Chapter 11 review

Which of the following is an advantage of using a digital thermostat over a mechanical thermostat?

• More accurate temperature control

• Easier to read display

• Many have programmable functions

• All of the choices are correct

Which of the following thermostat terminals will be used to control the second stage of cooling in a staged system?

• Y1

• Y2

• W2

• X2

An electrical device that opens and closes a set of contacts when a certain pressure is applied to the diaphragm refers to a _____________________.

• Pressure switch
• Pressure transducer

• Pressure modulator

• Thermostat

An electrical device that responds to changes in temperature by opening and closing describes a ___________________?

• Thermostat

• Pressure switch

• Thermistor

• Rheostat

An electro-magnetic coil that produces a magnetic field to pull a steel core into the field to open or close a valve best describes a(n) ____________________.

• Solenoid valve

• Electronic actuator

• Pressure relief valve

• Service valve

Electronic thermostats sense the temperature by using a semiconductor device called a ________________.

• Transistor

• Thermocouple

• Thermistor

• Transducer

Low-pressure switches are connected to the ________________________.

• Discharge side of the refrigeration system

• Condenser side of the refrigeration system

• Suction side of the refrigeration system

• Liquid-line on the refrigeration system

Low-voltage thermostats used in air conditioning typically operate on which of the following voltages?

• 12 volts

• 24 volts

• 50 volts

• 120 volts

Thermostats are used in which of the following applications?

• Heating and air conditioning

• Commercial refrigeration

• Thermal limits for safety

• All of the choices are correct

To protect the equipment, a high-pressure switch used as a safety device must shut the equipment down by ________________________.

• Closing on rise of pressure

• Opening on rise of pressure

• Modulating on rise of pressure

• Opening on fall of pressure