Epa 608 Study Guide Download

1. Epa 608 Study Guide Download Pdf
2. Epa 608 Study Guide Download Free
3. Epa 608 Certification Study Guide

Details Title Description Total Cards Subject Level Created

Click here to study/print these flashcards. Create your own flash cards! Sign up here. Additional Mechanical Engineering Flashcards

Special Epa 608 Certification Study Guide Ro- – Epa 608 Certification Study Guide Regular 100 [ Epa 608 Certification Study Guide En Espanol Ya-9403 Through the thousands of photographs on the net with regards to epa 608 certification study guide We all choices the top choices with best resolution simply for you and this images is among. EPA 608 Certification Study Guide. This study guide is intended to help the user prepare for the EPA 608 Technician Certification Examination and contains all the information required to.

Cards Return to Set Details

Epa 608 Study Guide Download Pdf

Epa 608 Study Guide Download Free

Epa 608 Certification Study Guide

Term What are the typical uses of the center port of gauge set?	Definition Used during evacuation, charging and recovery procedures.
Term What color are the gauges on a manifold gauge set?	Definition Low pressure is blue, High pressure is red.
Term What are the typical ranges of pressure measurements used on the gauges of a manifold gauge set?	Definition High side is 0 to 500 PSIG; Low side is 0 to 350 PSIG and 0 to 30 in. Hg below atmospheric pressure.
Term Is the refrigerant leaving a condenser at a high or low pressure? Is it a liquid or a gas?	Definition High pressure, liquid.
Term Is the refrigerant entering the expansion valve (variable metering device) a liquid or gas?	Definition Liquid, high pressure.
Term Is the pressure of the refrigerant entering the compressor high or low?	Definition Low pressure vapor.
Term Where in a refrigerant circuit does a liquid boil to absorb heat?	Definition In the evaporator.
Term The refrigerant in the suction line is a gas that has been heated above its saturation. What is this condition called?	Definition Superheated vapor.
Term What can cause liquid refrigerant to migrate to a compressor crankcase?	Definition If the compressor is located in the coldest location in the circuit.
Term List two conditions that can quickly damage a compressor that is starting to run?	Definition Operating while in a deep vacuum or when the service valves are closed.
Term What system failures require taking an oil sample?	Definition A compressor burnout or if the unit has had a leak.
Term Is flushing with refrigerant an acceptable tube cleaning method?	Definition No.
Term In addition to preventing and repairing leaks, what else should a technician do to conserve refrigerant?	Definition Recover and recycle used refrigerants.
Term What factors affect the speed of an evacuation?	Definition 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.
Term How should gauge set hoses be sized for use in evacuating a system?	Definition Use the shortest length and the largest diameter possible for the quickest evacuation. At least as large as the vacuum pump inlet.
Term When evacuating, what is the benefit of using short hoses with large diameters?	Definition Reduces emissions, pressure drop and evacuation time.
Term which connection determines the preferred size of hoses used with a vacuum pump?	Definition The vacuum pump inlet.
Term As the capacity and suction hose size increase, what happens to the time needed for an evacuation?	Definition Time is reduced.
Term What purpose is served by heating a system during dehydration?	Definition To speed up moisture removal.
Term Does a thorough evacuation remove moisture from a system?	Definition Yes.
Term What can happen to oil in the compressor if the moisture is left in an operating system?	Definition The oil will form hydrofluoric and hydrochloric acids which will corrode the internal parts of the system.
Term What is the result of over-evacuating a system?	Definition No damage will be done.
Term How can a system be leak checked using a low pressure gauge?	Definition Vacuum reading will rise when vacuum pump is turned off.
Term How close should the vacuum gauge be connected to the vacuum pump during evacuation?	Definition As far away as possible.
Term When measuring the vacuum of a system being evacuated, the system must be isolated. What must be done to the vacuum pump?	Definition Turn it off and valve it off.
Term What is ozone?	Definition 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.
Term How much ozone can a chlorine atom destroy in the stratosphere?	Definition One atom can destroy 100,000 ozone molecules.
Term What is Ozone Depletion Potential (ODP)?	Definition The ability of any chemical to deplete the ozone layer.
Term What is CFC?	Definition Chlorofluorocarbon.
Term Which refrigerants are CFC's?	Definition R-11,12,113,114.
Term Which chemical in the CFC refrigerants does the most damage to the ozone layer?	Definition Chlorine.
