Chapter - 118,120 Flashcards
What are the three types of refrigeration controls?
Operating or primary
Actuating or secondary
Limiting and safety
What are the three controls for operating a compressor?
Temperature
pressure
humidity
What is the difference between cut in and cut out?
Temperature differential
What are the actuating controls?
Expansion valve and solenoid valves
What else are solenoid valves used with in flooded evaporators?
Low pressure float switches
Why can’t evaporator pressure dropped below a certain level?
Because it will form frosting on coils and freeze up the chiller
Where must a high pressure Cut out switch be placed
Before the first stop valve
Explain the function of accumulator
An accumulator is a simple trap on the suction line before the compressor which collects liquid and changes it to gas
What should the dial I’ll be pressure gauge be set at?
It is sometimes double but never less than 1.2 times the designed operating pressure
Explain the function of a oil separator
Oil separator should be placed on the discharge line immediately after the compressor and before the condenser to prevent oil coating
What are the two most common pressure relief devices?
Spring loaded relief valves and fusible plugs
What colour will a manual valve on the emergency discharge line be painted?
Red
