Test Bank: Modern Refrigeration and Air Conditioning,
21st Edition by Althouse - Chapters 1-55,
9781635638776 | Rationals Included
Electrical Circuits contain what? - ANSWER: A power source, a switch, and an electrical load
The electrical load is most often a _________. - ANSWER: Motor
Electrical power to the unit is obtained through an _________ _________ _______. - ANSWER:
Insulated Electrical Cord
Most electrical systems are a combination of what? - ANSWER: Parallel and Series Circuits switching
on and off electrical loads.
Devices that control conditions within a specified area are often called? - ANSWER: Operating
Controls
Refrigeration and Air conditioning control systems are often divided into what three categories? -
ANSWER: Conditioned area, Controlling Instrument, and Operating Device.
What is a closed-loop, or feedback, control system? - ANSWER: A system that is constantly correcting
the condition
The three types of mechanisms used in motor control thermostats are? - ANSWER: The Sensing Bulb,
Bimetal, and Solid State
What do bimetal strip temperature control devices consist of? - ANSWER: Two different metals that
are bonded together.
Copper has a greater coefficient of __________ than steel. - ANSWER: Expansion
The mercury switch is most often used on? - ANSWER: Air conditioning and heating thermostats
What are some advantages of electronic controls? - ANSWER: Reliable, compact, rapid response
times, and lack of moving parts
What is usually the sensing device in an electronic temperature control? - ANSWER: Thermistor
If the resistance of the thermistor goes down as temperature increases, it has a negative _________
_________. - ANSWER: Temperature Coefficient
What is the range adjustment mechanism? - ANSWER: an adjustable force pressing directly upon the
bellows or diaphragm which operates the switch
The range adjustment is commonly what? - ANSWER: A spiral spring with an adjustable screw
Some controls have a ______ ______ _____. The heat from this unit keeps the bellows and diaphragm
from becoming too cold. - ANSWER: Small heating unit
, Some differential adjustments have _______ that affect the movement of the bellows either just
before the contact points cut out, or cut in, but not both. - ANSWER: Springs
It is advisable to adjust controls as the ___________ specifies. - ANSWER: Manufacturer
What is the Cut-in type differential adjustment? - ANSWER: Cut-in point may be moved without
changing the cutout
What is the cutout type differential adjustment? - ANSWER: The cutout point may be moved without
changing the cut-in setting.
What is the double type differential adjustment? - ANSWER: The cut-in and cutout settings may be
brought closer together or moved farther apart.
Contact points may ________ as they open or close. - ANSWER: Chatter
Refrigeration systems that contain a sensing bulb type thermostat calibrated at ____ _____ may be
too cold at elevations above 5000 feet. - ANSWER: Sea level
At _____ ______ the atmospheric pressure drops then the pressure on the control diaphragm or
bellows is lowered enough to affect the settings on refrigeration temperatures. - ANSWER: High
altitude
Automatic refrigeration and air conditioning is designed to provide correct temperatures with the
______ ________. - ANSWER: Least attention
Most refrigerator manufactures design their units to operate only 8 to __ hours out of each 24. -
ANSWER: 14
Domestic refrigerators usually run 5 to 10 minutes and are idle 10 to __ minutes. - ANSWER: 20
Comfort cooling air conditioners have two standard controls: the thermostat and the _______
________. - ANSWER: Defrost Control
The defrost control prevents ice formation the air conditioner __________. - ANSWER: Evaporator
What does Central air conditioning imply? - ANSWER: The system can provide heating, cooling,
humidification, dehumidification, and in many systems electrostatic air cleaning.
Automatic _____________ controls usually govern the flow of water or steam into a humidifier. -
ANSWER: Humidification
The ________ _______, which usually operate from a room thermostat, govern the running time of
the heating device. - ANSWER: Heating controls
Cooling is usually controlled by a ______ ________. - ANSWER: Room thermostat
What do electrostatic air cleaners do? - ANSWER: Air being drawn through the air conditioner gets
"scrubbed" while passing through the device.
