Maintenance And Troubleshooting Trivia Quiz!

Reviewed by Editorial Team
The ProProfs editorial team is comprised of experienced subject matter experts. They've collectively created over 10,000 quizzes and lessons, serving over 100 million users. Our team includes in-house content moderators and subject matter experts, as well as a global network of rigorously trained contributors. All adhere to our comprehensive editorial guidelines, ensuring the delivery of high-quality content.
Learn about Our Editorial Process
| By Enorab
E
Enorab
Community Contributor
Quizzes Created: 6 | Total Attempts: 3,543
| Attempts: 241 | Questions: 64
Please wait...
Question 1 / 64
0 %
0/100
Score 0/100
1. After you have disabled a motor disconnect, you lock and tag the panel. After this, you should be sure to keep the only key

Explanation

After locking and tagging the panel, it is important to keep the only key on your person. This means that you should have the key with you at all times, rather than leaving it at the shop, with your crew leader, or with your shop supervisor. Keeping the key on your person ensures that you have control over who can access the panel and prevents unauthorized individuals from tampering with the motor disconnect.

Submit
Please wait...
About This Quiz
Maintenance And Troubleshooting Trivia Quiz! - Quiz

Dive into the Maintenance and troubleshooting Trivia Quiz! Assess your skills in HVAC system maintenance, focusing on electrical components, thermostat operations, and cooling systems. Perfect for learners aiming to enhance practical troubleshooting abilities in HVAC systems.

Personalize your quiz and earn a certificate with your name on it!
2. A short circuit will occur in the windings of a motor when the conductors in the windings

Explanation

When the conductors in the windings of a motor touch each other, it creates a path of low resistance for the current to flow through. This results in a short circuit, where the current bypasses the intended circuit and flows directly between the touching conductors. This can cause excessive current flow, overheating, and potentially damage the motor or other components in the circuit.

Submit
3. You should never use hand tools in a

Explanation

Using hand tools in a hot electrical panel can be dangerous because the heat can cause the tools to become hot, increasing the risk of burns or injury. Additionally, the heat can affect the insulation of the wires, increasing the risk of electrical shock. It is important to wait for the panel to cool down before attempting any work to ensure safety.

Submit
4. Which fan circuit contacts must be closed to pass power to the fan motor?

Explanation

The fan relay is responsible for controlling the power supply to the fan motor. In order for power to be passed to the fan motor, the contacts of the fan relay must be closed. This allows the electrical current to flow from the power source to the fan motor, enabling it to operate.

Submit
5. What type of electrical problems will a hermetic compressor have?

Explanation

A hermetic compressor can experience all types of electrical problems, including open circuit, short circuit, and grounded circuit. An open circuit occurs when there is a break in the electrical connection, causing the compressor to not receive power. A short circuit happens when there is an unintended connection between two points, causing excessive current flow and potentially damaging the compressor. A grounded circuit occurs when an electrical conductor comes in contact with a ground, leading to potential safety hazards and malfunction of the compressor. Therefore, all of the mentioned options can be electrical problems for a hermetic compressor.

Submit
6. Most assemblies are held on the motor shaft by

Explanation

Setscrews are commonly used to hold assemblies on a motor shaft because they provide a secure and adjustable connection. Setscrews have a threaded hole that allows them to be tightened against the shaft, creating friction and preventing the assembly from slipping or rotating. This method is widely used in various applications because setscrews are easy to install and remove, making them a convenient choice for securing assemblies on motor shafts.

Submit
7. You are preparing to troubleshoot a system for an electrical problem. Before you start to troubleshoot the components, you would verify that the

Explanation

Before troubleshooting the components for an electrical problem, it is important to verify that the power supply is energized and the voltage is correct. This step ensures that the system has the necessary power to function properly and that the voltage levels are within the acceptable range. By confirming the power supply is energized and the voltage is correct, any potential issues related to insufficient power or incorrect voltage can be ruled out before proceeding with further troubleshooting steps.

Submit
8. When does the outdoor unit on a heat pump act as an evaporator?

