Cooling System Controls: Types, Design, and Installation

Question 1

What type of control is commonly used to regulate airflow in a duct system?

Accepted Answer

Damper

Answer

Pressure switch

Answer

Safety limit switch

Answer

Thermostat

Question 2

A thermostat's primary function in a cooling system is to control:

Accepted Answer

Temperature

Answer

Airflow

Answer

Refrigerant flow

Question 3

What is the purpose of a pressure switch in a refrigeration system?

Accepted Answer

To monitor and protect the system from high or low pressure conditions.

Answer

To control the airflow in the duct system.

Answer

To regulate the speed of the compressor.

Question 4

Which control system offers the most precise and customizable temperature regulation in a building?

Accepted Answer

Programmable thermostat

Answer

Simple on/off switch

Answer

Manual thermostat

Answer

Pneumatic control system

Question 5

A high-pressure cut-out switch in a cooling system is designed to do what in case of a malfunction?

Accepted Answer

Shut down the compressor to prevent damage.

Answer

Reduce the refrigerant flow rate.

Answer

Adjust the thermostat's temperature setpoint.

Answer

Increase airflow to dissipate heat.

Question 6

What type of control is typically used to regulate the speed of a variable-speed compressor?

Accepted Answer

Electronic control module (ECM)

Answer

Pressure switch

Answer

Thermostat

Answer

Damper

Question 7

The primary purpose of a control panel in a cooling system is:

Accepted Answer

To provide a central location for monitoring and adjusting system settings.

Answer

To store refrigerant for the system.

Answer

To filter the air entering the system.

Question 8

When installing a new control system, what is the most crucial factor regarding the existing system?

Accepted Answer

Compatibility with existing wiring and components.

Answer

The brand of the control system.

Answer

The aesthetic appearance of the control panel.

Answer

The cost of the control system.

Question 9

Why is a cooling system with a manual control system typically less efficient than one with an automated system?

Accepted Answer

Manual systems require constant adjustments and may not respond quickly to changing conditions.

Answer

Manual systems are prone to more frequent breakdowns.

Answer

Manual systems are more expensive to install.

Question 10

Which of the following is NOT a common type of control used in cooling systems?

Accepted Answer

Capacitor bank

Answer

Safety limit switch

Answer

Pressure switch

Answer

Thermostat

Question 11

What is the primary function of a thermostat in a cooling system?

Accepted Answer

It senses the room temperature and controls the cooling system to maintain the desired setpoint.

Answer

It adjusts the speed of the compressor motor.

Answer

It regulates the pressure of the refrigerant in the system.

Answer

It measures the flow rate of refrigerant.

Question 12

Which type of control system uses a variable-speed compressor to maintain a more consistent temperature?

Accepted Answer

Inverter-driven system

Answer

Mechanical thermostat system

Answer

Pressure-operated switch system

Answer

On/Off control system

Question 13

What is the primary purpose of a low-pressure control switch in a cooling system?

Accepted Answer

To protect the compressor from damage due to low refrigerant levels.

Answer

To control the speed of the condenser fan motor.

Answer

To regulate the flow of refrigerant to the evaporator.

Question 14

When installing a new thermostat, which of these factors is most crucial for accurate temperature readings?

Accepted Answer

Avoiding direct sunlight and drafts

Answer

Installing it near a heat source for faster response

Answer

Placing it as high as possible on the wall

Question 15

Which type of control is commonly used to prevent a furnace and air conditioner from operating simultaneously?

Accepted Answer

Interlocking relay

Answer

Thermocouple

Answer

Capacitor

Question 16

What is the main function of a zoning system in a cooling system?

Accepted Answer

It allows for different temperature settings in different areas of a building.

Answer

It increases the overall efficiency of the cooling system.

Answer

It reduces the need for regular maintenance.

Question 17

A homeowner complains about uneven cooling in their house. Which control system issue could be the cause?

Accepted Answer

Faulty zone dampers

Answer

Low refrigerant charge

Answer

Oversized condenser unit

Answer

Dirty air filter

Question 18

What control device is directly responsible for turning the condenser fan motor on and off?

Accepted Answer

Condenser fan motor control

Answer

Compressor contactor

Answer

Evaporator coil sensor

Answer

Blower motor resistor

Question 19

How does a variable-refrigerant flow (VRV) system differ from a traditional cooling system in terms of control?

Accepted Answer

VRV systems use multiple indoor units with individual temperature control.

Answer

VRV systems use only mechanical controls.

