to expand if the cylinder warms; an overfilled cylinder can rupture. Weighing is the only reliable way to know the fill level, since temperature and pressure readings do not tell you how much liquid is inside.

Topic: Core: refrigerants & safety

1. Agree, if it is filled to no more than 80%
2. Agree, if the cylinder is evacuated first
3. Refuse: recovered refrigerant must go straight to a reclaimer
4. Refuse: disposable cylinders may never be refilled

Answer: D. Disposable (DOT 39) cylinders are built for a single fill of virgin refrigerant; refilling them is prohibited by DOT regulations and dangerous, because they are not designed or tested for repeated pressurization. Recovered refrigerant goes into a DOT-approved refillable recovery cylinder, gray with a yellow top, filled to no more than 80%.

Topic: Core: refrigerants & safety

1. A window air conditioner factory-charged with 3 pounds of R-410A
2. A 4-ton split system holding 8 pounds of R-410A
3. A walk-in cooler field-charged with 4 pounds of R-404A
4. A car air conditioner charged with 2 pounds of R-134a

Answer: A. A small appliance is manufactured, charged and hermetically sealed at the factory with 5 pounds or less of refrigerant: refrigerators, freezers, window and room air conditioners, dehumidifiers, vending machines and water coolers. The walk-in cooler is field-assembled, the split system holds more than 5 pounds, and motor vehicle air conditioning falls under Section 609, not 608.

Topic: Type I: small appliances

1. 80% of the charge, or 4 inches Hg vacuum
2. 10 inches Hg vacuum
3. 0 psig on the compound gauge
4. 90% of the charge, or 4 inches Hg vacuum

Answer: D. For small appliances the rule is 90% of the charge when the compressor operates, 80% when it does not, or evacuation to 4 inches of mercury vacuum. If the compressor were seized, 80% would be the target, and heating and gently tapping the compressor helps release refrigerant trapped in the oil.

Topic: Type I: small appliances

1. System-dependent (passive) equipment
2. Self-contained (active) equipment
3. Push-pull equipment
4. Vapor-compression equipment

Answer: A. System-dependent, or passive, recovery equipment captures refrigerant using the appliance's own compressor or internal pressure, often into a non-pressurized container, and may only be used on appliances holding 15 pounds or less. Self-contained equipment has its own pump or compressor and can recover from any size of system.

Topic: Type I: small appliances

1. 10%
2. 15%
3. 20%
4. 30%

Answer: C. The 2016 amendments set the thresholds at 20% for commercial refrigeration, 30% for industrial process refrigeration and 10% for comfort cooling and all other appliances, replacing the older 35% and 15% figures. A leak over the threshold must normally be repaired within 30 days and the repair verified.

Topic: Type II: high-pressure

1. 5%, below the threshold
2. 12.5%, above the 10% comfort-cooling threshold
3. 12.5%, below the 15% comfort-cooling threshold
4. 25%, above the 20% threshold

Answer: B. 25 lb ÷ 200 lb = 12.5% over 12 months, which exceeds the 10% threshold for comfort cooling under the 2016 rule, so the leak must be repaired within 30 days and the repair proven with verification tests. 15% was the comfort-cooling threshold under the older rule, and 20% applies to commercial refrigeration.

Topic: Type II: high-pressure

1. Replacing a liquid-line filter-drier
2. Replacing a thermostatic expansion valve
3. Replacing a Schrader valve core
4. Replacing the condenser coil

Answer: D. A major repair is one that involves removing the compressor, condenser, evaporator or an auxiliary heat-exchanger coil, and before it the system must be pulled down to the vacuum level in the EPA table for its refrigerant and size. For a non-major repair such as a filter-drier or valve change, evacuating to 0 psig before opening is sufficient.

Topic: Type II: high-pressure

1. To remove air and moisture that leak into the vacuum side
2. To separate oil carried over into the condenser
3. To keep the rupture disc from opening at start-up
4. To reduce the charge during a pump-down

Answer: A. Low-pressure refrigerants such as R-123 boil above 50°F at atmospheric pressure, so the evaporator runs below atmospheric pressure and a leak lets air and moisture in rather than refrigerant out. The purge unit collects these non-condensables from the top of the condenser, and a purge that runs more often than usual is a sign of a leak.

Topic: Type III: low-pressure

1. 5 psig
2. 10 psig
3. 15 psig
4. 25 psig

Answer: B. Low-pressure chillers must never be pressurized above 10 psig for leak testing, because the rupture disc that protects the vessel is set to open at 15 psig. Controlled hot water or heating blankets raise the pressure gently; dry nitrogen may also be used, but the same 10 psig limit applies.

Topic: Type III: low-pressure

1. To raise the head pressure and speed recovery
2. To return oil to the compressor sump
3. To keep the water in the tubes from freezing
4. To keep the purge unit from cycling

Answer: C. As the remaining refrigerant evaporates it absorbs heat from the water in the chiller tubes, and without flow that water can freeze and split the tubes. Liquid is recovered first, then vapor with the recovery unit's compressor, down to 25 mm Hg absolute with recovery equipment made after November 15, 1993.

Topic: Type III: low-pressure