Explanation

In winter, the outdoor unit of a heat pump acts as an evaporator. This is because during the colder months, the outdoor temperature is lower than the indoor temperature. The heat pump extracts heat from the outdoor air and transfers it inside, providing warmth to the indoor space. The outdoor unit acts as an evaporator in this process by evaporating the refrigerant, absorbing heat from the outdoor air, and then sending it to the indoor unit for further distribution.

Submit
9. What is used to supplement the unit when the outdoor temperature drops to a point where the heat pump becomes inefficient?

Explanation

Auxiliary heat is used to supplement the unit when the outdoor temperature drops to a point where the heat pump becomes inefficient. This additional heat source helps to maintain a comfortable indoor temperature by providing extra warmth when the heat pump alone is not sufficient. It can be in the form of auxiliary refrigerant or auxiliary forced air, or both, depending on the specific system.

Submit
10. What type of switch is used to prove there is water flow in both the chilled-water and condenser water circuits?

Explanation

Flow switches are used to prove that there is water flow in both the chilled-water and condenser water circuits. These switches are designed to detect the movement of water and can be installed in the pipelines. When water flows through the circuit, the flow switch is activated, indicating that there is indeed water flow. This helps in ensuring that the water is circulating properly in the system and can be used as a safety measure to prevent damage or malfunction in the equipment.

Submit
11. You turn the indoor fan switch on a thermostat to the FAN ON position. When you do, the indoor fan motor does not come on. A possible cause of the problem is that there is

Explanation

If the indoor fan motor does not come on when the indoor fan switch is turned on, a possible cause of the problem is that there is no control voltage. This means that the thermostat is not sending the necessary electrical signal to activate the fan motor. It could be due to a faulty thermostat, a wiring issue, or a problem with the power supply.

Submit
12. When a partial restriction occurs in the liquid line, the point of the restriction will act like

Explanation

When a partial restriction occurs in the liquid line, the point of the restriction will act like an expansion device. This is because an expansion device is responsible for reducing the pressure of the refrigerant and controlling its flow into the evaporator. In the case of a partial restriction, the restricted point in the liquid line will cause a drop in pressure, similar to what an expansion device does. This drop in pressure allows the refrigerant to expand and evaporate, facilitating the cooling process.

Submit
13. If the motor drive pulley and the driven pulley are out of line, strain will be imposed on the

Explanation

If the motor drive pulley and the driven pulley are out of line, strain will be imposed on the shafts' drive mechanism. When the pulleys are misaligned, it causes the shafts to be misaligned as well. This misalignment puts stress on the drive mechanism of the shafts, which can lead to increased wear and tear, decreased efficiency, and potential damage to the system. It is important to ensure proper alignment of the pulleys to prevent strain on the shafts' drive mechanism.

Submit
14. To check for a short circuit from a motor winding to ground, you would use

Explanation

To check for a short circuit from a motor winding to ground, an ohmmeter would be used. An ohmmeter is specifically designed to measure resistance and can determine if there is a low resistance path between the motor winding and ground. By connecting the ohmmeter to the motor winding and measuring the resistance, any unexpected low resistance readings would indicate a short circuit. This helps in identifying and diagnosing potential issues in the motor's electrical system.

Submit
15. Before you start the compressor on a centrifugal chiller, you must verify there is oil pressure.  To do this, you would start the oil

Explanation

Before starting the compressor on a centrifugal chiller, it is necessary to ensure that there is oil pressure. To do this, the oil pump needs to be started in manual mode. This allows the operator to manually control the oil pump and verify that there is sufficient oil pressure before starting the compressor. Starting the oil pump in auto mode would not provide the same level of control and verification. Similarly, the sump refers to the oil reservoir, and starting it in either manual or auto mode would not directly verify the oil pressure.

Submit
16. Which terminals would you use to determine why a thermostat does not pass power to the relays when a split-system air-conditioner unit is in the cooling mode?

Explanation

To determine why a thermostat does not pass power to the relays when a split-system air-conditioner unit is in the cooling mode, you would use the R, G, and Y terminals. The R terminal is used for power, the G terminal is used for the fan, and the Y terminal is used for the compressor. By checking these terminals, you can troubleshoot and identify any issues with power supply, fan operation, or compressor activation, which could be causing the thermostat to not pass power to the relays.

