Commercial Refrigeration II Practice Exam

These questions are part of the practice quiz. Start practicing

• What type of systems normally use crankcase pressure regulators?
• The run winding on a compressor has a resistance of 0 Ω. This indicates that:
• On a starting relay, the component can be tested to see if it is electrically acceptable using a standard ________ or capacitance meter.
• Which datum would be considered baseline when comparing condenser efficiency over time?
• If the maximum continuous current rating is 20 A, what is the approximate RLA?
• Which component is typically installed in the discharge line leaving the compressor to separate oil from the refrigerant?
• Baseline condenser data includes what type of measurement?
• For new systems, when should baseline data be recorded?
• The correct way to discharge a capacitor is:
• When installing a solenoid valve, which statement is correct?
• Along with the refrigerant that is being discharged, compressors will discharge which of the following as it leaves the compressor?
• Baseline condenser data helps to establish a reference for which variable?
• A reciprocating compressor with leaking valves will operate with:
• When checking the resistance of the compressor start winding, a reading of OL on the multimeter indicates what?
• The coil of a current relay used with small single-phase compressors should have a resistance of approximately 0.1 Ω. Which of the following is closest to that value?
• Ultrasonic leak detectors locate refrigerant leaks by:
• Moisture in the refrigeration system can cause which of the following?
• What must technicians measure after a system cleanup to verify performance?
• If noncondensable gases are present in the system, which statement best describes the expected condenser pressure relative to the PT chart for the same refrigerant and temperature?
• How is a compressor's rated load amp rating, RLA, determined?
• What is a safer, non-brazing method for removing copper tubing connections when servicing equipment?
• A hot compressor with an infinite ohms reading between common and the other two terminals and a reading of 4.3 Ω between the start and run terminals most likely has:
• Which line is connected to indicators if the liquid oil acid test kit cannot be used?
• Which trio of measurements is commonly used for electrical troubleshooting?
• To check the amount of electrical current a load is drawing, technicians use a(n):
• Which of the following is an example of baseline evaporator data?
• If an ohmmeter test shows infinite resistance between the terminals of a compressor winding, this indicates:
• If an ohmmeter shows continuity but the resistance value is much lower than expected, this indicates:
• Noncondensable gases in the refrigeration system can cause which of the following other symptoms?
• The three major electrical defects in compressor motors that can be identified using an ohmmeter are:
• When should a technician record a system's baseline data?
• What does a reading of 0 Ω on the run winding indicate?
• In a system with multiple evaporators, which device helps regulate evaporator pressure across the evaporators?
• What property of POE oil used with HFC refrigerants necessitates liquid-line filter driers?
• A winding that shows continuity to the compressor housing indicates:
• With the compressor off, a technician compares the pressure of an air-cooled condenser with the pressure given on the PT chart for that refrigerant and temperature. The system pressure is considerably higher than the pressure indicated on the PT chart for that refrigerant and temperature. This indicates that:
• Which statement describes the parameters included in a baseline performance check?
• After a system cleanup, the system's performance should be verified by ________ and recording key system operating performance specifications.
• The contacts in a potential relay are typically in what state under normal operating conditions?
• Which type of valve is NOT considered an isolation valve?
• A bulging body on a run capacitor indicates which condition?
• Which component is designed to absorb moisture and contaminants from the refrigerant?
• Baseline condenser data point commonly used to assess inlet conditions is?
• Which condition is NOT considered when selecting a CPR valve?
• Many technicians use a(n) ________ to measure all electrical characteristics.
• Electrical components can generally be divided into two groups:
• Where in the system is an oil separator installed?
• The coil of a current relay used with small single-phase compressors should have a resistance of approximately:
• A TEV overfeeding condition can be caused by which of the following sensor problems?
• After a system cleanup the system should be charged:
• When replacing or repairing any electrical components, always verify that the:
• To check for electrical potential at a switch or a load, technicians use a(n).
• Which option correctly identifies the two basic types of relief valves used on refrigeration systems?
