EPA Section 608 Technician Certification Study Guide Latest Exam 2023//, Exams of Nursing

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EPA Section 608 Technician Certification

Study Guide Latest Exam 2023//

What are the typical uses of the center port of gauge set? - Correct answer Used during evacuation, charging and recovery procedures. What color are the gauges on a manifold gauge set? - Correct answer Low pressure is blue, High pressure is red. What are the typical ranges of pressure measurements used on the gauges of a manifold gauge set? - Correct answer High side is 0 to 500 PSIG; Low side is 0 to 350 PSIG and 0 to 30 in. Hg below atmospheric pressure. Is the refrigerant leaving a condenser at a high or low pressure? Is it a liquid or a gas? - Correct answer High pressure, liquid. Is the refrigerant entering the expansion valve (variable metering device) a liquid or gas? - Correct answer Liquid, high pressure. Is the pressure of the refrigerant entering the compressor high or low? - Correct answer Low pressure vapor. Where in a refrigerant circuit does a liquid boil to absorb heat? - Correct answer In the evaporator. The refrigerant in the suction line is a gas that has been heated above its saturation. What is this condition called? - Correct answer Superheated vapor. What can cause liquid refrigerant to migrate to a compressor crankcase? - Correct answer If the compressor is located in the coldest location in the circuit.

List two conditions that can quickly damage a compressor that is starting to run? - Correct answer Operating while in a deep vacuum or when the service valves are closed. What system failures require taking an oil sample? - Correct answer A compressor burnout or if the unit has had a leak. Is flushing with refrigerant an acceptable tube cleaning method? - Correct answer No. In addition to preventing and repairing leaks what else should a technician do to conserve refrigerant? - Correct answer Recover and recycle used refrigerants. What factors affect the speed of an evacuation? - Correct answer Pump size, hose length, hose diameter, size of system to be evacuated, ambient temperature, suction line size, and the amount of moisture in the system. How should gauge set hoses be sized for use in evacuating a system? - Correct answer Use the shortest length and the largest diameter possible for the quickest evacuation. At least as large as the vacuum pump inlet. When evacuating what is the benefit of using short hoses with large diameters? - Correct answer Reduces emissions, pressure drop and evacuation time. Which connection determines the preferred size of hoses used with a vacuum pump? - Correct answer The vacuum pump inlet. As the capacity and suction hose size increase what happens to the time needed for an evacuation? - Correct answer Time is reduced. What purpose is served by heating a system during dehydration? - Correct answer To speed up moisture removal.

Does a thorough evacuation remove moisture from a system? - Correct answer Yes. What can happen to oil in the compressor if the moisture is left in an operating system?

• Correct answer The oil will form hydrofluoric and hydrochloric acids which will corrode the internal parts of the system. What is the result of over-evacuating a system? - Correct answer No damage will be done. How can a system be leak checked using a low pressure gauge? - Correct answer Vacuum reading will rise when vacuum pump is turned off. How close should the vacuum gauge be connected to the vacuum pump during evacuation? - Correct answer As far away as possible. When measuring the vacuum of a system being evacuated the system must be isolated. What must be done to the vacuum pump? - Correct answer Turn it off and valve it off. What is ozone? - Correct answer 3 atoms of oxygen. It blocks much of the harmful ultraviolet radiation (uv-b) emitted from the sun and it keeps our earth's temperature stable. How much ozone can a chlorine atom destroy in the stratosphere? - Correct answer One atom can destroy 100,000 ozone molecules. What is Ozone Depletion Potential (ODP)? - Correct answer The ability of any chemical to deplete the ozone layer. What is CFC? - Correct answer Chlorofluorocarbon.

