HVAC Chapter 53

The 3 way valve ____________ in a stand alone reefer unit.

• reverses the refrigeration cycle

• permits pressure checking

• reverses compressor rotation

• is used to defrost the evaporator

A 3 position service valve that is front seated allows ________________.

• compressor isolation

• normal system operation

• pressure testing

• total system evacuation

A 3 position service valve that is back seated allows ________________.

• for normal operation

• compressor isolation

• system pressure testing

• total system evacuation

A 3 position service valve that is mid seated allows ________________.

• total system evacuation

• compressor isolation

• non operational mode

• system pump down

The defrost cycle can begin with all the following EXCEPT?

• driver activation

• temperature differential sensed

• timer

• evaporator temperature

Which of the following is not a mode of the self powered reefer unit?

• standby

• defrost

• cooling

• heating

All of the following are true concerning reefer trailers EXCEPT?

• they contain a fuel tank

• they are often painted a dark color to reduce attracting sunlight

• they contain batteries

• they have insulated walls and roof

All of the following are true concerning reefer trailers EXCEPT?

• they have a monitoring system containing lights to alert the driver

• they use R404a refrigerant

• they must be connected to the truck during the refrigeration process

• they can be aluminum colored to reflect sunlight

Reefer trailers usually have ______ cylinders arranged in a/an _________configuration.

• 4, V

• 4, inline

• 3, inline

• 3, V

R404a reefer systems use ____________ refrigeration oil.

• POE

• PAG

• CFC

• mineral