Term What is an HCFC?	Definition Hydrochlorofluorocarbons.
Term Which refrigerants are HCFC's?	Definition R-22,123.
Term Which is more harmful to the ozone layer, a CFC or an HCFC?	Definition CFC's.
Term What is it about CFC's that make them more harmful to the stratosphere?	Definition Chemical strength, they will not breakdown in the lower atmosphere.
Term What is an HFC?	Definition A fluorocarbon that contains no chlorine.
Term Which refrigerants are HFC's?	Definition R-134a,404a,407c,410a.
Term What is the ODP of the HFC refrigerant?	Definition Zero.
Term Which refrigerants contain chlorine?	Definition CFC's and HCFC's.
Term Which refrigerants have high ODP?	Definition CFC's.
Term Which refrigerants have low ODP?	Definition HCFC's, HFC's are zero.
Term What is an azeotrope refrigerant?	Definition A mixture of two or more compounds where the mixture behaves like a single chemical.
Term Is one of the components of R-500 a CFC?	Definition Yes
Term Does stratospheric ozone help or hurt the work of the earth's protective shield?	Definition It helps.
Term What chemical in the stratosphere tells us ozone depletion is occurring?	Definition Chlorine-monoxide.
Term How do we know the chlorine in the stratosphere is coming from CFC's?	Definition The increase in chlorine and fluorine present in the stratosphere, matches the increase in emissions of CFC's.
Term How do we know CFC's get to the stratosphere?	Definition From high altitude air sampling measurements.
Term What role does the ozone layer play in protecting the earth?	Definition It blocks much of the harmful ultraviolet radiation (uv-b).
Term What are the effects on health from increased ultraviolet radiation?	Definition Skin cancer, cataracts, human immunity is reduced.
Term What are the effects on the environment?	Definition Timber growth is reduced, crop yields lowered, marine life and the food chain are impaired.
Term Is ozone depletion a problem for the United States only or a global problem?	Definition A global problem.
Term What is the Montreal Protocol?	Definition A treaty that called for the reduction of production of CFC's.
Term The Montreal Protocol calls for the regulation of what chemicals?	Definition Ozone depleting compounds, CFC's, HCFC's, and Halons.
Term On what date was the production and importation of all CFC's phased out?	Definition In the U.S., after December 31, 1995.
Term Where will we get replacements?	Definition Through recovery of existing refrigerants.
Term What steps are called for by the Clean Air Act?	Definition Taxes on production and use, standards set for the recovery of refrigerants.
Term What is prohibited by the Clean Air Act?	Definition Venting.
Term Do state and local laws have priority over federal law? Can they be less strict?	Definition No. Cities or states can create their own laws but they must be at least as strict as federal laws.
Term 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?	Definition Allows states and municipalities to create their own laws to prevent and monitor the release of CFC and HCFC materials into the atmosphere.
Term By recovering refrigerants, we ensure adequate supplies and prevent venting. What else does the recovery of refrigerants accomplish?	Definition Prevents stratospheric ozone depletion.
Term The Clean Air Act phases out CFC/HCFC production and prohibits venting. What else does it require?	Definition Standards to be set for recovery of all refrigerants prior to appliance service and disposal.
Term 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?	Definition Knowingly venting CFC's, HCFC's and their substitutes.
Term Which refrigerants must be recovered prior to opening a system?	Definition All refrigerants as of 11-15-1995.
Term What releases of a CFC and HCFC are violations of the Clean Air Act?	Definition Any knowingly vented refrigerants.
Term On what date did it become illegal to vent CFC and HCFC refrigerants?	Definition July 1, 1992.
Term Which appliances are covered by Section 608?	Definition Any device which contains and uses a class 1 or class 2 substance as a refrigerant and is used for household or commercial purposes.
Term What is the primary reason the EPA requires a service aperture or process stub on all appliances?	Definition For adding or removing refrigerant from the appliance.
Term Who sets the regulations for recovery machines?	Definition EPA.
Term What is a 'self-contained' recovery machines?	Definition A recovery machine that has its own compressor to pump refrigerant out of the system.
Term Is HCFC-123 a 'low or 'high' pressure refrigerant?	Definition Low pressure.
Term Is CFC-12 a 'low' or 'high' pressure refrigerant?	Definition High pressure.
Term What is the smallest container in which refrigerants may be sold to a Section 608 certified technicians.	Definition 20 pounds.