Submit
17. You have removed and recovered the refrigerant from a system and solder repaired a leak. Before you recharge the unit, you must first perform

Explanation

Before recharging the unit with refrigerant after repairing a leak, it is necessary to perform a leak check. This is done to ensure that there are no remaining leaks in the system that could cause the refrigerant to escape again. By conducting a leak check, any potential leaks can be identified and repaired before recharging the unit, ensuring that the system will function properly and efficiently.

Submit
18. When an exact replacement compressor for a refrigerator cannot be obtained, you would gather all data from the

Explanation

When an exact replacement compressor for a refrigerator cannot be obtained, the best course of action is to gather all data from the compressor nameplate and draw a diagram of the compressor lines and mounting. This is because the compressor nameplate contains important information such as the model number, voltage, and refrigerant type, which are necessary for finding a suitable replacement. Additionally, drawing a diagram of the compressor lines and mounting will help ensure that the replacement compressor is installed correctly and fits properly in the refrigerator.

Submit
19. A run capacitor on an eletric motor is constructed as a

Explanation

The run capacitor on an electric motor is constructed as a metal can because metal cans provide better durability and protection for the internal components of the capacitor. Metal cans are able to withstand high temperatures and provide better insulation, ensuring the capacitor's longevity and efficient operation. Additionally, metal cans are less prone to damage from external factors such as moisture or physical impact, making them a reliable choice for this application.

Submit
20. A motor that has a bad run capacitor

Explanation

A motor that has a bad run capacitor may run at a lower-than-normal speed because the run capacitor is responsible for providing an extra boost of power to the motor during start-up. Without a functioning run capacitor, the motor may struggle to start and may not be able to reach its normal operating speed. As a result, the motor may run at a lower speed than usual.

Submit
21. The three components that operate in the cooling mode are the

Explanation

The correct answer is indoor fan, the compressor, and the outdoor fan. In the cooling mode, the indoor fan helps circulate the cool air throughout the room, while the compressor is responsible for compressing and cooling the refrigerant. The outdoor fan helps dissipate the heat from the refrigerant to the outside environment, completing the cooling cycle.

Submit
22. Mechanical motor problems normally occur at the

Explanation

Mechanical motor problems typically arise at the bearings or the shaft. Bearings are essential components of a motor as they support the rotating shaft, allowing it to spin smoothly. Over time, bearings can wear out or become damaged, leading to issues such as excessive noise, vibration, or even complete motor failure. Similarly, problems with the shaft, such as misalignment or excessive play, can cause the motor to malfunction. Therefore, it is crucial to regularly inspect and maintain the bearings and shaft to prevent and address any potential motor problems.

Submit
23. You make a continuity check on a compressor. The check indicates that the common circuit in the compressor is open. You feel the compressor dome and it is very hot. In this situation, you would suspect that the

Explanation

In this situation, if the common circuit in the compressor is open and the compressor dome is very hot, it suggests that the internal overload protector is open. The internal overload protector is a safety device designed to protect the compressor from overheating. When it senses excessive heat, it opens the circuit to prevent further damage. The fact that the compressor dome is hot indicates that the compressor has been running and generating heat, which further supports the suspicion that the internal overload protector is open.

Submit
24. The motor problems that can occur inside a hermetic compressor are

Explanation

The correct answer is "an open circuit, short circuit, and grounded circuit". This answer accurately identifies the motor problems that can occur inside a hermetic compressor. An open circuit refers to a break in the electrical connection, causing a lack of current flow. A short circuit occurs when there is an unintended connection between two points in the circuit, resulting in excessive current flow. A grounded circuit refers to a connection between the circuit and the ground, which can cause electrical faults and damage to the motor.

Submit
25.  What is the possible cause when a motor will not start, hums and trips on overload?

Explanation

If a motor will not start, hums, and trips on overload, the possible cause could be an incorrect power supply. This means that the motor is not receiving the correct voltage or current required for it to start and operate properly. This could be due to issues with the wiring, a faulty power source, or incorrect connections. It is important to ensure that the motor is receiving the correct power supply in order to prevent damage and ensure proper functioning.

Submit
26. What should be done to water chillers during the winter?