• During troubleshooting, before documenting any of the system's pressures or temperatures it is best practice to:
• When recovering contaminated refrigerant, the high-side gauge should be connected to which line?
• The inlet of the recovery pump should include?
• Which item is not typically included in a baseline performance check?
• The coil of a potential relay used with small single-phase compressors should have a resistance of approximately:
• What is the material inside the filter drier called?
• An example of baseline condenser data is which temperature value?
• To check the condition of the compressor's motor windings, a technician will need to measure the resistance of the windings using:
• Moisture in the refrigeration system can also cause which of the following?
• Why is nitrogen used to purge the system before using the flushing solvent?
• During normal defrost, the compressor is:
• What visual clue on a system can indicate the presence of a refrigerant leak?
• To isolate a semihermetic compressor from system pressure:
• Electrical components can be categorized into two groups:
• When cleaning up after a compressor burnout, immediately after you recover the refrigerant, you should
• After a capacitor is discharged:
• Noncondensable gases in the refrigeration system can cause which of the following?
• What happens if you remove tubing before all the brazing material is molten?
• On run capacitors, any sign of bulging of its body is a sign of a(n) ________ capacitor.
• Which statement about a system's baseline data is true?
• When flushing the system, you should:
• When checking the resistance of the compressor start winding, a multimeter shows 3.1 Ω. This indicates:
• Which refrigeration device would most likely be installed in the discharge line leaving the compressor to prevent liquid refrigerant from draining from a raised condenser into the compressor head?
• What are the most common desiccant materials used in driers?
• RLA stands for which term in refrigeration systems?
• Which parameter is an example of baseline condenser data?
• What is the main advantage of a pressure relief valve on a receiver compared to a fusible plug?
• If a filter drier becomes clogged, what symptom would you expect?
• Using heat-reclaim coils will help improve a building's overall:
• What does a crankcase pressure regulator do?
• What does an evaporator pressure regulator primarily do?
• Which statement best describes the flow characteristic of ball valves in refrigeration systems?
• Overdefrosting is caused by:
• You should flush the system:
• Before opening the compressor crankcase to take an oil sample, you should
• Which device is designed to separate and collect some of the oil in the discharge line and return it to the compressor's crankcase?
• The advantage of ball valves over other types of manual refrigeration valves is that they:
• Oil separators return oil to which location in the compressor system?
• Why should technicians be cautious when taking an oil sample from a semihermetic compressor?
• A safer alternative to debrazing components is to:
• If a restriction clears up when the system is turned off and allowed to warm, the restriction was probably due to:
• How can a technician determine when a filter drier is stopped up and needs changing?
• Why should the temperature inside the compressor be kept under 300°F?
• During a system cleanup, changing the oil in a hermetic compressor:
• A commonly observed sign that the filter drier is blocked is
• What are the three main circuit characteristics commonly measured to troubleshoot electrical circuits?
• After reassembling the system
• To manually defrost a frozen evaporator coil, technicians should:
• An iced-up evaporator in a commercial freezer can be caused by which of the following?
• With three-phase compressors, a voltage imbalance of greater than ________ will cause the windings within a motor to generate heat beyond safe levels, leading to premature motor failure.
• Why are liquid-line filter driers required for all systems using HFC refrigerant?
• Why is it necessary to have controls for maintaining a minimum high-side pressure on outdoor air-cooled condensers?
• Which of the following is another effect of small carbon particles inside the refrigeration system?
• When reviewing condenser performance, baseline data should include which measurement?
• After a compressor burnout cleanup, what is the key oil maintenance step?
• Which of the following is an example of baseline condenser data used in energy efficiency assessments?
• In most commercial refrigeration systems, where is the excess refrigerant that is not being used stored?
• What is a common cause of overdefrost in a defrost cycle other than a refrigerant issue?
• How can you tell when a filter drier is stopped up?
• The current relay coil is wired in which location in the circuit?
• If a compressor start winding resistance test shows OL, which conclusion is most accurate?
• If a technician needs to check the refrigerant pressures on a system with a small charge:
• Suction line filters are generally designed
• Why is the filter drier important?