Term What must you do to the refrigerant in an appliance before disposing of the appliance?	Definition Recover refrigerant or verify that the refrigerant was previously recovered.
Term Who is responsible for removing the refrigerant from household refrigerators prior to disposal?	Definition The final person in the disposal chain. (Scrap metal recyclers, landfill owner, etc)
Term What is the penalty for violation of the Clean Air Act?	Definition Fines up to $27,500 per violation per day and possible loss of technician certification.
Term How much is the bounty for information leading to a conviction?	Definition Up to $10,000.
Term What ca happen if a technician cannot demonstrate an ability to use recovery or recycling equipment?	Definition May result in revocation of the technician's certification.
Term What is the name of the process that removes refrigerant from a system and stores it without testing or processing?	Definition Recovery.
Term What is the name for the process that removes moisture and acids from refrigerant but does not test the refrigerant?	Definition Recycling.
Term What is the name for the process that removes moisture and acids from refrigerant and also chemically tests the refrigerant?	Definition Reclaim.
Term What must be done with reclaimed refrigerant before it can be legally resold?	Definition Chemically tested to ARI Standard 700, the purity level of factory new refrigerant.
Term What is the preferred instrument for detecting small leaks?	Definition Electronic leak detector and Ultrasonic detector.
Term What is an inert gas typically used in leak detection?	Definition Dry nitrogen.
Term What is typically indicated by a dehydrated system failing to hold a vacuum?	Definition Leaks.
Term What should be done when recovering the refrigerant form a system where the refrigerant has been improperly mixed?	Definition Recover into a separate container?
Term Can mixed refrigerants be reclaimed?	Definition No.
Term What precautions should be taken when recovering refrigerant from systems with multiple service valves?	Definition Insure that liquid is not trapped between service valves.
Term What is the effect of low ambient temperature on the time required to complete a recovery of refrigerant?	Definition Increases recovery time.
Term Technicians must explain to customers that recovery is necessary and it is required by law. What else should the technician tell the customer?	Definition That all service personnel are duty bound to follow the law and protect the environment.
Term What is different about any leaks in systems charged with a blended refrigerant?	Definition Because they are blended, the ingredients will leak at different rates.
Term What is 'temperature glide'?	Definition A family of lines depicting pressure versus temperature curve.
Term What is ternary blend?	Definition A blend of three different refrigerants.
Term How should systems using blended refrigerants be charged?	Definition In liquid form into the high side of the system.
Term Is there a 'drop-in' refrigerant for CFC-12?	Definition No.
Term How do you leak check an HFC-134a system with a partial charge (no HFC-134a detector available)?	Definition 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.
Term What is the preferred oil to be used with HFC-134a?	Definition Ployolester.
Term Can ester based oils be mixed with other oils?	Definition No.
Term What does 'hygroscopic' mean?	Definition Oil that absorbs moisture easily.
Term What lubricant is recommended for use with a ternary blend?	Definition Depends on the blend: For HCFC's-Alkylbenze, For HFC's-Ployolester.
Term Safety glasses and butyl-lined gloves should be worn for what procedures?	Definition When operating recovery or recycling devices and when handling and refilling refrigerant cylinders.
Term What safety component must be used whenever dry nitrogen is used to pressurize a system?	Definition Pressure regulator.
Term 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?	Definition All of them.
Term What is a Material Safety Data Sheet?	Definition A sheet the states the safety ratings and precautions to be taken for use and handling of chemicals.
Term What safety classification within the ASHRAE standard is the most safe?	Definition A1.
Term What is caused by tie inhaling of refrigerant vapors?	Definition Heart irregularities or Asphyxia.
Term What is the major causes of death involving refrigerants?	Definition Oxygen deprivation.
Term What breathing problem can be caused by CFC-12?	Definition Asphyxia.
Term How can ice be removed from a sight glass?	Definition With alcohol spray.
Term What must be done with a badly corroded relief valve?	Definition It must be replaced.
Term Where can you find the allowable test pressure on a system?	Definition Unit data plate.
Term Can oxygen be used to check for leaks? If not, why not?	Definition No. Oxygen in the presence of oil under high pressure can be explosive.
Term What is the likely result of heating a recovery cylinder with an open flame?	Definition Refrigerant will decompose into a toxic material, venting of refrigerant int the atmosphere or the tank may explode.
Term What is the primary purpose of a disposable cylinder?	Definition For virgin refrigerant from the manufacturer.
Term To what internal pressure should a disposable cylinder be reduced to for disposal?	Definition Reduced to at least 0 PSIG.
Term Should you ever use a disposable cylinder for refrigerant recovery?	Definition No.
Term 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?	Definition Puncture the container before disposal.
Term For safety, refrigerant chlinders should not be rusted or damaged and always properly color coded. What additional step should also be taken with these cylinders?	Definition Properly secured at all times.
Term What is the proper color code for recovery cylinders?	Definition Gray with a yellow top.
Term What is the maximum percent by weight that a cylinder may be filled?	Definition 80%.
Term What can happen if a cylinder is overfilled?	Definition Hydrostatic pressure could cause the cylinder to explode.
Term List three methods for measuring the fill level of a recovery cylinder.	Definition Floats, thermistor type sensors, and weighing scales.
Term Wow often must reusable cylinders be hydrostatically tested?	Definition Every five years.
Term Why must only refillable cylinders be used for transport?	Definition Federal code of regulations title 49 (parts 100-177) states this.
Term What must be affixed to a refrigerant cylinder prior to its shipment to a reclaimer?	Definition DOT classification tag.
Term What is the purpose of a DOT classification tag?	Definition For transportation purposes.
Term What is the correct shipping position for a refrigerant cylinder?	Definition In a vertical or upright position with their valves at the top.
Term What is the EPA definition of a small appliance?	Definition 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.
Term Does the EPA require the repair of leaks on small appliances?	Definition Repair of leaks on small appliances is not required, but leaks should be repaired whenever possible.
Term What EPA certification type must technicians have to service any appliance that EPA calls a 'small appliance?'	Definition Type 1 or Universal.
Term What service aperture may be used on small appliance?	Definition Access tubes or process tubes.
Term 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?	Definition Low-loss fitting. (shut-off valve)
Term What is the primary purpose for using hand valves or self-sealing hoses when using a gauge set?	Definition To prevent loss of refrigerant.
Term Which refrigerants must be recovered under Section 608 of the EPA regulations?	Definition CFC, HCFC and HFC refrigerant.
Term Is there a 'drop-in' refrigerant for CFC-12?	Definition No.
Term What is the replacement refrigerant for CFC-12 in household refrigerators?	Definition HFC-134a.
Term What can be determined by taking an accurate temperature and pressure reading of a container holding a recovered refrigerant?	Definition Check for non-condensables and the type of refrigerant.
Term When doing a non-condensables check, a recovery cylinder should stabilize in temperature before any readings are taken. Why?	Definition To find the correct pressure for that temperature on a T/P chart.
Term What is the internal pressure of CFC-12 refrigerant stored at 75 deg. F?	Definition 77 PSIG.
Term 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?	Definition Only when the person is working on a small appliance.
Term 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?	Definition No.
Term May the nitrogen used for purging or pressurizing a system be vented to the atmosphere?	Definition Yes.
Term When may a technician recover only 80% of the refrigerant in a small appliance?	Definition In a system dependent recovery with a non-operating compressor?
Term May a technician use a passive recovery machine for recovery from a domestic refrigerator?	Definition Yes.
Term What requirements are placed on recovery machines built after November 15, 1993?	Definition 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.
Term 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?	Definition 80%, 90%.
Term Is a certified technician responsible for future changes in EPA regulations?	Definition Yes.
Term What type of certification is required to purchase CFC and HCFC refrigerants?	Definition Type 1.
Term What must be done with any regulated refrigerant vented from a graduated charging cylinder?	Definition It must be recovered.
Term What first step must you always take before starting a recovery of refrigerant form any equipment?	Definition Check which refrigerant is being used.
Term What is a 'system-dependent' recovery machine?	Definition 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.
Term Describe a system-dependent (passive) recovery process for small appliances.	Definition 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.
Term What two conditions require that you access both the high and low side of the system for refrigerant recovery?	Definition When there is an inoperative compressor on the system or when necessary to reach required recovery levels.
Term What are the benefits of accessing the low and high side access valves when recovering refrigerant from a system with an inoperative compressor?	Definition It speeds up recovery, improves efficiency and may be necessary to reach required recovery levels.
Term 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?	Definition Access the high side and run the compressor.
Term Which access valve (s) should you connect to when recovering from a system with an operating compressor and a completely restricted capillary tube?	Definition High side valve.