Explanation

During the winter, water chillers should be completely drained. This is because if the chiller is filled with water, it can freeze and cause damage to the system. By draining the chiller, there is no water left that can freeze and expand, potentially leading to cracks or other issues. Therefore, draining the chiller is the best course of action to prevent any damage during the winter season.

Submit
27. A start capacitor on an eletric motor is constructed as a

Explanation

The start capacitor on an electric motor is constructed as a dry type. This means that it does not contain any liquid or oil inside. Dry type capacitors are commonly used in motors because they are more reliable and have a longer lifespan compared to wet type capacitors. They are also less prone to leakage and corrosion. Additionally, dry type capacitors are more compact and can be easily installed in various motor designs. Therefore, using a dry type start capacitor ensures the efficient and safe operation of the electric motor.

Submit
28. Which is designed to stop the defrost cycle of a low-temperature walk-in?

Explanation

A termination switch is designed to stop the defrost cycle of a low-temperature walk-in. This switch is responsible for sensing when the defrost cycle has reached its desired temperature and then terminating the cycle. It ensures that the walk-in does not continue to defrost for longer than necessary, preventing excessive energy consumption and potential damage to the walk-in. The other options, such as low-pressure motor control, high-pressure safety switch, and oil pressure switch, are not specifically designed for this purpose.

Submit
29. The temperature range of a refrigeration system depends upon the

Explanation

The temperature range of a refrigeration system depends on the product being refrigerated. Different products have different temperature requirements for storage or preservation. For example, certain perishable foods may require lower temperatures to prevent spoilage, while other products like beverages may only need a slightly cooler temperature. Therefore, the specific product being refrigerated determines the temperature range needed in the system.

Submit
30. The most probable causes of an inefficient evaporator are

Explanation

An inefficient evaporator can be caused by a dirty coil and a fan running too slow. A dirty coil reduces the heat transfer efficiency, making the evaporator less effective in cooling the air. Additionally, a fan running too slow can result in insufficient airflow across the coil, further reducing the cooling capacity. Both of these factors contribute to the inefficiency of the evaporator.

Submit
31. After you have cleaned the tubes in a condenser, how would you check their condition for defects?

Explanation

To check the condition of the tubes in a condenser for defects, an eddy-current check is conducted. This non-destructive testing method involves passing an alternating current through the tubes, which generates eddy currents. These currents interact with any defects or abnormalities in the tubes, causing a change in the electrical impedance. By measuring this change, any defects such as cracks, corrosion, or thinning of the tube walls can be detected. This method is effective in identifying hidden defects and providing a comprehensive assessment of the tube's condition.

Submit
32. Which is an indication that the defrost system is not operating properly?

Explanation

When the defrost system is not operating properly, the manually initiated defrost is terminated by the temperature sensing device. This means that even if the defrost is manually started, it will not continue until the temperature sensing device detects that the appropriate temperature has been reached. This indicates that the defrost system is not functioning correctly and may need to be repaired or replaced.

Submit
33. To safely check an electrical component for continuity or resistance, you would turn

Explanation

To safely check an electrical component for continuity or resistance, it is important to turn off the power and disconnect at least one lead from the component. This is because working with live electrical circuits can be dangerous and may result in electric shock or damage to the meter or the component. By turning off the power and disconnecting at least one lead, you ensure that there is no electrical current flowing through the circuit, making it safe to perform the continuity or resistance test.

Submit
34. Most manufacturers illustrate the wiring in their equipment through the use of

Explanation

Manufacturers typically use pictorial and line diagrams to illustrate the wiring in their equipment. Pictorial diagrams provide a visual representation of the components and their connections, making it easier for technicians to understand the wiring layout. On the other hand, line diagrams use standardized symbols to represent the electrical components and their interconnections. By combining these two types of diagrams, manufacturers can provide a comprehensive and clear representation of the equipment's wiring, ensuring efficient installation and troubleshooting processes.

