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CSN AC 110 Esco Exam Practice Questions &
100% Verified Answers | Latest Update | Already
Graded A+
- Heat which causes a change in temperature of a substance is called; A. latent heat B. sensible heat C. superheat D. radiant heat ๐ธ๐ธ๐ธ : B. sensible heat
- Heat added to a substance without a raise in temperature; (example: liquid refrigerant to gas) this process is called? A. latent heat of vaporization B. latent heat of fusion. C. superheat of vaporization D. superheat of fusion ๐ธ๐ธ๐ธ : A. latent heat of vaporization
- Heat added to the refrigerant in a vapor state after the evaporation process is called; A. latent heat B. subcooling
C. superheat D. specific heat ๐ธ๐ธ๐ธ : C. superheat
- A scroll compressor move refrigerant by means of; A. a piston B. an impeller C. vane and cam D. involute spirals ๐ธ๐ธ๐ธ : D. involute spirals
- The movement of heat by way of fluid (or air) is called; A. conduction B. convection C. radiation D. percussion ๐ธ๐ธ๐ธ : B. convection
- The movement of heat through a solid object is called; A. conduction B. convection C. radiation D. compression
- The state of the refrigerant in the suction line should be; A. high pressure / high temperature liquid B high pressure / low temperature vapor C. low pressure / low temperature liquid D. low pressure / low temperature vapor ๐ธ๐ธ๐ธ : D. low pressure / low temperature vapor
- The state of the refrigerant entering the condenser is; A. high temperature / highly superheated liquid B. high pressure / highly superheated vapor C. high pressure / high temperature liquid D. low pressure / low temperature vapor ๐ธ๐ธ๐ธ : B. high pressure / highly superheated vapor
- the evaporator; A. transfers heat from the refrigerated space to the refrigerant B. transfers heat from the refrigerant to the refrigerated space C. transfers heat from the refrigerant to the ambient air D. transfers heat from the ambient air to the refrigerated space ๐ธ๐ธ๐ธ : A. transfers heat from the refrigerated space to the refrigerant
- Which of the following is not a thermodynamic property of refrigerants?
A. critical point B. saturation point C. enthalpy D. flammability ๐ธ๐ธ๐ธ : D. flammability
- The sequential order of steps in the vapor - compression process are; A. expansion, condensation, compression, vaporization B. vaporization, expansion, condensation, compression C. compression, condensation, expansion, vaporization D. expression, compression, vaporization, condensation ๐ธ๐ธ๐ธ : C. compression, condensation, expansion, vaporization
- If a 30 pound cylinder of reclaimed R-410A refrigerant has been stored over night at 70ยฐF, the pressure of the cylinder shoudl be approximately: A. 201 psig B. 168 psig C. 143 psig D. 118 psig ๐ธ๐ธ๐ธ : A. 201 psig
- Fan airflow pressures are usually measured in; A. inches of mercury vacuum or micorns
D. condensate point ๐ธ๐ธ๐ธ : C. dew point temperature
- A compound pressure gauge measures; A. pressure and vacuum B. pressure and temperature C. pressure and humidity D. wet and dry bulb temperatures ๐ธ๐ธ๐ธ : A. pressure and vacuum
- A mechanical shaft seal is necessary on a; A. semi-hermetic compressor B. hermetic reciprocating compressor C. hermetic rotary compressor D. open drive compressor ๐ธ๐ธ๐ธ : C. hermetic rotary compressor
- Liquid slugging is; A. a pounding noise caused by liquid refrigerant in the suction line at the point of restriction B. noise caused by excessive liquid refrigerant in the condenser C. liquid refrigerant in the compressor clearance space D. excessive liquid refrigerant in the receiver
๐ธ๐ธ๐ธ : C. liquid refrigerant in the compressor clearance space
- The clearance of space in a reciprocating compressor; A has no effect on compressor capacity B. has an effect on compressor capacity C. varies depending on compressor speed D. is the same on all compressors ๐ธ๐ธ๐ธ : B. has an effect on compressor capacity
- Which of the following types of air conditioning compressors is most energy efficient? A. Reciprocating B. Centrigugal C. Rotary vane D. Scroll ๐ธ๐ธ๐ธ : D scroll
- Which of the following represent the right order for functions of a condenser? A. sub-cools, condenses, de-superheats B. de-superheats, condenses, sub-cools C. condenses, sub-cools, de-superheats D. sub-cools, de-superheats, condenses ๐ธ๐ธ๐ธ : B. de-superheats, condenses, sub-cools
D. 110ยฐF
๐ธ๐ธ๐ธ : C. 100ยฐF
- The heat removed from the refrigerant by the condenser is; A. sensible heat only B. latent heat only C. both sensible and latent heat D. neither sensible or latent heat ๐ธ๐ธ๐ธ : C. both sensible and latent heat
- An Energy Recovery ventilator is; A. a low ambient air temperature control B. to recover the warm air from the condenser C. a high efficient attic ventilator system D. an air to air heat-exchanger to recover heat ๐ธ๐ธ๐ธ : D. an air to air heat-exchanger to recover heat
- When testing the efficiency of an air cooled condenser, the refrigerant condensing temperature should be approximately _____ higher than the entering air temperature? A. 30ยฐF B. 40ยฐF C. 100ยฐF D. 120ยฐF
๐ธ๐ธ๐ธ : A. 30ยฐF
- When testing the efficiency of a water cooled condenser, the refrigerant condensing temperature should be approximately A. 10ยฐF B. 30ยฐF C. 40ยฐF D. 50ยฐF ๐ธ๐ธ๐ธ : A. 10ยฐF