Term When using a self-contained (active) recovery device, what two conditions can cause excessive pressure on the recovery machine's high side?	Definition A recovery container that is not properly evacuated or one that has unopened valve.
Term Why should defrost heaters be turned on during a recovery from a small appliance?	Definition To speed up refrigerant release from the oil.
Term When should entrapped refrigerant from oil be recovered?	Definition Any time oil is removed from a large system and on small appliances when using system dependent recovery with a non-operating compressor.
Term What does striking the appliance compressor do during a recovery?	Definition Helps to free refrigerant that may be trapped in the oil.
Term A recovery machine should be checked daily for what?	Definition Refrigerant leaks.
Term Can a standard vacuum pump be used as a recovery machine?	Definition 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.
Term Should technicians ever mix refrigerants in the field?	Definition No.
Term How should you recover refrigerant that is different from the refrigerant you usually recover?	Definition Different refrigerants must be placed in recovery vessels containing the same type of refrigerant.
Term What can a reclaimer do with any mixed refrigerant you ship to them?	Definition They may either refuse to process and return it at owner's expense or agree to destroy the refrigerant for a substantial fee.
Term To ship recovered refrigerant you must label the container and complete all necessary paperwork. What else should you do?	Definition Use DOT approved cylinders.
Term What federal agency sets the standards for portable refillable tanks or containers used to ship CFC or HCFC refrigerants?	Definition Department of Transportation (DOT).
Term Safety glasses and butyl-lined gloves should be worn fro what procedures?	Definition When you are connecting and disconnecting hoses.
Term Piercing valves are used for what purpose?	Definition To allow access to the sealed system for recovery.
Term On what materials are piercing valves used?	Definition Copper or aluminum refrigerant lines.
Term What should be done to a piercing type Schrader valve after it is installed on a charged system?	Definition It should be capped after any service procedure.
Term Why should solder-less type piercing valves be removed after completion of repairs?	Definition To prevent leaks.
Term What are the critical maintenance checks done to a Schrader valve?	Definition Periodically checked for leaks and replaced if damaged.
Term What does a pungent odor detected after opening a system mean?	Definition It might mean acids are present due to a compressor burnout.
Term What do you do if the oil is contaminated?	Definition Tubing flushing might be required.
Term What system pressure would indicate a recovery should not be performed?	Definition 0 PSIG.
Term What are the current methods used to monitor the 80% fill level in a recovery tank?	Definition Floats, thermistor-type sensors and weighing scales.
Term Why do large refrigerant leaks cause suffocation?	Definition Refrigerants will replace air in a confined space leading to possible oxygen starvation.
Term Before entering an area of a large leak of refrigerant what apparatus must be worn?	Definition Self contained breathing apparatus.
Term What should be done if a large leak occurs and no breathing apparatus is available?	Definition Ventilate the space and leave the area.
Term Which acids are formed when refrigerant touches sources of high heat?	Definition Hydrochloric and hydrofluoric acids and phosgene gas.
Term What safety component must be used whenever dry nitrogen is used to pressurize a system?	Definition Nitrogen tanks should be equipped with a regulator.
Term What information does DOT require when shipping refrigerant cylinders?	Definition Shipping papers must indicate the refrigerant type and number of cylinders.
Term Which government agency sets the standards for refillable refrigerant cylinders used to transport CFC and HCFC refrigerants?	Definition Department of Transportation (DOT).
Term What component is always replaced after a a system is opened for service?	Definition Filter-driers.
Term What is the purpose of the moisture indicator in a sight glass?	Definition To permit a check of moisture content in the system.
Term What does 'back-seating' a suction valve do?	Definition Allows flow through the main line while closing the access port.
Term What will non-condensables do to the pressures in a refrigerant circuit?	Definition Increase discharge pressure.
Term What causes oil foaming in a system and where does it normally occur?	Definition Oil that is mixed with refrigerant will foam in the compressor crankcase.
Term What system failures require taking an oil sample?	Definition Compressor burnout or if the unit has had a leak.
Term A vacuum pump that is too large can cause what problem?	Definition It can cause moisture to freeze in the system?
Term Where is a receiver typically installed on a system?	Definition At the outlet of the condenser.
Term What will be the boiling temperature of HFC-134a be at 0 PSIG?	Definition -15 degrees F.
Term Is it a requirement that recovery machines contain an oil separator?	Definition No.
Term Which refrigerant is typically used on a residential split system air conditioner?	Definition HCFC-22.
Term Is the refrigerant leaving a receiver a liquid or a gas? Is it at a high or low pressure?	Definition Liquid, high pressure.
Term What is the initial charging method of a system when the charge is specified at 70 pounds?	Definition Charged in liquid state.
Term Is the receiver on the high or low side of a system?	Definition High side.
Term What is the minimum recommended capability (measured in microns) of a vacuum pump used for evacuations?	Definition Should pull a vacuum of 500 microns.
Term What is the pressure of a CFC-12 machine at 72 deg. F while the machine is idle?	Definition 73 PSIG.
Term What is the preferred unit of measurement for checking a deep vacuum?	Definition Microns.
Term Where is an accumulator located in a refrigeration system?	Definition On the suction line before the compressor.
Term To prevent freezing of any moisture in a CFC-12 system, vapor should first be charged until the pressure is at what level?	Definition 33 PSIG
Term What gas should be used during an evacuation to increase pressure to prevent freezing?	Definition Dry nitrogen.
Term What is the purpose of a compressor heater?	Definition To reduce the amount of refrigerant in the lubricating oil.
Term How is moisture remaining from an evacuation removed from the refrigerant in a system?	Definition By the filter-drier.
Term What is the preferred method of leak checking a built-up system prior to charging?	Definition Bubble solution.
Term What would a technician initially look for during a visual inspection of a leaking hermetic system?	Definition Stains around tubing and fittings.
Term What is typically indicated by excessive superheat on a high-pressure system?	Definition Undercharged system, possibly the result of a leaky system.
Term Which refrigerant should be used for a trace charge during leak detection?	Definition R-22.
Term How do you leak check an HFC-134a system with a partial charge (no HFC-134a detector available)?	Definition Recover remaining 134a, pressurize the system with nitrogen and a trace charge of R-22 so you can use an HCFC electronic leak detector.
Term For what purpose are soap bubbles used in leak checking?	Definition For a visual check for leaks.
Term Shaft seals on an open type compressor are susceptible to what failures?	Definition Refrigerant leaks.
Term What leak rate is permissible on industrial and process refrigeration?	Definition 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.
Term What leak rate is permissible on equipment (other than industrial or process equipment) that contains more that 50 lbs. of refrigerant?	Definition Less than 15% annually.
Term What is the easiest way to check the type of refrigerant used in a packaged rooftop system?	Definition By the equipment data plate.
Term Refrigerant will recover fastest in which phase, liquid or vapor?	Definition Liquid.
Term Which refrigerant line should a recovery machine be attached to in order to recover liquid refrigerant from a system?	Definition To the liquid line.
Term After a liquid recovery, what must be done with the vapor still in the system?	Definition Vapor recovery bust be performed.
Term Recovering in a vapor phase reduces unwanted loss of what?	Definition Oil and unwanted contaminants from the system to the recovery machine and recovery drum.
Term On a high pressure system recovery, should the recovery cylinder be heated or cooled?	Definition Cooled.
Term What must be done to a recovery machine when changing to a different refrigerant?	Definition Clean out all residual refrigerant, change oil, replace filters, evacuate machine by pump-out or another machine.
Term What besides filters must periodically be changed out on a recovery machine?	Definition Oil.
Term Recovered refrigerant can contain oil and acids. Name another compound found in refrigerants?	Definition Moisture.
Term What is the water source for a condensing coil on a water-cooled recovery machine?	Definition Municipal water tap.
Term What access location should you use when recovering from an air cooled system with its condenser several feet above the evaporator?	Definition Suction line.
Term What access location should you use when recovering from a system with its condenser below the evaporator?	Definition Liquid line.
Term Before using a recovery unit, the technician should check service valve positions and check the recovery unit oil level. What additional step must be taken?	Definition All solenoid valves should be open.
Term What is the primary purpose for using hand valves or self-sealing hoses when using a gauge set?	Definition To prevent loss of refrigerant when connecting and disconnecting hoses.
Term What can cause recovery equipment with a hermetic compressor to overheat when drawing a deep vacuum?	Definition No airflow over the compressor body or no suction gas flow over the internal motors, or a combination of the two.
Term What is the reason for not operating a hermetic refrigeration compressor while it is in a deep vacuum?	Definition To prevent overheating the compressor motor.
Term What is the reason for not starting a reciprocating compressor with its discharge service valve closed?	Definition To prevent overheating the compressor motor.