Which refrigerants are CFC's? - Correct answer R-11,12,113,114. Which chemical in the CFC refrigerants does the most damage to the ozone layer? - Correct answer Chlorine. What is an HCFC? - Correct answer Hydrochlorofluorocarbons. Which refrigerants are HCFC's? - Correct answer R-22,123. Which is more harmful to the ozone layer a CFC or an HCFC? - Correct answer CFC's. What is it about CFC's that make them more harmful to the stratosphere? - Correct answer Chemical strength, they will not breakdown in the lower atmosphere. What is an HFC? - Correct answer A fluorocarbon that contains no chlorine. Which refrigerants are HFC's? - Correct answer R-134a,404a,407c,410a. What is the ODP of the HFC refrigerant? - Correct answer Zero. Which refrigerants contain chlorine? - Correct answer CFC's and HCFC's. Which refrigerants have high ODP? - Correct answer CFC's. Which refrigerants have low ODP? - Correct answer HCFC's, HFC's are zero. What is an azeotrope refrigerant? - Correct answer A mixture of two or more compounds where the mixture behaves like a single chemical. Is one of the components of R-500 a CFC? - Correct answer Yes

Does stratospheric ozone help or hurt the work of the earth's protective shield? - Correct answer It helps. What chemical in the stratosphere tells us ozone depletion is occurring? - Correct answer Chlorine-monoxide. How do we know the chlorine in the stratosphere is coming from CFC's? - Correct answer The increase in chlorine and fluorine present in the stratosphere, matches the increase in emissions of CFC's. How do we know CFC's get to the stratosphere? - Correct answer From high altitude air sampling measurements. What role does the ozone layer play in protecting the earth? - Correct answer It blocks much of the harmful ultraviolet radiation (uv-b). What are the effects on health from increased ultraviolet radiation? - Correct answer Skin cancer, cataracts, human immunity is reduced. What are the effects on the environment? - Correct answer Timber growth is reduced, crop yields lowered, marine life and the food chain are impaired. Is ozone depletion a problem for the United States only or a global problem? - Correct answer A global problem. What is the Montreal Protocol? - Correct answer A treaty that called for the reduction of production of CFC's. The Montreal Protocol calls for the regulation of what chemicals? - Correct answer Ozone depleting compounds, CFC's, HCFC's, and Halons.

On what date was the production and importation of all CFC's phased out? - Correct answer In the U.S., after December 31, 1995. Where will we get replacements? - Correct answer Through recovery of existing refrigerants. What steps are called for by the Clean Air Act? - Correct answer Taxes on production and use, standards set for the recovery of refrigerants. What is prohibited by the Clean Air Act? - Correct answer Venting. Do state and local laws have priority over federal law? Can they be less strict? - Correct answer No. Cities or states can create their own laws but they must be at least as strict as federal laws. To prevent damage to the ozone layer the U.S. is making laws to capture the CFC's now in use. What else does the new law do to restrict the release of CFC's? - Correct answer Allows states and municipalities to create their own laws to prevent and monitor the release of CFC and HCFC materials into the atmosphere. By recovering refrigerants we ensure adequate supplies and prevent venting. What else does the recovery of refrigerants accomplish? - Correct answer Prevents stratospheric ozone depletion. The Clean Air Act phases out CFC/HCFC production and prohibits venting. What else does it require? - Correct answer Standards to be set for recovery of all refrigerants prior to appliance service and disposal. Falsifying or failing to keep required records failing to reach required evacuation levels and knowingly releasing CFC or HCFC refrigerants, are a violations of the Clean Air

Act. What activity with a substitute refrigerant is also a violation? - Correct answer Knowingly venting CFC's, HCFC's and their substitutes. Which refrigerants must be recovered prior to opening a system? - Correct answer All refrigerants as of 11-15-1995. What releases of a CFC and HCFC are violations of the Clean Air Act? - Correct answer Any knowingly vented refrigerants. On what date did it become illegal to vent CFC and HCFC refrigerants? - Correct answer July 1, 1992. Which appliances are covered by Section 608? - Correct answer Any device which contains and uses a class 1 or class 2 substance as a refrigerant and is used for household or commercial purposes. What is the primary reason the EPA requires a service aperture or process stub on all appliances? - Correct answer For adding or removing refrigerant from the appliance. Who sets the regulations for recovery machines? - Correct answer EPA. What is a "self-contained" recovery machines? - Correct answer A recovery machine that has its own compressor to pump refrigerant out of the system. Is HCFC-123 a "low or "high" pressure refrigerant? - Correct answer Low pressure. Is CFC-12 a "low" or "high" pressure refrigerant? - Correct answer High pressure. What is the smallest container in which refrigerants may be sold to a Section 608 certified technicians. - Correct answer 20 pounds.

