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WorksheetsUA Local 467 Section 7.1 to 7.4 Quizizz
Total questions: 36
Worksheet time: 21mins
A(n) ____ control system is a control system in which compressed air is used to provide power for the control system.
self-contained
pneumatic
electrical
automated
The control of the environment in commercial buildings is based on energy efficiency and ____.
cost
comfort
size of the building
type of building
A pneumatic control system is a control system in which ____ is used to provide power for the control system.
fire
compressed air
electricity
natural gas
In the 1960s, ____ came into common use and was adapted for use in commercial HVAC control systems.
fluid power
electricity
compressed air (pneumatic) power
solid-state, low-voltage direct current (DC) devices
____ is a designation of the contaminants present in the air.
Pollution
Indoor air quality
Uncirculated air
Makeup air
(a) is a designation of the contaminants present in the air of a building space.
(a) is a condition that occurs when people cannot sense a difference between themselves and the surrounding air.
Accurate control of the environment in a building space leads to (a) occupancy rates and profits.
Early control of the level of comfort in a living environment was done by (a) .
Self-contained control systems are used to control basic closed loop systems that require relatively low accuracy.
A. Self-contained
B. Pneumatic
C. Electrical
D. Automated
The power to a self-contained control system is supplied by a sealed, ____.
A. duct
B. fluid-filled element
C. pump
D. thermostatic expansion valve
As the temperature of the fluid in a pipe or air in a building space changes, the heat transfer in a self-contained control system changes the ____ of the fluid in the power element.
A. pressure
B. temperature
C. volume
D. state
The two most common applications of self-contained control systems are ____ and building space temperature control in steam or hot water heating systems.
dampers
air compressors
thermostatic expansion valves
room thermostats
Most self-contained control systems have relatively poor ____.
power output
accuracy
pressure
voltage signals
Pressure acts against a ____ that moves a valve body to regulate the flow of refrigerant, steam, hot water, or chilled water through the valve.
switch
fluid-filled element (bulb)
bimetallic element
diaphragm
The fluid-filled element of a self-contained control system is known as a(n) (a) .
A self-contained control system is a control system that does not require a(n) (a) .
The disadvantages of (a) control systems are that they cannot be expanded to provide sophisticated control sequences because only one setpoint adjustment is provided.
Electrical control systems can use ___ to enable low-voltage control circuits to switch line-voltage devices.
relays
control devices
actuators
dampers
Humidity control is accomplished with a ___ that uses a moisture-sensing element to open or close a switch.
pressurestat
thermostat
humidistat
mercury bulb
___ are often used in industrial and commercial systems in which access by occupants is not possible.
Relays
ON/OFF switches
Auxiliary devices
Line-voltage controls
Electrical control systems are not often used for ___ control because only digital (ON/OFF) control devices are used.
open loop
proportional
humidity
temperature
Humidity control is accomplished with a(n) ___ that uses a moisture-sensing element to open or close a switch.
humidistat
mercury bulb thermostat
electronic sensor
A(n) (a) is a control system that uses electricity (24 VAC or higher) to operate the devices in the system.
A(n) (a) is a sensing device that consists of two different metals joined together.
(a) control devices are wired directly to the controlled devices such as compressors, fans, and pumps because both are at the same voltage level.
Modern thermostats use a(n) (a) to close or open a circuit to control the temperature in the space.
Thermostats are usually wired to a(n) (a) at the HVAC unit.
Pneumatic control systems can be separated into ___ main groups of components based on their function.
A. two
B. three
C. four
D. five
___ change or reroute the air supply from the transmitter or controller before it reaches the controlled devices.
A. Electric switches
B. Bleedports
C. Auxiliary devices
D. Dampers
A(n) ____ is an orifice that allows a small volume of air to be expelled to the atmosphere.
bleedport
exhaust port
damper
transmitter
Pneumatic control systems can be used in most control sequences because of their ____.
accuracy
power output
reliability
flexibility
A disadvantage of pneumatic control systems is that pneumatic air compressor stations require ____.
higher power supplies
regular maintenance
expensive piping and components
a single control sequence
(a) devices are devices that are normally located between the transmitters or controllers and the controlled device.
(a) control systems are rarely used in residential systems or packaged (rooftop or heat pump) units.
Pneumatic control systems can be separated into (a) main groups of components based on their function.