Submit
35. To verify that the refrigerant is boiling at the correct temperature for the low side of the system at a given load condition, you would use

Explanation

To verify that the refrigerant is boiling at the correct temperature for the low side of the system at a given load condition, you would use the low-side gauge readings. This is because the low-side gauge provides information about the pressure and temperature of the refrigerant as it enters the evaporator coil. By monitoring the low-side gauge readings, you can ensure that the refrigerant is boiling at the correct temperature, which is crucial for efficient cooling and proper functioning of the system. The high-side gauge readings and ultralow pressure gauge readings may provide additional information, but they are not specifically used to verify the boiling temperature of the refrigerant on the low side.

Submit
36. Calculate the discharge pressure for an R–502 system operating at 95*F outside ambient temperature.  

Explanation

not-available-via-ai

Submit
37. An oil sample from the crankcase of a centrifugal compressor should be sent to an oil laboratory on

Explanation

The oil sample from the crankcase of a centrifugal compressor should be sent to an oil laboratory on an annual basis. This is because the oil in the crankcase of a centrifugal compressor typically lasts for a longer period of time before needing to be replaced or analyzed. Sending the sample on an annual basis allows for regular monitoring of the oil's condition and helps to ensure that it is still performing effectively and not causing any issues with the compressor's operation.

Submit
38. You use your volt-ohm-milliammeter to check a transformer. You find it has an open. In this situation, the probable trouble is

Explanation

In this situation, the probable trouble is a burned transformer. This means that the transformer has suffered damage, possibly due to overheating or a fault in the electrical circuit. As a result, the transformer is no longer functioning properly and may need to be replaced.

Submit
39. You can reduce the danger involved in attaching high-pressure gauges on a manifold by stuttin off the

Explanation

not-available-via-ai

Submit
40. A single-phase condition in a three-phase motor can be caused by

Explanation

A blown fuse can cause a single-phase condition in a three-phase motor because it disrupts the flow of electrical current to one or two phases, resulting in the motor only operating on a single phase. This can happen if the fuse is overloaded or if there is a short circuit in the motor's electrical system. When a fuse blows, it breaks the circuit and prevents the motor from receiving power from the affected phase(s), causing it to operate at reduced capacity or not at all.

Submit
41. What is the normal maximum reduction of temperature in a cooling tower water if the ambient wet-bulb temperature is 85*F?

Explanation

In a cooling tower, the maximum reduction of temperature is determined by the difference between the ambient wet-bulb temperature and the temperature of the water leaving the tower. The wet-bulb temperature represents the lowest temperature that can be achieved through evaporation. Therefore, if the ambient wet-bulb temperature is 85°F, the normal maximum reduction of temperature in the cooling tower water would be 78°F, as this represents the maximum potential for evaporation and cooling.

Submit
42. On a trouble call, you determine that voltage is present from R to Y at the thermostat but no voltage is present at the condenser contactor. In this situation, you would suspect that the

Explanation

In this situation, if voltage is present from R to Y at the thermostat but no voltage is present at the condenser contactor, it suggests that the Y wire is broken. The Y wire is responsible for transmitting the signal from the thermostat to the condenser contactor, so if it is broken, the voltage will not reach the contactor. This would explain why there is voltage at the thermostat but not at the contactor.

Submit
43. The function of the indoor coil on a heat pump unit is to

Explanation

The indoor coil on a heat pump unit serves as an evaporator in the summer, absorbing heat from the indoor air and transferring it to the outdoor unit to be released. In the winter, it functions as a condenser, absorbing heat from the outdoor air and transferring it to the indoor air to provide heating. This allows the heat pump to provide both cooling and heating capabilities throughout the year.

Submit
44. A refrigerator may have condensation (sweat) on the outside of the cabinet if the

Explanation

If a refrigerator has condensation (sweat) on the outside of the cabinet, it indicates that the mullion heater is defective. The mullion heater is responsible for preventing condensation by maintaining the exterior surface of the refrigerator at a temperature above the dew point. If the mullion heater is not functioning properly, it fails to keep the surface warm, resulting in condensation forming on the outside of the cabinet.

Submit
45. You are troubleshooting a compressor that repeatedly trips the circuit breaker. The most likely problem is that the compressor motor

Explanation

The most likely problem is that the compressor motor has a grounded winding. When a motor winding is grounded, it means that there is a direct connection between the winding and the ground, causing a short circuit. This can result in excessive current flow, leading to the circuit breaker tripping as a safety measure to prevent damage or fire.

