Quiz 1

Question 1

Air circulation in the icebox is accomplished by the use of which of the following?

Answer 1

diffuser fans

Option B is correct.

Question 2

The cooling-water side of the condenser should be opened for inspection every _______.

Answer 2

six months

Question 3

Some causes of a noisy compressor are _______.

Answer 3

worn bearing, pins, etc.

Question 4

If the thermal expansion valve becomes inoperative, the iceboxes will have to be controlled by the _______.

Answer 4

manual expansion valve

Question 5

Sweating of the crankcase is caused by which of the following?

Answer 5

too much oil in the system

Question 6

Which of the following is the usual cause of slugging?

Answer 6

expansion valve not operating properly

Question 7

What operates the low-pressure cutout switch?

Answer 7

bellows

Question 8

Which of the following must be checked if an automatic Freon system will not start up?

Answer 8

all of these

Question 9

Which of the following is the probable cause of hot suction line?

Answer 9

insufficient refrigerant

Question 10

What do you call the device that is used as a low-pressure control and high-pressure cutout on a compressor?

Answer 10

pressure controller

Question 11

If the solenoid valve closed by accident, the compressor would be stopped by which of the following?

Answer 11

low-pressure cutout switch

Question 12

The purpose of the low-pressure cutout switch is to _______.

Answer 12

cut compressor in and out at a preset pressure

Question 13

If the cooling water to the condenser suddenly fails, _______.

Answer 13

the compressor will shut down

Question 14

The most likely cause of high superheat would be _______.

Answer 14

expansion valve closed too much

Question 15

What do you call the liquid reaching the compressor through the suction?

Answer 15

flooding back

Question 16

The suction pressure switch is operated by which of the following?

Answer 16

pressure on a bellows

Question 17

If the compressor short-cycles on the high-pressure cutout, which of the following would you check?

Answer 17

all of these

Question 18

A Freon unit will tend to short-cycle when operating under _______.

Answer 18

light loads

Question 19

Air is removed from the system by _______.

Answer 19

opening the purge valve

Question 20

Short-cycling means that the machine _______.

Answer 20

stops and starts frequently

Question 21

The suction pressure in a Freon system should be _______.

Answer 21

the pressure which corresponds with a temperature equal to the temperature of the icebox

Question 22

If any of the electrically controlled devices in a Freon system malfunction, which of the following valve will also automatically shut off?

Answer 22

Solenoid valve

Question 23

A leaky discharge valve can usually be detected by _______.

Answer 23

any of these

Question 24

The dehydrating agent in a Freon system is usually _______.

Answer 24

activated alumina

Question 25

If the compressor short-cycles on the low-pressure cutout, the trouble might be _______.

Answer 25

any of these

Question 26

If an electrically operated compressor failed to start, the cause might be _______.

Answer 26

any of these

Question 27

The high-pressure side of the system is sometimes referred to as the _______.

Answer 27

hot side

Question 28

If the compressor were to run continuously without lowering the temperature, the trouble would probably be _______.

Answer 28

any of these

Question 29

Which of the following would cause a high head pressure?

Answer 29

insufficient cooling water

Question 30

If frost forms on the cylinders, the cause would be _______.

Answer 30

expansion valve open too wide

Question 31

Which of the following would cause low head pressure?

Answer 31

B and C

Question 32

Too high suction pressure could be caused by _______.

Answer 32

any of these

Question 33

Which of the following would cause high head pressure?

Answer 33

any of these

Question 34

An excessively high head pressure could be caused by _______.

Answer 34

insufficient cooling water to the condenser

Question 35

Which of the following would cause a high suction pressure?

Answer 35

expansion valve open too wide

Question 36

If a compressor runs continuously, the cause might be a _______.

Answer 36

stuck low-pressure switch

Question 37

Low suction pressure is caused by _______.

Answer 37

air in the system

Question 38

How is a Freon system purged?

Answer 38

the same as a CO2 system

Question 39

If the compressor discharge temperature is higher than the receiver temperature, _______.

Answer 39

increase the amount of cooling water to the condenser

Question 40

How is a CO2 system purged?

Answer 40

when CO2 comes out of the purge valve, frost will form on a piece of metal held near the outlet

Question 41

If the head pressure is too high, _______.

Answer 41

the high-pressure cutout switch should operate before the relief valve opens

Question 42

The system should be purged _______.

Answer 42

after the system has been shut down for a few hours

Question 43

If the compressor had been running satisfactorily for a long period of time but suddenly the compartment temperature started to rise, the trouble must be _______.

Answer 43

any of these

Question 44

If the compressor had been running satisfactorily for a long period of time but the oil level was rising slowly, one should _______.

Answer 44

shut down the compressor and check the oil level with the machine stopped

Question 45

The purpose of the trap is _______.

Answer 45

to remove oil from the refrigerating gas

Question 46

Too much oil in the compressor would _______.

Answer 46

damage the expansion valve

Question 47

The oil level in the compressor should be checked _______.

Answer 47

after a long period of operation

Question 48

The agent used in an indirect reefer system is _______.

Answer 48

A or C

Question 49

Air can be prevented from getting into the system by _______.

Answer 49

keeping all glands and stuffing boxes on the high-pressure side tight

Question 50

Which of the following would not cause high suction pressure?

Answer 50

suction valve not adjusted properly