Answer

VRV systems do not require thermostats for operation.

Question 20

What is the primary purpose of a defrost control in a heat pump system?

Accepted Answer

To prevent ice buildup on the outdoor coil during the heating cycle.

Answer

To control the speed of the blower motor.

Answer

To regulate the flow of refrigerant to the indoor coil.

Question 21

Which type of control is responsible for maintaining a set point temperature in a cooling system?

Accepted Answer

Thermostat

Answer

Condenser

Answer

Compressor

Answer

Evaporator

Question 22

What is the purpose of a pressure switch in a cooling system?

Accepted Answer

To protect the compressor from damage due to high or low pressure conditions.

Answer

To regulate the flow of refrigerant.

Answer

To control the fan speed.

Question 23

A blower motor control is typically used to:

Accepted Answer

Adjust the speed of the blower motor based on the cooling demand.

Answer

Regulate the refrigerant flow.

Answer

Monitor the temperature of the condenser coil.

Question 24

Which of the following is NOT a common type of thermostat used in residential cooling systems?

Accepted Answer

Programmable Logic Controller (PLC)

Answer

Mechanical thermostat

Answer

Smart thermostat

Answer

Digital thermostat

Question 25

How does a low-pressure switch protect a cooling system?

Accepted Answer

By shutting off the compressor if refrigerant pressure drops below a safe level.

Answer

By regulating the refrigerant flow.

Answer

By increasing the fan speed to compensate for low pressure.

Question 26

When installing a thermostat, it's crucial to ensure:

Accepted Answer

It is located in a representative area where temperature is accurately reflected.

Answer

It is mounted close to the compressor unit.

Answer

It is positioned near a heat source.

Question 27

A cycling control is primarily used to:

Accepted Answer

Control the on/off operation of the compressor based on temperature fluctuations.

Answer

Regulate the refrigerant flow.

Answer

Monitor the pressure of the system.

Question 28

What is the main purpose of a safety control in a cooling system?

Accepted Answer

To prevent damage to the system and ensure the safety of occupants.

Answer

To regulate the flow of refrigerant.

Answer

To improve the efficiency of the system.

Question 29

What is the primary function of a humidistat in a cooling system?

Accepted Answer

To control the humidity level of the conditioned space.

Answer

To monitor the temperature of the evaporator coil.

Answer

To regulate the refrigerant flow.

Question 30

Which type of refrigeration system control is responsible for sensing changes in indoor air temperature and adjusting cooling output accordingly?

Accepted Answer

Thermostat

Answer

Expansion valve

Answer

Evaporator coil

Question 31

What is the primary purpose of an expansion valve in a refrigeration system?

Accepted Answer

To regulate the flow of refrigerant and maintain system pressure

Answer

To compress the refrigerant vapor

Answer

To extract heat from the indoor air

Question 32

Which component acts as a safety device in a cooling system, protecting against excessive pressure buildup?

Accepted Answer

Pressure relief valve

Answer

Thermostat

Answer

Condenser

Answer

Evaporator

Question 33

What is the function of a capillary tube in a refrigeration system?

Accepted Answer

To restrict refrigerant flow and regulate system pressure

Answer

To cool the refrigerant

Answer

To filter contaminants from the refrigerant

Question 34

Which type of control is used to maintain a constant temperature in a cold storage room?

Accepted Answer

Proportional-integral-derivative (PID) controller

Answer

Float switch

Answer

Time delay relay

Answer

On/off controller

Question 35

What is the purpose of a low-pressure switch in a refrigeration system?

Accepted Answer

To prevent compressor damage by halting operation when system pressure drops below a safe level

Answer

To regulate refrigerant flow

Answer

To control fan speed

Question 36

Which type of sensor is commonly used to monitor indoor humidity levels in a cooling system?

Accepted Answer

Humidistat

Answer

Thermistor

Answer

Pressure transducer

Answer

Flow switch

Question 37

What is the role of a time delay relay in a cooling system?

Accepted Answer

To delay the activation or deactivation of other controls to prevent rapid cycling

Answer

To monitor system pressure

Answer

To regulate refrigerant temperature

Question 38

Which type of control is used to limit the maximum speed of a fan in a cooling system?

Accepted Answer

Fan speed controller

Answer

Expansion valve

Answer

Thermostat

Answer

Float switch

Question 39

What is the primary function of a check valve in a cooling system?

Accepted Answer

To prevent refrigerant backflow and maintain system pressure

Answer

To regulate refrigerant temperature

Answer

To detect leaks