What must you do to the refrigerant in an appliance before disposing of the appliance? - Correct answer Recover refrigerant or verify that the refrigerant was previously recovered. Who is responsible for removing the refrigerant from household refrigerators prior to disposal? - Correct answer The final person in the disposal chain. (Scrap metal recyclers, landfill owner, etc) What is the penalty for violation of the Clean Air Act? - Correct answer Fines up to $27,500 per violation per day and possible loss of technician certification. How much is the bounty for information leading to a conviction? - Correct answer Up to $10,000. What can happen if a technician cannot demonstrate an ability to use recovery or recycling equipment? - Correct answer May result in revocation of the technician's certification. What is the name of the process that removes refrigerant from a system and stores it without testing or processing? - Correct answer Recovery. What is the name for the process that removes moisture and acids from refrigerant but does not test the refrigerant? - Correct answer Recycling. What is the name for the process that removes moisture and acids from refrigerant and also chemically tests the refrigerant? - Correct answer Reclaim. What must be done with reclaimed refrigerant before it can be legally resold? - Correct answer Chemically tested to ARI Standard 700, the purity level of factory new refrigerant.

What is the preferred instrument for detecting small leaks? - Correct answer Electronic leak detector and Ultrasonic detector. What is an inert gas typically used in leak detection? - Correct answer Dry nitrogen. What is typically indicated by a dehydrated system failing to hold a vacuum? - Correct answer Leaks. What should be done when recovering the refrigerant form a system where the refrigerant has been improperly mixed? - Correct answer Recover into a separate container. Can mixed refrigerants be reclaimed? - Correct answer No. What precautions should be taken when recovering refrigerant from systems with multiple service valves? - Correct answer Insure that liquid is not trapped between service valves. What is the effect of low ambient temperature on the time required to complete a recovery of refrigerant? - Correct answer Increases recovery time. Technicians must explain to customers that recovery is necessary and it is required by law. What else should the technician tell the customer? - Correct answer That all professional service personnel are duty bound to follow the law and protect the environment. What is different about any leaks in systems charged with a blended refrigerant? - Correct answer Because their vapor pressures can vary widely with temperature they leak from a system at uneven rates.

What is "temperature glide"? - Correct answer A family of lines depicting pressure versus temperature curve. What is ternary blend? - Correct answer A blend of three different refrigerants. How should systems using blended refrigerants be charged? - Correct answer In liquid form into the high side of the system. Is there a "drop-in" refrigerant for CFC-12? - Correct answer No. How do you leak check an HFC-134a system with a partial charge (no HFC-134a detector available)? - Correct answer Recover the remaining 134a and then pressurize the system with nitrogen and a trace charge of R-22 so you can use an HCFC electronic leak detector. What is the preferred oil to be used with HFC-134a? - Correct answer Polyolester or ester based. Can ester based oils be mixed with other oils? - Correct answer No. What does "hygroscopic" mean? - Correct answer Oil that absorbs moisture easily. What lubricant is recommended for use with a ternary blend? - Correct answer Depends on the blend: For HCFC's-Alkylbenze, For HFC's-Ployolester. Safety glasses and butyl-lined gloves should be worn for what procedures? - Correct answer When operating recovery or recycling devices and when handling and refilling refrigerant cylinders. What safety component must be used whenever dry nitrogen is used to pressurize a system? - Correct answer Pressure regulator.

Safety rules for technicians such as: no open flame or hot steam near a refrigerant never cutting or brazing a charged refrigerant line, and never using oxygen to purge or pressurize lines, are all important. Which one should a technician follow? - Correct answer All of them. What is a Material Safety Data Sheet? - Correct answer A sheet the states the safety ratings and precautions to be taken for use and handling of chemicals. What safety classification within the ASHRAE standard is the most safe? - Correct answer A1. What is caused by tie inhaling of refrigerant vapors? - Correct answer Heart irregularities or Asphyxia. What is the major causes of death involving refrigerants? - Correct answer Oxygen deprivation. What breathing problem can be caused by CFC-12? - Correct answer Asphyxia. How can ice be removed from a sight glass? - Correct answer With alcohol spray. What must be done with a badly corroded relief valve? - Correct answer It must be replaced. Where can you find the allowable test pressure on a system? - Correct answer Unit data plate. Can oxygen be used to check for leaks? If not why not? - Correct answer No. Oxygen in the presence of oil under high pressure can be explosive.