The _______ in ice maker controls senses the amount of time required to freeze the ice cubes and
start the harvest cycle. - ANSWER: Sensor
In ice maker controls the commutator and _____ _______ moves the mechanism through the refill,
freezing, and harvest operation - ANSWER: brush assembly
21st Edition by Althouse - Chapters 1-55,
9781635638776 | Rationals Included
Electrical Circuits contain what? - ANSWER: A power source, a switch, and an electrical load
The electrical load is most often a _________. - ANSWER: Motor
Electrical power to the unit is obtained through an _________ _________ _______. - ANSWER:
Insulated Electrical Cord
Most electrical systems are a combination of what? - ANSWER: Parallel and Series Circuits switching
on and off electrical loads.
Devices that control conditions within a specified area are often called? - ANSWER: Operating
Controls
Refrigeration and Air conditioning control systems are often divided into what three categories? -
ANSWER: Conditioned area, Controlling Instrument, and Operating Device.
What is a closed-loop, or feedback, control system? - ANSWER: A system that is constantly correcting
the condition
The three types of mechanisms used in motor control thermostats are? - ANSWER: The Sensing Bulb,
Bimetal, and Solid State
What do bimetal strip temperature control devices consist of? - ANSWER: Two different metals that
are bonded together.
Copper has a greater coefficient of __________ than steel. - ANSWER: Expansion
The mercury switch is most often used on? - ANSWER: Air conditioning and heating thermostats
What are some advantages of electronic controls? - ANSWER: Reliable, compact, rapid response
times, and lack of moving parts
What is usually the sensing device in an electronic temperature control? - ANSWER: Thermistor
If the resistance of the thermistor goes down as temperature increases, it has a negative _________
_________. - ANSWER: Temperature Coefficient
What is the range adjustment mechanism? - ANSWER: an adjustable force pressing directly upon the
bellows or diaphragm which operates the switch
The range adjustment is commonly what? - ANSWER: A spiral spring with an adjustable screw
Some controls have a ______ ______ _____. The heat from this unit keeps the bellows and diaphragm
from becoming too cold. - ANSWER: Small heating unit
, Some differential adjustments have _______ that affect the movement of the bellows either just
before the contact points cut out, or cut in, but not both. - ANSWER: Springs
It is advisable to adjust controls as the ___________ specifies. - ANSWER: Manufacturer
What is the Cut-in type differential adjustment? - ANSWER: Cut-in point may be moved without
changing the cutout
What is the cutout type differential adjustment? - ANSWER: The cutout point may be moved without
changing the cut-in setting.
What is the double type differential adjustment? - ANSWER: The cut-in and cutout settings may be
brought closer together or moved farther apart.
Contact points may ________ as they open or close. - ANSWER: Chatter
Refrigeration systems that contain a sensing bulb type thermostat calibrated at ____ _____ may be
too cold at elevations above 5000 feet. - ANSWER: Sea level
At _____ ______ the atmospheric pressure drops then the pressure on the control diaphragm or
bellows is lowered enough to affect the settings on refrigeration temperatures. - ANSWER: High
altitude
Automatic refrigeration and air conditioning is designed to provide correct temperatures with the
______ ________. - ANSWER: Least attention
Most refrigerator manufactures design their units to operate only 8 to __ hours out of each 24. -
ANSWER: 14
Domestic refrigerators usually run 5 to 10 minutes and are idle 10 to __ minutes. - ANSWER: 20
Comfort cooling air conditioners have two standard controls: the thermostat and the _______
________. - ANSWER: Defrost Control
The defrost control prevents ice formation the air conditioner __________. - ANSWER: Evaporator
What does Central air conditioning imply? - ANSWER: The system can provide heating, cooling,
humidification, dehumidification, and in many systems electrostatic air cleaning.
Automatic _____________ controls usually govern the flow of water or steam into a humidifier. -
ANSWER: Humidification
The ________ _______, which usually operate from a room thermostat, govern the running time of
the heating device. - ANSWER: Heating controls
Cooling is usually controlled by a ______ ________. - ANSWER: Room thermostat
What do electrostatic air cleaners do? - ANSWER: Air being drawn through the air conditioner gets
"scrubbed" while passing through the device.
The _______ in ice maker controls senses the amount of time required to freeze the ice cubes and
start the harvest cycle. - ANSWER: Sensor
In ice maker controls the commutator and _____ _______ moves the mechanism through the refill,
freezing, and harvest operation - ANSWER: brush assembly