Term When can a 'system-dependent' recovery device be used?	Definition 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.
Term What vacuum level must you reach when recovering from a system with 38 pounds of R-502 using a recovery machine manufactured in 1995?	Definition 10 inches of Hg.
Term What is EPA's definition of a 'major repair'?	Definition Any repair that involves the removal of the compressor, evaporator, condenser, or any auxiliary heat exchanger coil.
Term 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?	Definition 15 inches of Hg.
Term What vacuum level must you pull when using recovery equipment manufactured in 1992 when disposing of an appliance containing 12 lbs. of R-500?	Definition 4 inches of Hg.
Term Under what circumstances may a technician recover the CFC refrigerant in an appliance to atmospheric pressure only?	Definition if leaks are in the system or if recovery to target levels would contaminate the refrigerant.
Term What procedure should be performed on an empty recovery cylinder before it is used for storing recovered refrigerant?	Definition It must be evacuated of all non-condensables.
Term What may legally be done with the refrigerant recovered from a system in order to replace a condenser coil?	Definition 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.
Term When servicing an operating unit with a receiver, where should the recovery hoses be attached to the unit?	Definition To the liquid line.
Term In order to recover from a system with parallel compressors, the individual compressors must be isolated. Why?	Definition It isolates the refrigerant that must be recovered from the rest of the system.
Term Which refrigerant (s) require and equipment room monitor per ASHRAE Standard 15?	Definition All refrigerants.
Term What protection is mandatory to protect a system against damage from excessive pressure?	Definition A pressure relief device.
Term Are multiple relief valves connected in series or parallel?	Definition Parrallel.
Term Why is the use of a regulator required when using dry nitrogen?	Definition To limit the outlet pressure of the nitrogen cylinder.
Term How can ice be removed from a sight glass?	Definition Cleaned with an alcohol spray.
Term How high should you pressurize an idle low pressure chiller to prevent air accumulation?	Definition Slightly above atmospheric pressure.
Term What effect does air in a chiller have on head pressure?	Definition Raises head pressure.
Term What system failures require taking and oil sample?	Definition A leak or major component failure (compressor burnout).
Term Why must water be circulated through a chiller during refrigerant recovery?	Definition To prevent freeze-up of the water as pressure is reduced on the refrigerant.
Term What is the lowest access valve on a low pressure chiller?	Definition The evaporator charging valve.
Term Where is a centrifugal chiller's rupture disk attached?	Definition At the evaporator.
Term What is the typical pressure setting for a low pressure chiller's rupture disk?	Definition 15 PSIG.
Term Where is the outlet of a rupture disk discharged?	Definition Outdoor for venting.
Term How is a chiller typically charged?	Definition Liquid through the evaporator charging valve.
Term What minimum saturation temperature needs to be achieved before liquid is charged into a chiller?	Definition Above freezing, typically 36 deg. F.
Term To prevent freezing of water when charging a chiller, what pressure should be reached with vapor before using liquid CFC-11?	Definition 16.9 inches of Hg.
Term What could result from liquid refrigerant being charged into a chiller that is holding a 29 inch Hg. vacuum?	Definition Can cause system water to freeze.
Term What function is served by a purge unit on a chiller?	Definition Minimize the effects of contamination. To remove non-condensables.
Term What is the most likely cause of air leaks into a chiller refrigerant circuit?	Definition Gaskets and fittings.
Term How is a purge unit connected on a low pressure chiller?	Definition The inlet of the purge unit is typically connected to the top of the condenser.
Term Where is the suction of a purge unit connected?	Definition The inlet of the purge unit is typically connected to the top of the condenser.
Term What is a high efficiency purge unit?	Definition It removes non-condensables that contain a low percentage of refrigerant. This adds to the value of the purge drum in refrigerant containment.
Term Shaft seals on an open type compressor are susceptible to what failures?	Definition Refrigerant leaks.
Term Purge units work best when they are not needed. How can purge unit operating time be reduced?	Definition By regular leak checking and repairing any leaks on a regular schedule.
Term What is the maximum pressure that can be used when leak checking a low pressure chiller?	Definition 10 PSIG on low pressure equipment that utilizes a rupture disk.
Term What is the preferred method of leak checking a charged low pressure chiller?	Definition By increasing the refrigerant pressure using an external heat source or running hot water through the chiller tubes not to exceed 10 PSIG.
