What important functions does an air receiver perform? - ANSWER Dissipates heat,
Dampens compressor pulsations,
Act as water oil trap
On a compressed air system a safety valve would generally be installed on the? - ANSWER Air receiver
Variable air volume system? - ANSWER Typically use VFDs ...
What important functions does an air receiver perform? - ANSWER Dissipates heat,
Dampens compressor pulsations,
Act as water oil trap
On a compressed air system a safety valve would generally be installed on the? - ANSWER Air receiver
Variable air volume system? - ANSWER Typically use VFDs to save energy
In figure 1.3, a full call for cooling would be at what branch pressure to the damper motor? - ANSWER 3
psig
A ratio relay would be used to? - ANSWER Control the sequence of actuators
When an actuated device is said to be normally open, that means the device is open with? - ANSWER No
control pressure is applied
In figure 1.4, the hot water valve has an 8-12 psig spring range, the damper motor has a 3-5 psig spring
range. The calibration point of the thermostat is? - ANSWER 8 psig
When you are setting up an instrument, you should know all of the following except? - ANSWER The rate
of flow of the control agent
Which of the following is an example of a control with a readjusted set point? - ANSWER Submaster
controller
In figure 1.5, the branch pressure from the temperature controller increases the pressure as the? -
ANSWER Controlled variable decreases in Temperature
, The departure of the control point from the set point, or the amount of that departure is describe as ? -
ANSWER Deviation
A pneumatic controller takes air from the main at a ________ pressure and delivers it to the actuator at
a ____ pressure: - ANSWER Constant, variable
Current outputs produce ______ signal distortion over long wire distances. - ANSWER Low
A three-way diverting valve? - ANSWER Has to outlets and one common inlet
A normally closed pressure electric switch is made when? - ANSWER No air is applied to its bellows
In figure 1.4 the heating valve is piped ? - ANSWER Normally closed
The intensity of heat is expressed in the terms of? - ANSWER BTU's
Or
Degrees in Fahrenheit
Psychrometry refers to the relationship between? - ANSWER Temperature, pressure and moisture
content of air
An advantage of screw type compressors is that they? - ANSWER Deliver almost pulse-free flow
Which of the following is more advantageous for transmission of signals? - ANSWER Current signal
Refer to figure 1.2, contctor coil-1 pulls in an electric strip heater on a cold air duct to a room. The
pneumatic room thermostat operates ps-1. The thermostat action is what control action? - ANSWER
Reverse
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