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EPA 608 Type 2
Medium/(very) high pressure practice (may include content from Core & Types 1/3)
| Question | Answer |
|---|---|
| Which of following always falls under EPA definition for major maintenance, service, or repair? | correct answer: replacing compressor incorrect options: replacing oil filter, replacing expansion valve, replacing accumulator |
| Recovering refrigerant from system in vapor phase will minimize loss of which of following? | correct answer: oil incorrect options: water, refrigerant, non-condensables |
| In event of large release of CFC, HCFC, or HFC refrigerant in contained area, which of following is true? | correct answer: self-contained breathing apparatus (SCBA) or leaving area is required incorrect options: safety goggles/butyl lined gloves are sufficient, respiratory protection is not required, dust masks are sufficient |
| Comfort cooling appliance containing 50 pounds or more of R-22 is found to be leaking beyond applicable leak rate threshold. Unless granted additional time, how many days do you have to repair leak and conduct initial leak verification test? | correct answer: 30 days incorrect options: 1 day, 10 days, 45 days |
| What are refrigeration and air conditioning compressor heaters used for? | correct answer: to reduce amount of refrigerant in oil incorrect options: to prevent refrigerant vaporization, to reduce amount of entrained water in receiver, to prevent acid pitting |
| What is characteristic of refrigerant oil that is hygroscopic? | correct answer: it readily absorbs moisture incorrect options: it is good lubricant, it is crude oil and unrefined, it can be left open to ambient air |
| Appliance normally containing more than 50 pounds of R-22 refrigerant was found to have 35% annual leak rate. After repair, how many successful verification tests are required? | correct answer: two, first performed before recharging and second performed after returning to normal operating conditions incorrect options: 1 before recharging, 1 once appliance returns to normal operation, 3 up to 3 months later |
| Which of following should be replaced if system is opened for servicing? | correct answer: filter drier incorrect options: thermostat, metering device, crankcase heater |
| What must system owner do once threshold leak rate has been exceeded on any low pressure system using ozone depleting refrigerant? | correct answer: repair appliance enough to bring leak rate below threshold, retrofit, or retire appliance incorrect options: retire appliance following year, repair all leaks and submit report to EPA, immediately mothball appliance until retrofitted |
| When could reciprocating compressor be damaged if energized? | correct answer: when discharge service valve is closed incorrect options: when suction service valve is open, when discharge service valve is open, when demand for cooling is at steady state |
| Why could recycling or recovery machine that uses hermetic compressor overheat when drawing deep vacuums? | correct answer: motor relies on flow of refrigerant through compressor for cooling incorrect options: runs faster than equipment with oil less compressors, has higher compression ratio limit, oils used in hermetic compressors are lower viscosity |
| Recovered refrigerant may contain which of following impurities? | correct answer: acids, moisture, and oil incorrect options: ammonia/carbon dioxide/methyl chloride, sodium chloride/potassium nitrate/silicone oil, sulphur dioxide and methane |
| After installation of field piped split system, unit should first be pressurized with: | correct answer: nitrogen and leak checked incorrect options: air and leak checked, R-22 and leak checked, R-410A and leak checked |
| Which of following is indicator of possible leak in high pressure system with capillary tube? | correct answer: excessive superheat incorrect options: high head pressure, low water temperature, frequent purging |
| Your recovery/recycling machine has R-22 refrigerant in it. You now have to recover refrigerant from R-410A unit. What must be done before your recovery unit can be used to recover R-410A? | correct answer: remove R-22 from recovery unit and change filter incorrect options: change recovery cylinder on recovery machine, change expansion valve on recovery machine, change filter and expansion valve on recovery machine |
| Which condition can cause excessive pressure on high side of self-contained (active) recovery device? | correct answer: when there is large volume of non-condensable gas in refrigerant being recovered incorrect options: when TXV is stuck open, when capacity of recovery tank is larger than charge size of system, when system is set for no subcooling |
