FINAL - Book 2 Review Flashcards
1
Q
1. The chilled water temperature switch will shut down the compressor if the temperature of the water leaving the chiller drops to approximately: A. 0°C – 0.5°C (32°F - 33°F) B. 1°C – 1.5°C (34°F - 35°F) C. 2.5°C - 3°C (36.5°F – 37.5°F) D. 1.5°C - 2°C (35°F – 35.5°F) E. 2°C – 2.5°C (35.5°F – 36.5°F)
A
C. 2.5°C - 3°C (36.5°F – 37.5°F)
2
Q
2. What brine temperature is used when cooling an ice surface? A. -11°C (12°F) B. -5°C (23°F) C. -18°C (0°F) D. -25°C (-13°F) E. -50°C (-58°F)
A
A. -11°C (12°F)
3
Q
3. What size packing should be used if the stuffing box bore on a pump is 63.5 mm (2.5 in.) and the shaft diameter is 50.8 mm (2 in.)? A. 12.7 mm (1/2 in) B. 19.05 mm (3/4 in) C. 9.525 mm (3/8 in) D. 6.35 mm (1/4 in) E. 4.76 mm (3/16 in)
A
D. 6.35 mm (1/4 in)
4
Q
4. The float rod should be adjusted so that it will close the inlet valve and shut off the water about \_\_\_\_\_ from the top of the overflow pipe. A. 6.4 mm (1/4 in) B. 12.7 mm (1/2 in) C. 25.4 mm (1 in) D. 19.1 mm (3/4 in) E. 31.7 mm (1 1/4 in)
A
C. 25.4 mm (1 in)
5
Q
5. Electrical control systems usually employ a normal line voltage of: A. 120 or 240 volts AC B. 120 or 240 volts DC C. 12 or 24 volts AC D. 12 or 24 volts DC E. 240 or 600 volts AC
A
A. 120 or 240 volts AC
6
Q
6. The sliding vane compressor may have a discharge pressure as high as: A. 3000 kPa (435 psi) B. 1000 kPa (145 psi) C. 5000 kPa (725 psi) D. 2000 kPa (290 psi) E. 4000 kPa (580 psi)
A
B. 1000 kPa (145 psi)
7
Q
7. A single-stage centrifugal compressor is one with a single impeller and may be able to compress atmospheric air to a pressure of about: A. 500 kPa (72.5 psi) B. 200 kPa (29 psi) C. 100 kPa (14.5 psi) D. 300 kPa (43.5 psi) E. 600 kPa (87 psi)
A
D. 300 kPa (43.5 psi)
8
Q
8. The circulator in smaller systems normally produces only a slight pressure differential and, even when it is placed in the return line, a pressure of \_\_\_\_\_ will ensure that sufficient positive pressure is maintained at the highest points in the system. A. 25 kPa (4 psi) B. 83 kPa (12 psi) C. 55 kPa (8 psi) D. 10 kPa (1.5 psi) E. 100 kPa (15 psi)
A
B. 83 kPa (12 psi)
9
Q
9. Steam in a two-pipe, vacuum return system is supplied pressures up to: A. 75 kPa (10 psi) B. 50 kPa (7 psi) C. 200 kPa (30 psi) D. 103 kPa (15 psi) E. 15 kPa (2 psi)
A
D. 103 kPa (15 psi)
10
Q
- The water pressure in most a hot water heating system is in between:
A. 85 kPa to 140 kPa (12.3 psi to 20.3 psi)
B. 75 kPa to 110 kPa (10.9 psi to 16 psi)
C. 250 kPa to 300 kPa (36.3 psi to 43.5 psi)
D. 100 kPa to 150 kPa (14.5 psi to 21.8 psi)
E. 70 kPa to 94 kPa (10.2 psi to 13.6 psi)
A
A. 85 kPa to 140 kPa (12.3 psi to 20.3 psi)
11
Q
11. Ordinarily, the most economical group relamping period is about \_\_\_\_\_ of rated life of the lamp. A. 100% B. 60% C. 90% D. 50% E. 70%
A
E. 70%
12
Q
12. The CSA B52 Mechanical Refrigeration Code requires that the pressure limiting device be designed to stop the action of the compressor or generator at a pressure not more than \_\_\_\_\_ of the system high side design pressure. A. 80% B. 100% C. 70% D. 90% E. 60%
A
D. 90%
13
Q
13. The closed expansion tank in hot water heating system has a gauge glass showing the level of water and air in the tank and would normally be from \_\_\_\_\_ the capacity of the tank. A. 1/8 to 1/3 B. 1/4 to 1/2 C. 1/2 to 2/3 D. 1/2 to 3/4 E. 3/4 to 7/8
A
C. 1/2 to 2/3
14
Q
14. The Hartford loop prevents steam pressure from forcing boiler water back into the return line should the: A. Boiler pressure get to high B. Feedwater supply fail C. Check valve fail to close D. Water level get to high E. Boiler temperature be to high
A
C. Check valve fail to close
15
Q
- Which of the following statements about centrifugal pumps is false?