Submit
46. Before you start a reciprocating chiller, you must ensure that the oil level is at

Explanation

The correct answer is one-fourth to one-half of the sight glass. Before starting a reciprocating chiller, it is important to ensure that the oil level is within this range in the sight glass. This is because having the oil level too low can result in insufficient lubrication, leading to increased friction and potential damage to the chiller components. On the other hand, having the oil level too high can cause foaming and reduced efficiency. Therefore, maintaining the oil level between one-fourth to one-half of the sight glass is crucial for proper operation and longevity of the reciprocating chiller.

Submit
47. The box temperature for high-temperature refrigeration system start at

Explanation

The correct answer is 45*F. This is because high-temperature refrigeration systems typically require a higher starting temperature for the box temperature. Starting at 30*F would be too low and may not provide sufficient cooling, while starting at 50*F or 65*F would be too high and may result in overcooling or potential damage to the system. Therefore, 45*F is the most suitable starting temperature for a high-temperature refrigeration system.

Submit
48. When the compressor is off and the system is up to the highest point of its operating range, the evaporator coil pressure should correspond to the

Explanation

When the compressor is off and the system is up to the highest point of its operating range, the evaporator coil pressure should correspond to the air temperature in the box. This is because when the compressor is off, there is no refrigerant flow and therefore no pressure difference between the evaporator and condenser coils. The evaporator coil pressure will be equal to the pressure of the air inside the box, which is determined by the temperature of the air.

Submit
49. To check the relationship of the condensing refrigerant to the ambient air temperature, you would use

Explanation

To check the relationship of the condensing refrigerant to the ambient air temperature, you would use the high-side gauge readings. The high-side gauge measures the pressure of the refrigerant after it has been compressed by the compressor. By comparing the high-side gauge readings with the ambient air temperature, you can determine if the condensing process is occurring effectively. If the high-side gauge readings are too high or too low in relation to the ambient air temperature, it may indicate a problem with the condenser or other components of the refrigeration system.

Submit
50. What conditions are an indication of an overcharge in a system that is not equipped with an automatic expansion valve?

Explanation

When a system is not equipped with an automatic expansion valve, high suction pressure and high discharge pressure are indications of an overcharge. This means that there is an excessive amount of refrigerant in the system, causing the pressure to rise in both the suction and discharge lines. This can lead to inefficient cooling and potential damage to the system components.

Submit
51. What method would you use to measure the amount of refrigerant in a condenser?

Explanation

The subcooling method is used to measure the amount of refrigerant in a condenser. Subcooling refers to the process of cooling the refrigerant below its saturation temperature. By measuring the temperature of the refrigerant at the condenser outlet and comparing it to the saturation temperature, the subcooling value can be determined. This value is then used to calculate the amount of refrigerant present in the condenser.

Submit
52. What is the most likely problem if the temperature difference between the inlet and the outlet water in a water-cooled is lower than normal?

Explanation

If the temperature difference between the inlet and outlet water in a water-cooled system is lower than normal, it suggests that there is too much water flow. This means that the water is passing through the system too quickly, not allowing enough time for it to properly cool down. As a result, the temperature difference between the inlet and outlet water is reduced. To rectify this issue, the water flow needs to be adjusted to a more appropriate level to ensure efficient cooling.

Submit
53. What conditions are an indication of a low charge in a system that is not equipped with an automatic expansion valve?

Explanation

A low charge in a system without an automatic expansion valve can be indicated by low suction pressure and low discharge pressure. This means that there is not enough refrigerant in the system to maintain proper pressure levels during operation. Low suction pressure indicates a lack of refrigerant entering the compressor, while low discharge pressure suggests a reduced amount of refrigerant being pumped out of the compressor. Both of these conditions point towards a low charge in the system.

Submit
54. If there is an internal refrigerant leak from the high-pressure side to the low-pressure side of a system, the discharge gas temperature will

Explanation

If there is an internal refrigerant leak from the high-pressure side to the low-pressure side of a system, the discharge gas temperature will go up. This is because the leak causes a loss of refrigerant, which leads to a decrease in the amount of refrigerant available for the system to cool down. As a result, the remaining refrigerant will have to work harder to maintain the desired cooling effect, leading to an increase in the discharge gas temperature.