| After refrigerant liquid has been recovered from appliance, any remaining vapor is: | correct answer: removed by recovery system incorrect options: purged to atmosphere, isolated in appliance, pumped into appliance receiver |
| What gas should be used to leak check system designed for use with R-410A that has been opened for major system repair? | correct answer: pressurized nitrogen incorrect options: any available HFC, any available HCFC, compressed air |
| Customer has industrial process refrigeration system that contains 1000 lbs. of R-22 that has exceeded applicable leak rate threshold. How often is customer required to perform leak inspection? | correct answer: every 3 months incorrect options: every month, every 6 months, every 12 months |
| When first inspecting hermetic system known to be leaking, you should look for: | correct answer: traces of oil incorrect options: frost on tubing, puddles of refrigerant, particles of filter drier core |
| Crankcase heater is often used to prevent refrigerant from mixing with compressor oil during periods of: | correct answer: low ambient temperature incorrect options: high ambient temperature, low humidity, high humidity |
| Refrigerant should be recovered from condenser outlet if condenser is: | correct answer: below (liquid) receiver incorrect options: above receiver, on roof, is leaking |
| New split system should be checked for leak by: | correct answer: pressurizing system with few ounces of system refrigerant and inert gas incorrect options: releasing factory refrigerant charge in condensing unit, pressurizing system with few ounces of HCFC-22 and compressed air, CFC-12 and inert gas |
| When using recovery unit on system containing 100 lbs. of R-410A, it must be evacuated to: | correct answer: 0 inches of mercury (vacuum) incorrect options: 4 inches of Hg, 10 inches of Hg, 15 inches of Hg |
| What can be done with refrigerant trace gas and nitrogen mixture after system leak is found? | correct answer: release to atmosphere incorrect options: recover mixture, recover in special recovery tank, recycle refrigerant back into system |
| If leaking appliance with regulated refrigerant is not going to be repaired, it must be: | correct answer: retrofitted or retired within 12 months (top of page 20 in packet) incorrect options: retrofitted or retired within 3 months, replaced within 3 months, replaced within 12 months |
| Non-condensables will cause: | correct answer: high discharge pressure incorrect options: high superheat, low discharge pressure, low superheat |
| Comfort cooling system that contains 50 pounds or more of R-410A is leaking. What will be new maximum allowable annual leak rate starting in 2019? | correct answer: 10% incorrect options: 5%, 20%, 30% |
| Refrigerants CFC-12, HCFC-22, and HFC-134a are all classified as what type of refrigerants? | correct answer: A-1 (found on top of P/T chart) incorrect options: A-2, B-1, B-2 |
| What must equipment owners/operators include in recovered refrigerant records for equipment with refrigerant charges that range from 5 to 50 pounds? | correct answer: quantity of refrigerant by type added or recovered from disposed appliances in each calendar month and quantity of refrigerant by type sent for reclamation or destruction (top of page 10 in packet) incorrect option: seasonal variance |
| When recovering refrigerant from medium pressure system with more than 200 lbs. of refrigerant, recover to level of: | correct answer: 15" Hg (vacuum) incorrect options: 0" Hg, 4" Hg, 10" Hg |
| High pressure appliance containing less than 200 lbs. of HCFC or HFC refrigerant must be evacuated (recovered) to level of: | correct answer: 0 inches of (Hg) vacuum incorrect options: 4 inches of vacuum, 10 inches of vacuum, 15 inches of vacuum |
| High pressure appliance containing 210 lbs. of R-407C refrigerant must be evacuated (recovered) to level of: | correct answer: 10 inches of (Hg) vacuum incorrect options: 0 inches of vacuum, 4 inches of vacuum, 15 inches of vacuum |
| Proper recovery techniques begin with use of appropriate recovery equipment that has been certified by: | correct answer: EPA approved laboratory incorrect options: EPA only, manufacturers approved by UL, EPA field supervisors |
| EPA regulations require that all industrial process refrigeration (IPR) systems containing more than 50 pounds of refrigerant must be repaired when annual leak rate exceeds: | correct answer: 30% incorrect options: 10%, 20%, 40% |
| Leaks must be repaired on industrial process refrigeration units with 50 pound charge or greater when annualized leak rate reaches what level or more? | correct answer: 30% incorrect options: 10%, 20%, 40% |
