ACR 202 week 11

The three types of compressors commonly used on chillers are the linear, reciprocating, and centrifugal.

• True

• False

Blocked suction cylinder unloading is accomplished by

• closing the discharge.

• keeping the suction valve closed.

• using a device in the low-pressure side of the system to close it off

Which of the following methods are used to control the capacity of a centrifugal compressor?

• Prerotation vane control

• Blocked discharge

• High- to low-side bypass

• Cylinder unloading

The compressor used in low-pressure chillers is the

• screw

• centrifugal.

  
  

• rotary

The subcooling temperature in a condenser can be measured by taking the difference between the

• condensing temperature and the entering-refrigerant temperature.

  
  

• suction pressure converted to temperature and the boiling refrigerant.

  
  

• condensing temperature and the leaving-refrigerant temperature.

Which of the following metering devices is used in low-pressure chillers?

• A low- or high-side float

• A capillary tube

• An automatic expansion valve

• A thermostatic expansion valve

The purge unit in a low-pressure chiller removes

• overcharge of refrigerant.

  
  

• excess oil.

• condensable refrigerant.

• noncondensables.

When water is cooled and circulated throughout the building to air-heat exchange coils, the water is referred to as a(n) __________.

• secondary refrigerant

• expendable refrigerant

• antifreeze

  
  

• refrigerant

The colder the water that is circulated in a chiller, ___________.

• the less efficient the chiller will be

• the more freeze protection is required throughout the system

• the smaller the terminals and piping are required to be

• the larger the terminals and piping are required to be

The evaporator of a chiller is also referred to as the ___________.

• indoor coil

  
  

• outdoor coil

  
  

• water box

• chiller barrel