Submit
55. What condensing temperature is normally maintained to obtain adequate pressure drops across an expansion valve?

Explanation

To obtain adequate pressure drops across an expansion valve, a condensing temperature of 105°F is normally maintained. The pressure drop across the expansion valve is necessary for the refrigerant to undergo a phase change from a high-pressure liquid to a low-pressure vapor, which allows for cooling. If the pressure drop is too low, the refrigerant may not fully vaporize, leading to inefficient cooling. Conversely, if the pressure drop is too high, it can cause issues such as excessive noise, vibration, or even damage to the expansion valve. Therefore, maintaining a condensing temperature of 105°F helps to achieve the optimal pressure drop for efficient cooling.

Submit
56. When the temperature of a refirgerateed space goes down, the compressor will have

Explanation

When the temperature of a refrigerated space goes down, the suction gas inside the compressor becomes thinner. This means that there is a decrease in the density of the gas. As a result, the compressor will have less capacity because the thinner gas will have a lower mass flow rate, leading to a decrease in the cooling capacity of the system. Therefore, the correct answer is less capacity because the suction gas gets thinner.

Submit
57. Which thermostat terminal passes power to the heat relay?

Explanation

The W terminal passes power to the heat relay.

Submit
58. To maintain 75 percent humidity in a refrigeration system with a temperature range of 25 to 45*F, the appropriate coil-to-air temperature would be

Explanation

To maintain 75 percent humidity in a refrigeration system with a temperature range of 25 to 45°F, the appropriate coil-to-air temperature would be 16 to 22°F. This range allows for the cooling of the air without causing excessive condensation, which could lead to moisture-related issues. By keeping the coil-to-air temperature within this range, the system can effectively maintain the desired humidity level while also preventing any potential problems associated with excessive moisture.

Submit
59. What is the normal temperature difference between the inlet and the outlet water on s wastewater water-cooled condenser?

Explanation

The normal temperature difference between the inlet and outlet water on a wastewater water-cooled condenser is 10°F. This means that the outlet water is typically 10°F cooler than the inlet water. This temperature difference is important for the efficient operation of the condenser, as it allows for effective heat transfer and cooling of the wastewater.

Submit
60. What problems can a high-efficiency water filtration system cause for an ice machine?

Explanation

A high-efficiency water filtration system can cause problems for an ice machine by decreasing the conductivity of the water. This can lead to issues such as poor ice quality, slower ice production, and potential damage to the ice machine components. Lower conductivity water may not be able to effectively transfer heat, affecting the ice-making process. Additionally, decreased conductivity can also impact the taste and clarity of the ice produced. Therefore, while high-efficiency water filtration systems are important, they can have negative effects on ice machines if they decrease the water conductivity.

Submit
61. Which thermostat terminal passes power to the indoor fan?

Explanation

The G terminal on a thermostat is responsible for passing power to the indoor fan. When the thermostat calls for the fan to turn on, it sends a signal to the G terminal, which then activates the fan relay and allows power to flow to the fan. This terminal is commonly used in heating and cooling systems to control the operation of the fan.

Submit
62. When the thermal bulb of an expansion valve is loose from the suction line, you would expect the

Explanation

When the thermal bulb of an expansion valve is loose from the suction line, it can result in a loss of refrigerant flow control. This means that less refrigerant will be allowed into the evaporator coil, resulting in reduced cooling capacity. As a result, the suction line, which carries the cool refrigerant from the evaporator to the compressor, will be colder than normal. This is because there is less refrigerant flowing through the system to absorb heat from the surroundings.

Submit
63. If the condenser in a refrigeration system cannot remove the heat from the refrigerant, the

Explanation

If the condenser in a refrigeration system cannot remove the heat from the refrigerant, it will cause a buildup of pressure in the system. This is because the heat cannot be dissipated, leading to an increase in the discharge pressure.

Submit
64. A compressor that is not pumping to full capacity will have

Explanation

When a compressor is not pumping to full capacity, it means that it is not able to draw in and compress the refrigerant effectively. This results in high suction pressure, as the compressor is struggling to pull in enough refrigerant. On the other hand, the head pressure, which is the pressure of the refrigerant leaving the compressor, will be low because the compressor is not able to compress the refrigerant properly. Therefore, the correct answer is high suction and low head pressure.