| EPA regulations state that removal of which component constitutes major repair? | correct answer: compressor incorrect options: pressure switch, liquid line drier, evaporator fan motor |
| When appliance containing 50 pounds or more of regulated refrigerant leaks refrigerant at annual rate of 125% or more, what must be included on leak inspection records? | correct answer: initial verification and follow up verification tests as well as records of recovered refrigerant from equipment incorrect option: quantity of refrigerant sold, procedures performed, date of call, name/address/phone # of manufacturer |
| Refrigerant sensor which will sound alarm and automatically start ventilation system in occupied equipment rooms falls under ASHRAE Standard: | correct answer: 15 incorrect options: 34, 44, 60 |
| Unless plans are made to replace system with leak rate that exceeds maximum leak rate, repairs must be made within: | correct answer: 30 days incorrect options: 45 days, 60 days, 90 days |
| Which of following refrigerants is classified as very high pressure refrigerant? | correct answer: R-744 (found on top of P/T chart) incorrect options: CFC-11, HCFC-123, R-410A |
| When dehydrating (medium or high pressure) system, it should be evacuated to minimum level of: | correct answer: 500 microns incorrect options: 30 inches of mercury, 25,000 microns, EPA does not have requirement |
| What happens to refrigerant that is heated above saturation temperature? | correct answer: remains in vapor state incorrect options: remains in liquid state, absorbs moisture at increased rate, cools compressor more efficiently |
| All HVAC/R systems must be protected by: | correct answer: pressure relief valve incorrect options: low pressure switch, high pressure switch, compressor impedance overload |
| What condition allows for system to be opened and repaired without recovering refrigerant to required vacuum level? | correct answer: system with large leak and internal pressure of 0psig incorrect options: system undergoing major component replacement, system that uses CFC refrigerant, system that has non-operational compressor |
| Heat pumps that use medium or high pressure HFC refrigerant should be leak checked with: | correct answer: pressurized nitrogen incorrect options: HFCs, HFCs to lower cost of discarding refrigerant, compressed oxygen |
| Heat pumps that have been retrofitted from R-22 to R-407C should be leak checked with: | correct answer: pressurized nitrogen incorrect options: HFCs, HCFCs, compressed air |
| To change compressor on system containing R-410A, you must isolate compressor then: | correct answer: evacuate isolated section of system to atmospheric pressure and hold, if system pressure does not rise remove compressor incorrect options: 10 inches of vacuum, 15 inches of vacuum, simply remove compressor |
| Method to charge system that has normal charge of 80 pounds is to charge with: | correct answer: liquid through liquid line service valve incorrect options: vapor through suction line service valve, liquid through discharge service valve, liquid through suction service valve |
| After installation of field piped R-410A split heat pump, unit should first be: | correct answer: pressurized with nitrogen then leak checked incorrect options: evacuated, pressurized with R-22 then leak checked, pressurized with R-410A then leak checked |
| Pressure relief valves must not be: | correct answer: installed in series incorrect options: installed in parallel, installed vertically, installed horizontally |
| When charging R-12 refrigeration system that uses water-cooled condenser, you must first charge with vapor to pressure of at least what before switching to liquid charging? | correct answer: 35 psig (rounded from 32.5psig as corresponding pressure to closest temperature to 36 degrees F on P/T chart for R-12) incorrect options: 0psig, 20psig, 100psig |
| Your recovery/recycling machine has R-22 refrigerant in it. You now have to recover refrigerant from R-410A unit. What must you check before your recovery unit can be used to recover R-410A? | correct answer: all of above (recovery unit must be EPA certified for use with R-410A, recovery tank must be designed for pressure of R-410A, filter and lubricant in recovery unit must be changed and recovery unit evacuated) |
| After reaching required recovery vacuum on system, you must: | correct answer: wait to see if system pressure rises, indicating that there is still refrigerant in liquid form or refrigerant trapped in oil incorrect options: immediately disconnect recovery equipment, break vacuum with N2, pressurize system with N2 |
| In refrigeration system, component directly following evaporator is: | correct answer: accumulator incorrect options: receiver, metering device, condenser |