Term Where should you check for leaks between a chiller refrigerant tube and the water box?	Definition The chiller barrel can be emptied of all water and a leak check can be made at the drain valve with the water off. If the tubes themselves require a leak check, the check can be made with a hydrostatic tube test kit.
Term What is a hydrostatic tube test kit used for?	Definition To check for leaks in a chiller tubes.
Term What leak rate is permissible on industrial and process refrigeration?	Definition Effective 6/14/93, any annualized leak rate of 35% or more on equipment with 50 lbs. of charge or more must be repaired. Less than 35% is permissible.
Term What leak rate is permissible on equipment other than industrial and process equipment?	Definition For appliances with 50 lbs. of charge or more an annual leak rate of 15% or more must be repaired. Less than 15% leak rate is permissible.
Term According to ASHRAE 3-1990, what rise is permitted in vacuum level during a standing vacuum test?	Definition Starting at 1mm of Hg., after 12 hours the vacuum reading should not increase to more than 2.5 mm of Hg.
Term List two steps to reduce the run time of a purge unit.	Definition Regular leak checks and repair any leaks.
Term Why should the water side of the evaporator and condenser be drained before recovering refrigerant from a chiller suspected of having tube leaks?	Definition To prevent moisture form being drawn into the refrigerant circuit.
Term If a purge unit is operating excessively, what problem can you expect to find?	Definition Leaks.
Term What condition would cause continuous excessive moisture collection in the purge unit of a low pressure refrigeration system?	Definition Leaks between the refrigerant circuit and the water circuit.
Term Why should oil be warmed prior to removal from a low pressure chiller?	Definition To vaporize any liquid refrigerant that might be trapped in the oil.
Term After liquid recovery, what must be done with the vapor still in the system?	Definition Vapor recovery must be performed.
Term Is recovery of refrigerant from a low pressure appliance typically started with liquid or vapor?	Definition Start with liquid removal.
Term Where is the connection made for the water supply used on a water cooled recovery unit?	Definition Local water supply.
Term What should be the maximum pressure on the discharge of a recovery machine for low pressure systems?	Definition 10 PSIG, because the rupture disk is set to open at 15 PSIG.
Term What should be done with the water pumps during a recovery form a low pressure chiller?	Definition
Term What is EPA's definition of a 'major repair'?	Definition Any repair that involves the removal of the compressor, evaporator, condenser, or any auxiliary heat exchange coil.
Term What recovery vacuum must be met on a low pressure appliance using a machine built in 1992?	Definition 25 inches of Hg.
Term Why should you wait a few minutes after reaching the required recovery vacuum on an appliance to see if pressure rises?	Definition To see if refrigerant is still trapped in the system.
Term Under what circumstances may the recovery from an appliance be stopped without reaching the prescribed level?	Definition If the recovery would contaminate the refrigerant being recovered. (this level cannot exceed 0 PSIG.)
Term Is it a requirement that recycling and recovery equipment be capable of handling more than one refrigerant?	Definition No.
Term Is it permissible to warm the refrigerant under EPA's regulations to pressurize a low pressure system to do a non-major repair?	Definition Yes.
Term What final vacuum level is required for recovering refrigerant from a low pressure system if the technician is using recovery equipment manufactured BEFORE November 15, 1993? AFTER November 15, 1993?	Definition 25 inches of Hg, 25 mm of Hg. Absolute (equal to about 29 inches of Hg.)
Term A vacuum pump that is too large for a particular system can cause what problem?	Definition It can cause moisture to freeze in the system.
Term How can you prevent moisture from freezing during dehydration?	Definition You can raise the pressure with nitrogen and allow the ice to melt, then continue with the evacuation.
Term Are multiple relief valves connected in series or parallel?	Definition Parallel.
Term ASHRAE Standard 15 covers refrigerant level monitoring for what refrigerants?	Definition All refrigerants.
Term According to ASHRAE Standard 15, what is the standard for refrigerant concentration for a machine room that must not be exceeded without activating an alarm and starting ventilation in the machine room?	Definition May not exceed the TLV-TWA. (Threshold limit value-Time weighted average.)
Term List four safety procedures that should be followed when working with liquid low pressure refrigerant.	Definition 1. Use refrigerant sensors in equipment room. 2. Avoid siphoning refrigerant by mouth. 3. Wear butyl-lined gloves. 4. Wear safety glasses.
Term What is the toxicity and flammability rating of HCFC-123 per ASHRAE Standard 34?	Definition B1.