Deck 15: Truck Trailer Refrigerant Flow Control

Question 1

How does refrigerant enter the end cap section of the 3-way valve in the cool mode?

A) Through the pilot solenoid
B) Through the condenser pressure bypass check valve
C) Through the bleed passage
D) Through the discharge check valve

Answer 1

C

Question 2

In reference to the solenoid control refrigeration system what condition and state is the refrigerant in when it is forced through the bypass check valve?

A) High pressure superheated refrigerant
B) Low pressure subcooled refrigerant
C) High pressure subcooled refrigerant
D) Low pressure superheated refrigerant

Answer 2

A

Question 3

When the solenoid control system is in the heat mode what component helps to control the discharge pressure?

A) The quench valve
B) The high pressure switch working with solenoid valve number 2
C) The bypass check valve
D) Both components in answers A and B help to control compressor discharge pressure

Answer 3

D

Question 4

The large spring contained in the 3-way valve will always try to shift the valve:

A) To the cool position
B) To the heat position
C) To the defrost position
D) To the high speed heat mode

Question 5

What is the purpose of the condenser pressure bypass valve?

A) To increase condenser pressure.
B) To ensure condenser pressure does not exceed discharge pressure.
C) To allow refrigerant to flow through the bleed passage and through to the pilot solenoid.
D) To help the 3-way valve shift into the heat mode.

Question 6

When any refrigeration unit is in the heat mode of operation the flow of refrigerant is:

A) From the compressor discharge to the evaporator
B) From the compressor discharge to the condenser
C) From the compressor discharge to the heat exchanger
D) From the compressor discharge to the accumulator

Question 7

What happens when the 3-way valve shifts into the heat position?

A) The pilot solenoid valve is de-energized and the refrigerant pressure in the end cap is reduced to compressor suction pressure.
B) The pilot solenoid valve is energized and the refrigerant pressure in the end cap is reduced to compressor suction pressure.
C) The spool valve inside the 3-way valve shifts to seal the evaporator side.
D) Superheated refrigerant is routed directly into the condenser.

Question 8

How is refrigerant forced from the receiver tank in the heat mode?

A) It is pulled out by suction pressure
B) It is forced out by solenoid valve number 2
C) It is forced out by refrigerant that is forced through the bypass check valve
D) The receiver tank outlet valve closes forcing refrigerant for the receiver back through the bypass check valve

Question 9

Some solenoid systems us a component called a subcooler. What is the purpose of this component?

A) To add more heat to the refrigerant.
B) To increase operating efficiency by reducing flash gas at the TXV.
C) To superheat the refrigerant.
D) To reduce the temperature of the engine coolant.

Question 10

How many refrigerant check valves are used on the solenoid control refrigeration system?

A) 1
B) 2
C) 3
D) 4

Question 11

What valve causes the 3-way valve to shift into the heating position?

A) The solenoid valve number 1
B) The solenoid valve number 3
C) The pilot solenoid valve
D) The discharge check valve

Question 12

Where is the 3-way valve located?

A) Just downstream of the condenser
B) Just downstream of the drier
C) Just downstream of the discharge vibrasorber
D) Just downstream of the evaporator

Question 13

A solenoid control system may use a component called a quench valve. What is the purpose of this valve?

A) To increase refrigerant discharge pressure.
B) To increase refrigerant suction pressure.
C) To cool the compressor.
D) To help the system operate more efficiently.

Question 14

Check valves are used in the refrigeration system to route refrigerant in only one direction. On the refrigeration system that uses the 3-way valve how may check valves are used within the system?

A) 1
B) 2
C) 3
D) 4

Question 15

In what mode of operation is the pilot solenoid not energized?

A) The low speed heat mode
B) The low speed cool mode
C) The defrost mode
D) The high speed heat mode