Unit 1-10 Test (1020) Flashcards
The purpose of a TEV is to maintain a nearly constant _____ with varying loads on the evaporator.
superheat
The TEV feeds _____ refrigerant with an increase in load.
more
When the coil is flooded with refrigerant, the superheat is:
low
When a coil is starved for refrigerant, the superheat is:
high
The adjustment stem on a TEV would be turned _____ to increase superheat.
clockwise
The TEV sensing bulb is connected to the _____ of the evaporator coil.
outlet
Which of the following does not have a direct affect on the TEV’s operation?
Outdoor ambient temperature
Which type of system is considered to have a “Critical Charge”?
Cap Tube
A restriction in a cap tube can cause the evaporator to _____ when properly charged.
starve
A pump down procedure is started when the _____ valve is front seated.
liquid line
Which of the following could not be serviced when a system is pumped down?
Condenser
What may be used on an air cooled condenser with a fan to prevent the head pressure from becoming too low in mild weather?
Fan cycling or fan speed control (head pressure control system)
What does the compressor amperage when the head pressure rises?
Increase
What would the head pressure do if the condenser fan motor quit running?
Increase
A dirty evaporator coil would cause a ____ superheat.
High
An R22 system is operating with a low side pressure of 50 psig and high side pressure of 210 psig. The temperature at the outlet of the evaporator is 38 degrees Fahrenheit. What is the superheat?
12
Which type of compressor would not be for residential applications?
Centrifugal
A compressor designed so that suction gas flows around and through the motor would be considered primarily air cooled.
True or False?
False
Boiling temperature is _____ side pressure converted to temperature.
low
Condensing temperature is _____ side pressure converted to temperature.
high
A liquid receiver must be used with a capillary tube system.
True or False?
False
Which metering device is more economical and has no moving parts?
Cap Tube
Low superheat could cause:
both A and B (valve damage in compressor and rod or piston damage in compressor)
All TEV’s are adjustable.
True or False?
False