What is the likely result of heating a recovery cylinder with an open flame? - Correct answer Refrigerant will decompose into a toxic material, venting of refrigerant in the atmosphere or the tank may explode. What is the primary purpose of a disposable cylinder? - Correct answer For virgin refrigerant from the manufacturer. To what internal pressure should a disposable cylinder be reduced to for disposal? - Correct answer Reduced to at least 0 PSIG. Should you ever use a disposable cylinder for refrigerant recovery? - Correct answer No. To dispose of a cylinder you should be sure all refrigerant is recovered and the cylinder is no longer usable. What else should you do? - Correct answer Puncture the container before disposal. For safety refrigerant cylinders should not be rusted or damaged and always properly color coded. What additional step should also be taken with these cylinders? - Correct answer Properly secured at all times. What is the proper color code for recovery cylinders? - Correct answer Gray with a yellow top. What is the maximum percent by weight that a cylinder may be filled? - Correct answer 80%. What can happen if a cylinder is overfilled? - Correct answer Hydrostatic pressure could cause the cylinder to explode.

List three methods for measuring the fill level of a recovery cylinder. - Correct answer Floats, thermistor type sensors, and weighing scales. How often must reusable cylinders be hydrostatically tested? - Correct answer Every five years. Why must only refillable cylinders be used for transport? - Correct answer Federal code of regulations title 49 (parts 100-177) states this. What must be affixed to a refrigerant cylinder prior to its shipment to a reclaimer? - Correct answer DOT classification tag. What is the purpose of a DOT classification tag? - Correct answer For transportation purposes. What is the correct shipping position for a refrigerant cylinder? - Correct answer In a vertical or upright position with their valves at the top. What is the EPA definition of a small appliance? - Correct answer Appliances typically charged at the factory with five pounds or less of refrigerant. Refrigerators and freezers designed for home use, room air conditioners, including window and PTAC units, package heat pumps, dehumidifiers, under the counter ice makers, vending machines and drinking water coolers. Does the EPA require the repair of leaks on small appliances? - Correct answer Repair of leaks on small appliances is not required, but leaks should be repaired whenever possible. What EPA certification type must technicians have to service any appliance that EPA calls a "small appliance"? - Correct answer Type 1 or Universal.

What service aperture may be used on small appliance? - Correct answer Access tubes or process tubes. What is the name for a fitting used to connect a recovery device to an appliance, which can close to prevent loss of refrigerant form hoses? - Correct answer Low-loss fitting. (shut-off valve) What is the primary purpose for using hand valves or self-sealing hoses when using a gauge set? - Correct answer To prevent loss of refrigerant. Which refrigerants must be recovered under Section 608 of the EPA regulations? - Correct answer CFC, HCFC and HFC refrigerant. Is there a "drop-in" refrigerant for CFC-12? - Correct answer No. What is the replacement refrigerant for CFC-12 in household refrigerators? - Correct answer HFC-134a. What can be determined by taking an accurate temperature and pressure reading of a container holding a recovered refrigerant? - Correct answer Check for non- condensables and the type of refrigerant. When doing a non-condensables check, a recovery cylinder should stabilize in temperature before any readings are taken. Why? - Correct answer To find the correct pressure for that temperature on a T/P chart. What is the internal pressure of CFC-12 refrigerant stored at 75 deg. F? - Correct answer 77 PSIG.

What is the exception to the rule that says that someone servicing and appliance must have at least one self-contained recovery machine available at their place of business?