A. Never run the pump in a dry condition even for a few minutes
B. Vent any air present from the seal housing before start up
C. Make sure an adequate flow of cooling liquid is flowing to the seal
D. Start the pump with the inlet valve closed
E. Start the pump with the discharge valve closed
A
D. Start the pump with the inlet valve closed
16
Q
16. Possible causes of a centrifugal pump discharge pressure being too low may include all of the following except: A. Speed too low B. Worn wearing rings C. Damaged impeller D. Worn packing E. Impeller diameter too large
A
E. Impeller diameter too large
17
Q
- The rotary screw compressor features two intermeshing rotors contained within a close-fitting casing the:
A. Male rotor is usually the driven one
B. Female rotor has six concave flutes
C. Rotors do not come in contact with each other so internal lubrication is not required.
D. Male rotor has four concave lobes
E. Female rotor is driven by means of timing gears
A
D. Male rotor has four concave lobes
18
Q
- A heat exchanger is used in a compression refrigerating system to transfer heat to the:
A. Cold vapour being drawn from the evaporator
B. Hot vapour being drawn from the evaporator
C. Cold vapour being drawn from the condenser
D. Hot vapour being drawn from the condenser
E. Cold liquid being drawn from the evaporator
A
A. Cold vapour being drawn from the evaporator
19
Q
19. In a typical electric control system the electric current is transmitted through a wire called the \_\_\_\_\_ to the burner. A. Neutral line B. Positive loop C. Negative loop D. Control link E. Connecting link
A
E. Connecting link
20
Q
- A pump is a mechanism that is used to _____ by imparting energy to the liquid being transferred.
A. Transfer a fluid from one place to another
B. Develop a static suction pressure
C. Raise a fluid from a lower level to a higher level
D. Create a pressure differential only
E. Raise a fluid from a higher level to a lower level
A
A. Transfer a fluid from one place to another
21
Q
- Mechanical seals have all the following advantages over packing except that they:
A. Are less expensive than packing
B. Requires less maintenance
C. Do not produce wear on shafts
D. Reduce leakage to a minimum
E. Can work under very high temperatures and pressures
A
A. Are less expensive than packing
22
Q
22. One of the methods employed to prevent backflow and control the cross connections is the: A. Air globe B. Reduced temperature principal device C. Double check breaker D. Temperature vacuum breaker E. Atmospheric vacuum breaker
A
E. Atmospheric vacuum breaker
23
Q
- Which of the following should not be included in the routine operation of a hot water heating system?
A. Test the safety relief valve on a regular basis
B. Keeping the boiler room and boiler clean and tidy
C. Keep covers on all controls
D. Make sure that the air supply to the boiler room is closed
E. Test the controls on a regular basis
A
D. Make sure that the air supply to the boiler room is closed