Refrigeration Control Circuits Quiz Pt1

What is the purpose of a thermostat in a refrigeration system?

• To control the flow of refrigerant in the system

• To prevent the compressor from starting too soon after shutting off

• To maintain stable temperature conditions in a space

• To regulate the flow of electricity in the control circuit

Answer explanation

The purpose of a thermostat in a refrigeration system is to maintain stable temperature conditions in a space.

What type of thermostat uses mechanical gear to operate a switch for starting or stopping cooling equipment?

• Electromechanical thermostat

• Thermo disk thermostat

• Constant cut in thermostat

• Electronic thermostat

Answer explanation

The correct answer is the Electromechanical thermostat, which uses mechanical gear to operate a switch for starting or stopping cooling equipment.

What is the purpose of the controller differential in a thermostat?

• To minimize the overshoot and undershoot of temperature variations

• To maintain the space temperature at an acceptable value

• To initiate a corrective action when the control point is above the setpoint

• To prevent the compressor from starting too soon after shutting off

Answer explanation

The purpose of the controller differential in a thermostat is to minimize the overshoot and undershoot of temperature variations.

What type of thermostat uses semiconductors to change their resistance?

• Electronic thermostat

• Thermo disk thermostat

• Electromechanical thermostat

• Constant cut in thermostat

Answer explanation

The correct type of thermostat that uses semiconductors to change their resistance is the electronic thermostat.

What is the function of a pressure control in HVAC/R?

• To maintain stable temperature conditions in a space

• To rely on changes in pressure to operate an internal switch

• To control the flow of refrigerant in the system

• To regulate the flow of electricity in the control circuit

Answer explanation

The function of a pressure control in HVAC/R is to rely on changes in pressure to operate an internal switch, allowing it to regulate the system based on pressure variations.

What is the purpose of a relay in a refrigeration circuit?

• To maintain stable temperature conditions in a space

• To regulate the flow of electricity in the control circuit

• To control the flow of refrigerant in the system

• To initiate a corrective action when the control point is above the setpoint

Answer explanation

The purpose of a relay in a refrigeration circuit is to regulate the flow of electricity in the control circuit.

What is the function of a defrost time clock in a refrigeration system?

• To initiate a defrost cycle to control heaters that melt frost and ice from the evaporator

• To maintain the space temperature at an acceptable value

• To regulate the flow of electricity in the control circuit

• To prevent the compressor from starting too soon after shutting off

Answer explanation

The function of a defrost time clock in a refrigeration system is to initiate a defrost cycle to control heaters that melt frost and ice from the evaporator.

What is the purpose of a solenoid valve in a refrigeration system?

• To initiate a corrective action when the control point is above the setpoint

• To control the flow of refrigerant in the system

• To rely on changes in pressure to operate an internal switch

• To maintain stable temperature conditions in a space

Answer explanation

The purpose of a solenoid valve in a refrigeration system is to control the flow of refrigerant in the system.

What is the function of a defrost heater in a refrigeration system?

• To regulate the flow of electricity in the control circuit

• To control the flow of refrigerant in the system

• To maintain stable temperature conditions in a space

• To heat the evaporator to clear frost and ice build-up

Answer explanation

The function of a defrost heater in a refrigeration system is to heat the evaporator to clear frost and ice build-up.

What is the purpose of a crankcase heater in a refrigeration system?

• To maintain the space temperature at an acceptable value

• To heat the oil in the compressor crankcase

• To prevent the compressor from starting too soon after shutting off

• To initiate a corrective action when the control point is above the setpoint

Answer explanation

The purpose of a crankcase heater in a refrigeration system is to heat the oil in the compressor crankcase.