• Correct answer Only when the person is working on a small appliance. Ammonia hydrogen, and water can be found in the refrigerators in some campers and other recreational vehicles. Should these compounds be recovered with EPA approved recovery equipment? - Correct answer No. May the nitrogen used for purging or pressurizing a system be vented to the atmosphere? - Correct answer Yes. When may a technician recover only 80% of the refrigerant in a small appliance? - Correct answer In a system dependent recovery with a non-operating compressor? May a technician use a passive recovery machine for recovery from a domestic refrigerator? - Correct answer Yes. What requirements are placed on recovery machines built after November 15 1993? - Correct answer Must be able to recover 80% of the refrigerant if the compressor is inoperative or 90% if the compressor is operative. Must be EPA certified. When using a recovery machine manufactured after November 15 1993, what percentage of the refrigerant must be recovered in a household refrigerator with an operating compressor? What percentage if the compressor is NOT operating? - Correct answer 80%, 90%. Is a certified technician responsible for future changes in EPA regulations? - Correct answer Yes. What type of certification is required to purchase CFC and HCFC refrigerants? - Correct answer Type 1.

What must be done with any regulated refrigerant vented from a graduated charging cylinder? - Correct answer It must be recovered. What first step must you always take before starting a recovery of refrigerant form any equipment? - Correct answer Check which refrigerant is being used. What is a "system-dependent" recovery machine? - Correct answer System dependent recovery machines rely on the compressor of the system being serviced, or the pressure of the refrigerant to pump the refrigerant into a recovery drum. Describe a system-dependent (passive) recovery process for small appliances. - Correct answer Evacuate or cool a cylinder. Connect the high and low hoses to the system. Pull refrigerant into the cylinder with vacuum or the low tank pressure. What two conditions require that you access both the high and low side of the system for refrigerant recovery? - Correct answer When there is an inoperative compressor on the system or when necessary to reach required recovery levels. What are the benefits of accessing the low and high side access valves when recovering refrigerant from a system with an inoperative compressor? - Correct answer It speeds up recovery, improves efficiency and may be necessary to reach required recovery levels. How should you access the system and should you run the compressor when using a system-dependent (passive) recovery on a refrigerator with an operable compressor? - Correct answer Access the high side and run the compressor. Which access valve (s) should you connect to when recovering from a system with an operating compressor and a completely restricted capillary tube? - Correct answer High side valve.

When using a self-contained (active) recovery device what two conditions can cause excessive pressure on the recovery machine's high side? - Correct answer A recovery container that is not properly evacuated or one that has unopened valve. Why should defrost heaters be turned on during a recovery from a small appliance? - Correct answer To speed up refrigerant release from the oil. When should entrapped refrigerant from oil be recovered? - Correct answer Any time oil is removed from a large system and on small appliances when using system dependent recovery with a non-operating compressor. What does striking the appliance compressor do during a recovery? - Correct answer Helps to free refrigerant that may be trapped in the oil. A recovery machine should be checked daily for what? - Correct answer Refrigerant leaks. Can a standard vacuum pump be used as a recovery machine? - Correct answer In theory yes, but unlikely. First it would have to be certifiable, second it would have to be connected to a non-pressurized recovery container. Should technicians ever mix refrigerants in the field? - Correct answer No. How should you recover refrigerant that is different from the refrigerant you usually recover? - Correct answer Different refrigerants must be placed in recovery vessels containing the same type of refrigerant. What can a reclaimer do with any mixed refrigerant you ship to them? - Correct answer They may either refuse to process and return it at owner's expense or agree to destroy the refrigerant for a substantial fee.

To ship recovered refrigerant you must label the container and complete all necessary paperwork. What else should you do? - Correct answer Use DOT approved cylinders. What federal agency sets the standards for portable refillable tanks or containers used to ship CFC or HCFC refrigerants? - Correct answer Department of Transportation (DOT). Safety glasses and butyl-lined gloves should be worn fro what procedures? - Correct answer When you are connecting and disconnecting hoses. Piercing valves are used for what purpose? - Correct answer To allow access to the sealed system for recovery. On what materials are piercing valves used? - Correct answer Copper or aluminum refrigerant lines. What should be done to a piercing type Schrader valve after it is installed on a charged system? - Correct answer It should be capped after any service procedure. Why should solder-less type piercing valves be removed after completion of repairs? - Correct answer To prevent leaks. What are the critical maintenance checks done to a Schrader valve? - Correct answer Periodically checked for leaks and replaced if damaged. What does a pungent odor detected after opening a system mean? - Correct answer It might mean acids are present due to a compressor burnout. What do you do if the oil is contaminated? - Correct answer Tubing flushing might be required.