- The first function a condenser must perform is to _______ the refrigerant before condensing can occur. A. superheat B. de-superheat C. compress D. sub-cool ๐ธ๐ธ๐ธ : B. de-superheat
- A thermostatic expansion valve is designed to maintain; A. constant evaporator temperature B. constant refrigerant flow C. constant evaporator superheat D. constant evaporator pressure
- In an air conditioning system that uses a thermostatic expansion valve, the temperature of the evaporator outlet will usually be; A. cooler than the evaporator inlet B. warmer than the evaporator inlet C. the same as the evaporator inlet D. unchanged by superheat ๐ธ๐ธ๐ธ : B. warmer than the evaporator inlet
- An automatic expansion valve is best suited; A. when the system load remains fairly constant B. when the system load varies greatly C. when the compressor must start often D. when multiple evaporators are used ๐ธ๐ธ๐ธ : A. when the system load remains fairly constant
- Which of the following is not true of a capillary tube metering device? A. they have no moving parts B. they allow pressures to equalize after the compressor shuts down C. they maintain a constant evaporator temperature D. they are sized to match system capacity ๐ธ๐ธ๐ธ : C. they maintain a constant evaporator temperature
- A decrease in superheat causes The thermostatic expansion valve to begin to; A. open B. close C. flood the evaporator D. starve the evaporator ๐ธ๐ธ๐ธ : B. close
- a rise in evaporator pressure causes the automatic expansion valve to begin to; A. open B. close C. flood the evaporator D. starve the evaporator ๐ธ๐ธ๐ธ : A. open A thermal-electric (solid state) expansion valve is controlled by; A. suction pressure B. NTC thermistor C. thermal bulb D. external equalizing port ๐ธ๐ธ๐ธ : B. NTC thermistor
- In a direct expansion (DX) evaporator system, the refrigerant enters the evaporator as;
B. compressor and the condenser C. condenser and the metering device D. metering device and ht evaporator ๐ธ๐ธ๐ธ : C. condenser and the metering device
- the only way to minimize flash gas is by; A. increase the superheating setting on the thermostatic expansion valve to correspond with the compressor horsepower B. change the evaporator fan to a lower setting C. sub-cooling the liquid refrigerant entering the metering device closer to the evaporator temperature D. change the evaporator fan speed to a higher setting ๐ธ๐ธ๐ธ : C. sub-cooling the liquid refrigerant entering the metering device closer to the evaporator temperature
- A liquid receiver is used to; A prevent liquid refrigerant from reaching the compressor B. separate oil from the liquid refrigerant C. store liquid refrigerant D. receive and store vapor refrigerant ๐ธ๐ธ๐ธ : C. store liquid refrigerant
- An accumulator is used to;
A. prevent liquid refrigerant from reaching the compressor B. separate oil from the liquid refrigerant C. store liquid refrigerant D. receive and store vapor refrigerant ๐ธ๐ธ๐ธ : A. prevent liquid refrigerant from reaching the compressor A sight glass would normally be located A. in the liquid line, before the metering device B. in the liquid line, after the metering device C in the suction line, before the compressor D. in the suction line, after the compressor ๐ธ๐ธ๐ธ : A. in the liquid line, before the metering device
- Bubbles in a sight glass could be an indication of; A. an overcharge of refrigerant B. low compressor capacity C. TXV with an excessive superheat setting D. a refrigerant blend with a high temperature glide ๐ธ๐ธ๐ธ : D. a refrigerant blend with a high temperature glide
- The oil separator is installed in the A. Suction line B liquid line
๐ธ๐ธ๐ธ : B increase liquid subcooling
- The oil pressure safety switch is operated by. A the sum of suction pressure and oil pressure B the sum of oil, pressure and crank case pressure C the difference between crank case, pressure and oil pressure D the difference between head pressure and oil pressure ๐ธ๐ธ๐ธ : C the difference between crank case, pressure and oil pressure
- A low pressure cut off switch is used to. A establish a minimum operating pressure in the evaporator B prevent condensing pressure from reaching dangerously high levels C sense, oil pressure in the lower portion of the compressor D prevent lo oil pressure in the crank case ๐ธ๐ธ๐ธ : A establish a minimum operating pressure in the evaporator 59.A partially iced over evaporator can be caused by. A an overcharge Be excessive airflow C. and under charge D high indoor humidity ๐ธ๐ธ๐ธ : C. an under charge
60 This can be used for leak detection with all high pressure refrigerants A soap bubbles B halide torch C open flame D electronic halogen detector ๐ธ๐ธ๐ธ : A soap bubbles
- The flow rate of a TXV used in our 410 a systems as compared to R22 systems is A equal B approximately 40% to 70% higher C approximately 15% greater D approximately 15% less ๐ธ๐ธ๐ธ : D approximately 15% less
- When using an electronic leak detector, the sensor probe. A must be moved around suspected area as fast as possible B must be exposed to a large amount of refrigerant for calibration C. should be moved at approximately 1 inch every two seconds D is not affected by dirt or oil ๐ธ๐ธ๐ธ : C. should be moved at approximately 1 inch every two seconds
- Moisture in a refrigeration system will cars. A low head pressure