| Reciprocating compressor should not be energized when: | correct answer: discharge service valve is closed incorrect options: suction service valve is open, discharge service valve is open, there is demand for cooling |
| Refrigerant pressure inside R-410A unit which is at room temperature (72 degrees F) and not operating is: | correct answer: approximately 210psig (rounded between nearest corresponding R-410A pressures of 201psig for 70 degrees F saturation temperature and 218psig for 75 degrees F) incorrect options: approximately 74psig, 110psig, 310psig |
| Every air conditioning or refrigeration system should be protected by: | correct answer: pressure relief device incorrect options: properly located stop valve, low pressure control, refrigerant receiver |
| To change compressor on system containing 40 pounds of R-500 using recycling machine that was manufactured after November 15, 1993, you must isolate compressor then: | correct answer: evacuate isolated section of system to 10 inches of vacuum and hold, if system pressure does not rise remove compressor incorrect options: atmospheric pressure, 15 inches of vacuum, simply remove compressor |
| When inspecting system for leaks, you should look for: | correct answer: traces of oil incorrect options: frost on pipes, puddles of liquid refrigerant, particles from drier core |
| When new system has been assembled, first thing to do is: | correct answer: pressurize system with inert gas and leak check incorrect options: evacuate system, pressurize system with refrigerant to be used in system, introduce initial charge of refrigerant and start compressor |
| R-410A is different from ASHRAE 400 series non-azeotropic blends because: | correct answer: R-410A behaves as near azeotropic refrigerant and can be topped off incorrect options: R-410A is HCFC, uses mineral oil, all of above |
| Manifold gauge set hoses should have self-sealing connectors or hand valves to: | correct answer: minimize release refrigerant when hoses are connected and disconnected incorrect options: minimize chance of explosion during use, prevent venting during recycling, prevent vapor lock during rapid liquid transfer |
| When using recovery or recycling equipment that was manufactured after November 15, 1993, you must evacuate system containing more than 200 pounds of CFC-12 to what level before making major repair? | correct answer: 15 inches of Hg vacuum incorrect options: 0psig, 4 inches of Hg vacuum, 10 inches of Hg vacuum |
| With air-cooled condenser on roof of building and evaporator on first floor, recovery should first occur: | correct answer: from liquid line entering evaporator incorrect options: from vapor line entering condenser, from discharge of compressor, on suction side of compressor |
| Never use oxygen or compressed air to leak check hardware because R-410A can: | correct answer: explode when mixed with air or oxygen incorrect options: fractionate when mixed with oxygen, condense when exposed to oxygen, none of above |
| Dry nitrogen should be used to break first vacuum when dehydrating by triple evacuation method. However, it: | correct answer: can be dangerous if not used with pressure regulator incorrect options: often contains moisture, is expensive, is toxic |
| Recovery machine that uses hermetic compressor will overheat when drawing deep vacuum because: | correct answer: motor needs flow of refrigerant through compressor to provide motor cooling incorrect options: it runs faster, oils used in hermetic compressors burn at lower temperatures, has higher compression ratio limit |
| Proper charging method for blended (non-azeotropic) refrigerants (400 series) is to remove charge from cylinder as: | correct answer: liquid incorrect options: vapor, superheated vapor, subcooled liquid |
| After refrigerant liquid has been recovered from system, any remaining vapor is: | correct answer: condensed by recovery system incorrect options: purged into atmosphere, isolated in system, pumped into system receiver |
| What refrigerant should you use as trace gas with nitrogen to identify leak with electronic detector? | correct answer: system refrigerant incorrect options: CFC-11, CFC-12, CFC-13 |
| Oil sample should be taken when: | correct answer: compressor has burned out incorrect options: new filter drier has been installed, unit is not cooling properly, recycled refrigerant has been added to unit |
| In refrigeration system with TXV (or other type of throttling device), component directly following condenser is: | correct answer: (liquid) receiver incorrect options: metering device, accumulator, evaporator |
| Recovered refrigerant may contain which of following? | correct answer: all of above (acids, moisture, and oils) |
| Backseating of suction shutoff valve will close: | correct answer: gauge port incorrect options: suction line and compressor port, compressor and gauge port, compressor port |