What system pressure would indicate a recovery should not be performed? - Correct answer 0 PSIG. What are the current methods used to monitor the 80% fill level in a recovery tank? - Correct answer Floats, thermistor-type sensors and weighing scales. Why do large refrigerant leaks cause suffocation? - Correct answer Refrigerants will replace air in a confined space leading to possible oxygen starvation. Before entering an area of a large leak of refrigerant what apparatus must be worn? - Correct answer Self contained breathing apparatus. What should be done if a large leak occurs and no breathing apparatus is available? - Correct answer Ventilate the space and leave the area. Which acids are formed when refrigerant touches sources of high heat? - Correct answer Hydrochloric and hydrofluoric acids and phosgene gas. What safety component must be used whenever dry nitrogen is used to pressurize a system? - Correct answer Nitrogen tanks should be equipped with a regulator. What information does DOT require when shipping refrigerant cylinders? - Correct answer Shipping papers must indicate the refrigerant type and number of cylinders. Which government agency sets the standards for refillable refrigerant cylinders used to transport CFC and HCFC refrigerants? - Correct answer Department of Transportation (DOT). What component is always replaced after a a system is opened for service? - Correct answer Filter-driers.

What is the purpose of the moisture indicator in a sight glass? - Correct answer To permit a check of moisture content in the system. What does "back-seating" a suction valve do? - Correct answer Allows flow through the main line while closing the access port. What will non-condensables do to the pressures in a refrigerant circuit? - Correct answer Increase discharge pressure. What causes oil foaming in a system and where does it normally occur? - Correct answer Oil that is mixed with refrigerant will foam in the compressor crankcase. What system failures require taking an oil sample? - Correct answer Compressor burnout or if the unit has had a leak. A vacuum pump that is too large can cause what problem? - Correct answer It can cause moisture to freeze in the system. Where is a receiver typically installed on a system? - Correct answer At the outlet of the condenser. What will be the boiling temperature of HFC-134a be at 0 PSIG? - Correct answer - degrees F. Is it a requirement that recovery machines contain an oil separator? - Correct answer No. Which refrigerant is typically used on a residential split system air conditioner? - Correct answer HCFC-22.

Is the refrigerant leaving a receiver a liquid or a gas? Is it at a high or low pressure? - Correct answer Liquid, high pressure. What is the initial charging method of a system when the charge is specified at 70 pounds? - Correct answer Charged in liquid state. Is the receiver on the high or low side of a system? - Correct answer High side. What is the minimum recommended capability (measured in microns) of a vacuum pump used for evacuations? - Correct answer Should pull a vacuum of 500 microns. What is the pressure of a CFC-12 machine at 72 deg. F while the machine is idle? - Correct answer 73 PSIG. What is the preferred unit of measurement for checking a deep vacuum? - Correct answer Microns. Where is an accumulator located in a refrigeration system? - Correct answer On the suction line before the compressor. To prevent freezing of any moisture in a CFC-12 system vapor should first be charged until the pressure is at what level? - Correct answer 33 PSIG What gas should be used during an evacuation to increase pressure to prevent freezing? - Correct answer Dry nitrogen. What is the purpose of a compressor heater? - Correct answer To reduce the amount of refrigerant in the lubricating oil. How is moisture remaining from an evacuation removed from the refrigerant in a system? - Correct answer By the filter-drier.

What is the preferred method of leak checking a built-up system prior to charging? - Correct answer Bubble solution. What would a technician initially look for during a visual inspection of a leaking hermetic system? - Correct answer Stains around tubing and fittings. What is typically indicated by excessive superheat on a high-pressure system? - Correct answer Undercharged system, possibly the result of a leaky system. Which refrigerant should be used for a trace charge during leak detection? - Correct answer R-22. How do you leak check an HFC-134a system with a partial charge (no HFC-134a detector available)? - Correct answer Recover remaining 134a, pressurize the system with nitrogen and a trace charge of R-22 so you can use an HCFC electronic leak detector. For what purpose are soap bubbles used in leak checking? - Correct answer For a visual check for leaks. Shaft seals on an open type compressor are susceptible to what failures? - Correct answer Refrigerant leaks. What leak rate is permissible on industrial and process refrigeration? - Correct answer Effective 6/14/93, any leak rate of 35% or more on equipment with 50 lbs. of charge or more must be repaired. Less than 35% is permissible. What leak rate is permissible on equipment (other than industrial or process equipment) that contains more than 50 lbs. of refrigerant? - Correct answer Less than 15% annually.