Submit
View My Results

Quiz Review Timeline (Updated): Oct 22, 2024 +

Our quizzes are rigorously reviewed, monitored and continuously updated by our expert board to maintain accuracy, relevance, and timeliness.

  • Current Version
  • Oct 22, 2024
    Quiz Edited by
    ProProfs Editorial Team
  • Dec 02, 2012
    Quiz Created by
    Enorab
Cancel
  • All
    All (64)
  • Unanswered
    Unanswered ()
  • Answered
    Answered ()
After you have disabled a motor disconnect, you lock and tag the...
A short circuit will occur in the windings of a motor when the...
You should never use hand tools in a
Which fan circuit contacts must be closed to pass power to the fan...
What type of electrical problems will a hermetic compressor have?
Most assemblies are held on the motor shaft by
You are preparing to troubleshoot a system for an electrical problem....
When does the outdoor unit on a heat pump act as an evaporator?
What is used to supplement the unit when the outdoor temperature drops...
What type of switch is used to prove there is water flow in both the...
You turn the indoor fan switch on a thermostat to the FAN ON position....
When a partial restriction occurs in the liquid line, the point of the...
If the motor drive pulley and the driven pulley are out of line,...
To check for a short circuit from a motor winding to ground, you would...
Before you start the compressor on a centrifugal chiller, you must...
Which terminals would you use to determine why a thermostat does not...
You have removed and recovered the refrigerant from a system and...
When an exact replacement compressor for a refrigerator cannot be...
A run capacitor on an eletric motor is constructed as a
A motor that has a bad run capacitor
The three components that operate in the cooling mode are the
Mechanical motor problems normally occur at the
You make a continuity check on a compressor. The check indicates that...
The motor problems that can occur inside a hermetic compressor are
 What is the possible cause when a motor will not start, hums and...
What should be done to water chillers during the winter?
A start capacitor on an eletric motor is constructed as a
Which is designed to stop the defrost cycle of a low-temperature...
The temperature range of a refrigeration system depends upon the
The most probable causes of an inefficient evaporator are
After you have cleaned the tubes in a condenser, how would you check...
Which is an indication that the defrost system is not operating...
To safely check an electrical component for continuity or resistance,...
Most manufacturers illustrate the wiring in their equipment through...
To verify that the refrigerant is boiling at the correct temperature...
Calculate the discharge pressure for an R–502 system operating...
An oil sample from the crankcase of a centrifugal compressor should be...
You use your volt-ohm-milliammeter to check a transformer. You find it...
You can reduce the danger involved in attaching high-pressure gauges...
A single-phase condition in a three-phase motor can be caused by
What is the normal maximum reduction of temperature in a cooling tower...
On a trouble call, you determine that voltage is present from R to Y...
The function of the indoor coil on a heat pump unit is to
A refrigerator may have condensation (sweat) on the outside of the...
You are troubleshooting a compressor that repeatedly trips the circuit...
Before you start a reciprocating chiller, you must ensure that the oil...
The box temperature for high-temperature refrigeration system start at
When the compressor is off and the system is up to the highest point...
To check the relationship of the condensing refrigerant to the ambient...
What conditions are an indication of an overcharge in a system that is...
What method would you use to measure the amount of refrigerant in a...
What is the most likely problem if the temperature difference between...
What conditions are an indication of a low charge in a system that is...
If there is an internal refrigerant leak from the high-pressure side...
What condensing temperature is normally maintained to obtain adequate...
When the temperature of a refirgerateed space goes down, the...
Which thermostat terminal passes power to the heat relay?
To maintain 75 percent humidity in a refrigeration system with a...
What is the normal temperature difference between the inlet and the...
What problems can a high-efficiency water filtration system cause for...
Which thermostat terminal passes power to the indoor fan?
When the thermal bulb of an expansion valve is loose from the suction...
If the condenser in a refrigeration system cannot remove the heat from...
A compressor that is not pumping to full capacity will have
Alert!

Advertisement