| Which repair would always be considered major under EPA regulations? | correct answer: replacement of evaporator coil incorrect options: replacement of filter drier, replacement of Schrader valve core, replacement of condenser fan motor |
| Compressor heater is used to: | correct answer: reduce amount of refrigerant in lubricating oil incorrect options: prevent refrigerant vaporization, remove entrained water, prevent acid pitting |
| Your recovery/recycling machine has R-502 refrigerant in it. You now have to recover refrigerant from unit with R-22. What must be done before R-22 refrigerant can be recovered/recycled? | correct answer: recover as much of R-502 from recovery unit as possible, change filter, and evacuate incorrect options: nothing as long as recovery machine is not full, change expansion valve on recovery machine, change filter and expansion valve |
| Fastest way to recover refrigerant from system is to remove it in what phase? | correct answer: liquid incorrect options: vapor, initial, final |
| Before using recovery unit to remove charge, what steps should be taken? | correct answer: all of above (check service valve positions, check oil level in recovery unit, evacuate recovery unit and recovery tank) |
| Deep vacuum is usually measured in: | correct answer: microns incorrect options: psig, psia, inches of Hg |
| Before transferring refrigerant to empty cylinder: | correct answer: cylinder should be evacuated to avoid mixing air with recovered refrigerant incorrect options: refrigerant should be chilled, refrigerant should be mixed, cylinder should be heated |
| To recover liquid refrigerant, you must connect one hose to: | correct answer: liquid line incorrect options: compressor suction valve, compressor discharge valve, top of condenser |
| System can be evacuated to only atmospheric pressure when: | correct answer: leaks in appliance make evacuation to prescribed level unattainable incorrect options: repair is major, repair is followed by evacuation of appliance to environment, appliance is being disposed |
| Vacuum pump used to evacuate system should be capable of pulling vacuum of: | correct answer: 500 microns incorrect options: 10mm Hg, 20mm Hg, 1,000 microns |
| While R-410A is high pressure refrigerant, it can be stored in back of service van as long as: | correct answer: temperature inside vehicle does not exceed 125 degrees F (same guidance given for all common refrigerants) incorrect options: R-22 can be stored in vehicles exceeding 125 degrees F, temperature inside vehicle does not exceed 155 degrees F |
| When under deep vacuum, motor winding of hermetic refrigeration compressor: | correct answer: will be damaged if energized incorrect options: must be kept warm to operate properly, will be protected by its insulation if compressor is energized, will overheat only if crankcase heater is energized |
| Which statement is not true about recycling and recovery equipment manufactured after November 15, 1993? | correct answer: must have oil separator incorrect options: must be tested by EPA approved third party, must meet vacuum standards more stringent than those met by equipment manufactured before November 15, 1993, must be equipped with low-loss fittings |
| When unit is opened for servicing, what should always be replaced? | correct answer: filter drier incorrect options: thermostat, metering device, crankcase heater |
| When servicing operating unit that has (liquid) receiver/storage tank: | correct answer: refrigerant should be recovered into receiver incorrect options: compressor should be isolated off, liquid should be recovered last, gauge pressure should be achieved by venting |
| Use what to remove ice from sight glass? | correct answer: alcohol spray incorrect options: water, R-11 refrigerant, screwdriver or flat file |
| Refrigerant pressure inside R-12 unit which is at room temperature (72 degrees F) and not operating is: | correct answer: approximately 74psig (rounded between nearest corresponding R-12 pressures of 70.1psig for 70 degrees F saturation temperature and 76.8psig for 75 degrees F) incorrect options: approximately 154psig, 214psig, 304psig |
| Routine maintenance task which must be performed on refrigerant recycling machines is to: | correct answer: change filter and compressor oil (if any) incorrect options: check compressor seals, change electrical fuses, replace moisture sight glass |
| Refrigerant should be removed from condenser outlet if: | correct answer: condenser is below receiver incorrect options: condenser is on roof, compressor is inoperative, evaporator has leak |