What is the easiest way to check the type of refrigerant used in a packaged rooftop system? - Correct answer By the equipment data plate. Refrigerant will recover fastest in which phase liquid or vapor? - Correct answer Liquid. Which refrigerant line should a recovery machine be attached to in order to recover liquid refrigerant from a system? - Correct answer To the liquid line. After a liquid recovery what must be done with the vapor still in the system? - Correct answer A vapor recovery must be performed. Recovering in a vapor phase reduces unwanted loss of what? - Correct answer Oil and unwanted contaminants from the system to the recovery machine and recovery drum. On a high pressure system recovery should the recovery cylinder be heated or cooled?

• Correct answer Cooled. What must be done to a recovery machine when changing to a different refrigerant? - Correct answer Clean out all residual refrigerant, change oil, replace filters, evacuate machine by pump-out or with another machine. What besides filters must periodically be changed out on a recovery machine? - Correct answer Oil. Recovered refrigerant can contain oil and acids. Name another compound found in refrigerants? - Correct answer Moisture. What is the water source for a condensing coil on a water-cooled recovery machine? - Correct answer Municipal water tap.

What access location should you use when recovering from an air cooled system with its condenser several feet above the evaporator? - Correct answer Suction line. What access location should you use when recovering from a system with its condenser below the evaporator? - Correct answer Liquid line. Before using a recovery unit - Correct answer the technician should check service valve positions and check the recovery unit oil level. What additional step must be taken?,All solenoid valves should be open. What is the primary purpose for using hand valves or self-sealing hoses when using a gauge set? - Correct answer To prevent loss of refrigerant when connecting and disconnecting hoses. What can cause recovery equipment with a hermetic compressor to overheat when drawing a deep vacuum? - Correct answer No airflow over the compressor body or no suction gas flow over the internal motors, or a combination of the two. What is the reason for not operating a hermetic refrigeration compressor while it is in a deep vacuum? - Correct answer To prevent overheating the compressor motor. What is the reason for not starting a reciprocating compressor with its discharge service valve closed? - Correct answer To prevent overheating the compressor motor. When can a "system-dependent" recovery device be used? - Correct answer On small appliances as long as the device meets EPA standards and the technician adheres to the servicing procedures specified for the recovery equipment. Cannot be used on systems with more than 15 lbs. of refrigerant.

What vacuum level must you reach when recovering from a system with 38 pounds of R-502 using a recovery machine manufactured in 1995? - Correct answer 10 inches of Hg. What is EPA's definition of a "major repair"? - Correct answer Any repair that involves the removal of the compressor, evaporator, condenser, or any auxiliary heat exchanger coil. Prior to making a major repair what vacuum level must you pull when using recovery equipment manufactured in 1996 on a unit with 215 lbs. of CFC-12? - Correct answer 15 inches of Hg. What vacuum level must you pull when using recovery equipment manufactured in 1992 when disposing of an appliance containing 12 lbs. of R-500? - Correct answer 4 inches of Hg. Under what circumstances may a technician recover the CFC refrigerant in an appliance to atmospheric pressure only? - Correct answer If leaks are in the system or if recovery to target levels would contaminate the refrigerant. What procedure should be performed on an empty recovery cylinder before it is used for storing recovered refrigerant? - Correct answer It must be evacuated of all non- condensables. What may legally be done with the refrigerant recovered from a system in order to replace a condenser coil? - Correct answer Reused in the original system or transferred to another system with the same owner after it is checked so that it is free of non- condensables. When servicing an operating unit with a receiver where should the recovery hoses be attached to the unit? - Correct answer To the liquid line.