Accessories Flashcards
What do compressor protection devices monitor ?
- Current draw on compressor motor
- Head pressure
- Temperature of the compressor done
- Temperature of the discharge line
What is mounted to the compressor shell near the motor terminals to prevent over heating ?
Thermal overload device
What does a discharge line pressure switch do ?
Turns off system if head pressure gets to high
What is a discharge line thermostat ?
Senses discharge line temperature and (opens on rise in temperature) to turn off the system
What in an accumulator helps to return oil to the compressor ?
Aspirator
What is a thermal insulator ?
Oil
What is an oil separator
Removes oil from high pressure refrigerant Vapor. Diameter is larger than the discharge line.
Oil level regulator does what ?
Oil control device that regulates the level of oil within a compressor using a float mechanism
Oil safety control does what ?
Will shut off electrical power to the compressor if oil pressure drops below normal for a certain period of time.
Explain EPRV
Open on rise of inlet pressure
Prevent evaporator pressure from falling below a predetermined value.
(Can operate multiple boxes with different set points)
Explain CPRV
(Close on rise of outlet pressure)
Set to limit the suction pressure to a pre determined maximum.
Explain Distributor tubes
Distribute refrigerant in parallel passes minimizing pressure drop.
Medium and large sized coils.
Explain hot gas bypass valve
Method of capacity control.
(Impose a false load on the evaporator allowing some hot discharge gas to enter after the TXV)
Explain impingement oil separator
Impingement oil separators use screens in the upper half to cause fine particles of oil to collect and form larger ones.
Explain helical oil separator
Depend on the interior shell design to force gas/oil mixture along a spiral path. Creates centrifugal force which forces oil to outside and collect/drain to the float valve