| When evacuating system, use of large vacuum pump could: | correct answer: cause trapped water to freeze incorrect options: cause trapped oil to freeze, cause trapped refrigerant to freeze, cause valves to freeze |
| On refrigeration units that use belt-driven compressor, what is most likely to leak if unit is not used for several months? | correct answer: rotating shaft seal incorrect options: suction service valve, oil drain plug, discharge service valve |
| Primary water source for cooling condenser of water-cooled recovery unit is: | correct answer: local municipal water supply incorrect options: deionized water, chilled water, condenser water |
| Evaporation temperature of R-410A at 100psig is about: | correct answer: 30 degrees F (rounded from 97psig as nearest R-410A pressure to 100psig) incorrect options: 0 degrees F, 90 degrees F, 120 degrees F |
| Non-condensables in system cause: | correct answer: higher discharge pressure incorrect options: lower suction pressure, higher suction pressure, lower discharge pressure |
| When charging R-410A system that uses water-cooled condenser, you must first charge with vapor to pressure of at least what before switching to liquid charging? | correct answer: 120psig (rounded from 118psig for saturation temperature above 36 degrees F on P/T chart for R-410A) incorrect options: 20psig, 220psig, 320psig |
| Recovery rate can be increased by: | correct answer: packing recovery vessel in ice incorrect options: heating recovery vessel, using smaller recovery vessel, using standard vacuum pump |
| Oil foaming usually occurs in: | correct answer: compressor incorrect options: condenser, evaporator, expansion device |
| During evacuation of system that contains large amounts of moisture, it may be necessary to increase pressure in system with what gas to counteract freezing of moisture? | correct answer: nitrogen incorrect options: hydrogen, oxygen, air |
| Prior to replacing condenser coil in high pressure system, refrigerant was recovered and stored in refillable cylinder. The refrigerant: | correct answer: can probably be charged back into system incorrect options: should probably be replaced with R-410A, must be reclaimed, must be destroyed |
| Evaporation temperature of R-134a at 0psig is: | correct answer: -15 degrees F (rounded from -0.1 inches Hg vacuum for R-134a pressure at -15 degrees F on P/T chart) incorrect options: -21 degrees F, -5 degrees F, -1 degree F |
| When servicing 60 ton packaged rooftop unit, easiest way to check type of refrigerant it uses is to: | correct answer: look at unit nameplate incorrect options: use service gauge set and refrigerant card, ask owner, determine condenser size |
| EPA regulations require that any appliances containing more than 50 pounds of refrigerant (except for commercial and industrial process refrigeration) must be repaired when leak rate exceeds what percentage of charge per year? | correct answer: 10% incorrect options: 5%, 20%, 30% |
| EPA regulations require that leaking commercial or industrial process refrigeration equipment must be repaired when leak rate exceeds what percentage of charge per year? | correct answer: 30% incorrect options: 5%, 10%, 20% |
| System-dependent recovery equipment cannot be used when: | correct answer: appliance contains over 15 pounds of refrigerant incorrect options: appliance is leaking, compressor of appliance is operational, ambient temperature is over 115 degrees F |
| Moisture is removed from system by: | correct answer: using filter drier incorrect options: purging condenser, draining oil separator, reducing water flow to condenser |
| Which component is not part of low side of system? | correct answer: (liquid) receiver incorrect options: evaporator, suction line, accumulator |
| Soap bubble testing is used: | correct answer: to pinpoint refrigerant leaks incorrect options: only with CFCs and HCFCs, to detect water leaks, to see if condenser or evaporator is excessively dirty |
| Refrigerant leaves receiver of system as: | correct answer: high pressure liquid incorrect options: low pressure liquid, low pressure vapor, high pressure vapor |
| Recovery of refrigerant from system as vapor only will minimize loss of: | correct answer: oil incorrect options: water, refrigerant, all of above |
| Type II leak repair requirements are same as what other type of appliance/system? | correct answer: Type III incorrect options: Type I, all types, MVAC |
| Heat pumps that use R-134a should be leak checked with: | correct answer: pressurized nitrogen incorrect options: CFCs, HCFCs, compressed dry air |
| On high pressure system, what is indicator of possible leak? | correct answer: excessive superheat incorrect options: high head pressure, low water temperature, frequent purging |
Created by:
hm2795
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