• After diagnosing a defective compressor, the technician should:
• Baseline condenser data typically includes which measurement?
• Just before charging the system with clean refrigerant, you should
• Which statement correctly describes common desiccants used in driers?
• Which of the following is a possible cause of underfeeding the TEV?
• Moisture indicators are normally part of which component?
• If the compressor oil on a hermetic compressor is acidic, the next step is to change the:
• In a baseline condenser data log, which value is recorded?
• Which gas is used to purge the flush after flushing lines and coils?
• Which parameter is used as a baseline data point for condensers?
• When debrazing a joint on a refrigeration system, often
• How do evaporators in medium-temperature refrigeration cases normally defrost?
• A suction superheat measurement higher than the manufacturers’ recommended setting indicates which condition?
• When troubleshooting single-phase compressor motors, it is important that the technician:
• If you try to remove tubing before all the brazing material is molten, the tubing will:
• Which of the following is an effect of small carbon particles inside the refrigeration system?
• Voltage drop across a switch indicates that:
• Which component’s failure is listed as a possible cause of an iced-up evaporator in the given material?
• What is the difference between a standard liquid line drier and a filter designed to be used following a flush procedure?
• If the liquid oil acid test kit cannot be used, indicators may be connected to the
• A discharge-line check valve primarily prevents which condition?
• Which condition is most consistent with an acidic oil found in a hermetic compressor, requiring action?
• A crankcase pressure regulator is designed to prevent compressor suction pressure from rising above what value?
• One method of elevating system liquid pressure is to
• Which procedure should be followed to safely isolate a semihermetic compressor from system pressure?
• What is the advantage of using a pressure relief valve to protect a receiver instead of a fusible plug?
• A healthy start winding test result would show:
• Which systems use evaporator pressure regulators (EPR)?
• The contacts of a current starting relay are:
• A flow control device that stops or allows the flow of a refrigerant in a refrigeration system based on an electric signal is called a
• What is the proper method for charging a system after cleanup according to the discussed guidelines?
• A suction-to-liquid line heat exchanger typically:
• Which of the following is an example of baseline condenser data?
• One basic rule a technician must follow while searching for a leak is to:
• Which valve type is typically used for on/off control but is not considered an isolation valve?
• Which combination of system parameters is typically observed when noncondensable gases are present in the refrigerant circuit?
• The starting relay contacts are described as normally open. What does this mean when the coil is not energized?
• During startup data collection for a condenser, which value is considered baseline?
• How does an oil acid test kit indicate the presence of acid?
• What are the two basic types of relief valves used on refrigeration systems?
• To increase the operating superheat on a thermostatic expansion valve:
• After a system cleanup, which evaporator value should be measured?
• When troubleshooting, small-capacity refrigeration systems:
• Turning the thermostatic expansion valve adjusting stem clockwise would have which effect on operating superheat?
• During recovery, where should the low-side gauge be connected?
• What breaks down to form poisonous gas in the presence of flames?
• Which refrigerant component prevents liquid refrigerant from returning to the compressor?
• Which of the following is a potential cause of overfeeding the TEV?
• What gas is used for leak testing after reassembly of the system?
• What is meant by a system's baseline data?
• Baseline condenser data focuses on inlet condition measured as?
• In a performance log, baseline condenser data is typically recorded as?
• If suction superheat is lower than recommended, the most likely reason is:
• After flushing the lines and coils, the flush should be purged out using which gas?
• Which instrument provides a visual indication of moisture condition in a refrigerant system?
• How does accumulated dirt on the condenser coil affect system operation?
• What is the default state of the contacts in a potential relay?
• The potential relay coil is wired:
• What effect do noncondensable gases have on system performance?
• Noncondensable gases can contribute to which performance issue?
• During troubleshooting, if the superheat value of the refrigerant leaving an evaporator is higher than normal:
• A suction superheat measurement lower than the manufacturer's recommended superheat setting indicates that:
• The capacitor testing function on many multimeters will NOT read correctly if: