Download EPA Section 608 Technician Certification Study Guide | 100% Correct Answers | Verified and more Exams Chemistry in PDF only on Docsity!
EPA Section 608 Technician Certification
Study Guide | 100% Correct Answers |
Verified | Latest 2024 Version
What are the typical uses of the center port of gauge set? - ✔✔Used during evacuation, charging and recovery procedures. What color are the gauges on a manifold gauge set? - ✔✔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? - ✔✔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? - ✔✔High pressure, liquid. Is the refrigerant entering the expansion valve (variable metering device) a liquid or gas? - ✔✔Liquid, high pressure. Is the pressure of the refrigerant entering the compressor high or low? - ✔✔Low pressure vapor. Where in a refrigerant circuit does a liquid boil to absorb heat? - ✔✔In the evaporator. The refrigerant in the suction line is a gas that has been heated above its saturation. What is this condition called? - ✔✔Superheated vapor. What can cause liquid refrigerant to migrate to a compressor crankcase? - ✔✔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? - ✔✔Operating while in a deep vacuum or when the service valves are closed.
What system failures require taking an oil sample? - ✔✔A compressor burnout or if the unit has had a leak. Is flushing with refrigerant an acceptable tube cleaning method? - ✔✔No. In addition to preventing and repairing leaks what else should a technician do to conserve refrigerant? - ✔✔Recover and recycle used refrigerants. What factors affect the speed of an evacuation? - ✔✔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? - ✔✔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? - ✔✔Reduces emissions, pressure drop and evacuation time. Which connection determines the preferred size of hoses used with a vacuum pump? - ✔✔The vacuum pump inlet. As the capacity and suction hose size increase what happens to the time needed for an evacuation? - ✔✔Time is reduced. What purpose is served by heating a system during dehydration? - ✔✔To speed up moisture removal. Does a thorough evacuation remove moisture from a system? - ✔✔Yes. What can happen to oil in the compressor if the moisture is left in an operating system? - ✔✔The oil will form hydrofluoric and hydrochloric acids which will corrode the internal parts of the system.
Which is more harmful to the ozone layer a CFC or an HCFC? - ✔✔CFC's. What is it about CFC's that make them more harmful to the stratosphere? - ✔✔Chemical strength, they will not breakdown in the lower atmosphere. What is an HFC? - ✔✔A fluorocarbon that contains no chlorine. Which refrigerants are HFC's? - ✔✔R-134a,404a,407c,410a. What is the ODP of the HFC refrigerant? - ✔✔Zero. Which refrigerants contain chlorine? - ✔✔CFC's and HCFC's. Which refrigerants have high ODP? - ✔✔CFC's. Which refrigerants have low ODP? - ✔✔HCFC's, HFC's are zero. What is an azeotrope refrigerant? - ✔✔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? - ✔✔Yes Does stratospheric ozone help or hurt the work of the earth's protective shield? - ✔✔It helps. What chemical in the stratosphere tells us ozone depletion is occurring? - ✔✔Chlorine-monoxide. How do we know the chlorine in the stratosphere is coming from CFC's? - ✔✔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? - ✔✔From high altitude air sampling measurements. What role does the ozone layer play in protecting the earth? - ✔✔It blocks much of the harmful ultraviolet radiation (uv-b). What are the effects on health from increased ultraviolet radiation? - ✔✔Skin cancer, cataracts, human immunity is reduced. What are the effects on the environment? - ✔✔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? - ✔✔A global problem. What is the Montreal Protocol? - ✔✔A treaty that called for the reduction of production of CFC's. The Montreal Protocol calls for the regulation of what chemicals? - ✔✔Ozone depleting compounds, CFC's, HCFC's, and Halons. On what date was the production and importation of all CFC's phased out? - ✔✔In the U.S., after December 31, 1995. Where will we get replacements? - ✔✔Through recovery of existing refrigerants. What steps are called for by the Clean Air Act? - ✔✔Taxes on production and use, standards set for the recovery of refrigerants. What is prohibited by the Clean Air Act? - ✔✔Venting. Do state and local laws have priority over federal law? Can they be less strict? - ✔✔No. Cities or states can create their own laws but they must be at least as strict as federal laws.
Is HCFC-123 a "low or "high" pressure refrigerant? - ✔✔Low pressure. Is CFC-12 a "low" or "high" pressure refrigerant? - ✔✔High pressure. What is the smallest container in which refrigerants may be sold to a Section 608 certified technicians. - ✔✔20 pounds. What must you do to the refrigerant in an appliance before disposing of the appliance? - ✔✔Recover refrigerant or verify that the refrigerant was previously recovered. Who is responsible for removing the refrigerant from household refrigerators prior to disposal? - ✔✔The final person in the disposal chain. (Scrap metal recyclers, landfill owner, etc) What is the penalty for violation of the Clean Air Act? - ✔✔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? - ✔✔Up to $10,000. What can happen if a technician cannot demonstrate an ability to use recovery or recycling equipment? - ✔✔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? - ✔✔Recovery. What is the name for the process that removes moisture and acids from refrigerant but does not test the refrigerant? - ✔✔Recycling. What is the name for the process that removes moisture and acids from refrigerant and also chemically tests the refrigerant? - ✔✔Reclaim.
What must be done with reclaimed refrigerant before it can be legally resold? - ✔✔Chemically tested to ARI Standard 700, the purity level of factory new refrigerant. What is the preferred instrument for detecting small leaks? - ✔✔Electronic leak detector and Ultrasonic detector. What is an inert gas typically used in leak detection? - ✔✔Dry nitrogen. What is typically indicated by a dehydrated system failing to hold a vacuum? - ✔✔Leaks. What should be done when recovering the refrigerant form a system where the refrigerant has been improperly mixed? - ✔✔Recover into a separate container. Can mixed refrigerants be reclaimed? - ✔✔No. What precautions should be taken when recovering refrigerant from systems with multiple service valves? - ✔✔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? - ✔✔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? - ✔✔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? - ✔✔Because their vapor pressures can vary widely with temperature they leak from a system at uneven rates. What is "temperature glide"? - ✔✔A family of lines depicting pressure versus temperature curve. What is ternary blend? - ✔✔A blend of three different refrigerants.
What safety classification within the ASHRAE standard is the most safe? - ✔✔A1. What is caused by tie inhaling of refrigerant vapors? - ✔✔Heart irregularities or Asphyxia. What is the major causes of death involving refrigerants? - ✔✔Oxygen deprivation. What breathing problem can be caused by CFC-12? - ✔✔Asphyxia. How can ice be removed from a sight glass? - ✔✔With alcohol spray. What must be done with a badly corroded relief valve? - ✔✔It must be replaced. Where can you find the allowable test pressure on a system? - ✔✔Unit data plate. Can oxygen be used to check for leaks? If not why not? - ✔✔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? - ✔✔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? - ✔✔For virgin refrigerant from the manufacturer. To what internal pressure should a disposable cylinder be reduced to for disposal? - ✔✔Reduced to at least 0 PSIG. Should you ever use a disposable cylinder for refrigerant recovery? - ✔✔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? - ✔✔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? - ✔✔Properly secured at all times. What is the proper color code for recovery cylinders? - ✔✔Gray with a yellow top. What is the maximum percent by weight that a cylinder may be filled? - ✔✔80%. What can happen if a cylinder is overfilled? - ✔✔Hydrostatic pressure could cause the cylinder to explode. List three methods for measuring the fill level of a recovery cylinder. - ✔✔Floats, thermistor type sensors, and weighing scales. How often must reusable cylinders be hydrostatically tested? - ✔✔Every five years. Why must only refillable cylinders be used for transport? - ✔✔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? - ✔✔DOT classification tag. What is the purpose of a DOT classification tag? - ✔✔For transportation purposes. What is the correct shipping position for a refrigerant cylinder? - ✔✔In a vertical or upright position with their valves at the top. What is the EPA definition of a small appliance? - ✔✔Appliances typically charged at the factory with five pounds or less of refrigerant. Refrigerators and freezers designed for home use, room air conditioners,
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? - ✔✔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? - ✔✔No. May the nitrogen used for purging or pressurizing a system be vented to the atmosphere? - ✔✔Yes. When may a technician recover only 80% of the refrigerant in a small appliance? - ✔✔In a system dependent recovery with a non-operating compressor? May a technician use a passive recovery machine for recovery from a domestic refrigerator? - ✔✔Yes. What requirements are placed on recovery machines built after November 15 1993? - ✔✔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? - ✔✔80%, 90%. Is a certified technician responsible for future changes in EPA regulations? - ✔✔Yes. What type of certification is required to purchase CFC and HCFC refrigerants? - ✔✔Type 1. What must be done with any regulated refrigerant vented from a graduated charging cylinder? - ✔✔It must be recovered. What first step must you always take before starting a recovery of refrigerant form any equipment? - ✔✔Check which refrigerant is being used.
What is a "system-dependent" recovery machine? - ✔✔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. - ✔✔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? - ✔✔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? - ✔✔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? - ✔✔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? - ✔✔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? - ✔✔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? - ✔✔To speed up refrigerant release from the oil. When should entrapped refrigerant from oil be recovered? - ✔✔Any time oil is removed from a large system and on small appliances when using system dependent recovery with a non-operating compressor.
What should be done to a piercing type Schrader valve after it is installed on a charged system? - ✔✔It should be capped after any service procedure. Why should solder-less type piercing valves be removed after completion of repairs? - ✔✔To prevent leaks. What are the critical maintenance checks done to a Schrader valve? - ✔✔Periodically checked for leaks and replaced if damaged. What does a pungent odor detected after opening a system mean? - ✔✔It might mean acids are present due to a compressor burnout. What do you do if the oil is contaminated? - ✔✔Tubing flushing might be required. What system pressure would indicate a recovery should not be performed? - ✔✔0 PSIG. What are the current methods used to monitor the 80% fill level in a recovery tank? - ✔✔Floats, thermistor-type sensors and weighing scales. Why do large refrigerant leaks cause suffocation? - ✔✔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? - ✔✔Self contained breathing apparatus. What should be done if a large leak occurs and no breathing apparatus is available? - ✔✔Ventilate the space and leave the area. Which acids are formed when refrigerant touches sources of high heat? - ✔✔Hydrochloric and hydrofluoric acids and phosgene gas.
What safety component must be used whenever dry nitrogen is used to pressurize a system? - ✔✔Nitrogen tanks should be equipped with a regulator. What information does DOT require when shipping refrigerant cylinders? - ✔✔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? - ✔✔Department of Transportation (DOT). What component is always replaced after a a system is opened for service? - ✔✔Filter-driers. What is the purpose of the moisture indicator in a sight glass? - ✔✔To permit a check of moisture content in the system. What does "back-seating" a suction valve do? - ✔✔Allows flow through the main line while closing the access port. What will non-condensables do to the pressures in a refrigerant circuit? - ✔✔Increase discharge pressure. What causes oil foaming in a system and where does it normally occur? - ✔✔Oil that is mixed with refrigerant will foam in the compressor crankcase. What system failures require taking an oil sample? - ✔✔Compressor burnout or if the unit has had a leak. A vacuum pump that is too large can cause what problem? - ✔✔It can cause moisture to freeze in the system. Where is a receiver typically installed on a system? - ✔✔At the outlet of the condenser.
What is the purpose of a compressor heater? - ✔✔To reduce the amount of refrigerant in the lubricating oil. How is moisture remaining from an evacuation removed from the refrigerant in a system? - ✔✔By the filter-drier. What is the preferred method of leak checking a built-up system prior to charging? - ✔✔Bubble solution. What would a technician initially look for during a visual inspection of a leaking hermetic system? - ✔✔Stains around tubing and fittings. What is typically indicated by excessive superheat on a high-pressure system? - ✔✔Undercharged system, possibly the result of a leaky system. Which refrigerant should be used for a trace charge during leak detection? - ✔✔R-22. How do you leak check an HFC-134a system with a partial charge (no HFC-134a detector available)? - ✔✔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? - ✔✔For a visual check for leaks. Shaft seals on an open type compressor are susceptible to what failures? - ✔✔Refrigerant leaks. What leak rate is permissible on industrial and process refrigeration? - ✔✔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? - ✔✔Less than 15% annually.
What is the easiest way to check the type of refrigerant used in a packaged rooftop system? - ✔✔By the equipment data plate. Refrigerant will recover fastest in which phase liquid or vapor? - ✔✔Liquid. Which refrigerant line should a recovery machine be attached to in order to recover liquid refrigerant from a system? - ✔✔To the liquid line. After a liquid recovery what must be done with the vapor still in the system? - ✔✔A vapor recovery must be performed. Recovering in a vapor phase reduces unwanted loss of what? - ✔✔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? - ✔✔Cooled. What must be done to a recovery machine when changing to a different refrigerant? - ✔✔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? - ✔✔Oil. Recovered refrigerant can contain oil and acids. Name another compound found in refrigerants? - ✔✔Moisture. What is the water source for a condensing coil on a water-cooled recovery machine? - ✔✔Municipal water tap. What access location should you use when recovering from an air cooled system with its condenser several feet above the evaporator? - ✔✔Suction line.
