Topics: All categories in the pool
1: Which is considered the more efficient condenser?
- fan cooled
- water cooled
- spray cooled
- air cooled
2: What is the typical air conditioning operating pressures for R-22?
- 60 psi suction 210 psi discharge
- 25 psi suction 125 psi discharge
- 105 psi suction 340 psi discharge
- None of the above
3: Heat transferred by conduction from one body to another is done
- via heat rays
- via radiation
- via liquids
- via solids
4: What type of relief valve is used on a CO2 system?
- rupture disc
- glove disc
- gate valve
- fusible plug
5: Horizontal piping should be run level.
- Yes, if the condenser is located above the evaporator
- No, unless the supervisor on the job says so.
- True
- False
6: What type of copper is not permitted on refrigeration systems?
- Type M
- Type L
- Type K
- Type N
7: In a low temperature refrigeration system, the benefit of the system using P.A.G. oil is
- it is hydroscopic
- it traps moisture
- viscosity
- all of the above
8: An accumulator can be located between the
- evaporator and compressor
- condenser and evaporator
- compressor and condenser
- first stage and second stage compressors
9: If the power element on an expansion valve should lose its charge, the valve would
- Under feed
- Over feed
- Close
- Stay open
10: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?
- Low Pressure displacement
- Non-positive displacement
- Pressure induced displacement.
- Positive displacement
11: Stop valves shall not be permitted between the system and the
- bleed valve
- condenser
- service valve
- relief valve
12: What device should be used on low-temperature freezers?
- discharge muffler
- oil separator
- high capacity TXV
- hot-gas by-pass
13: How does a centrifugal compressor create the pressure differential needed to move refrigerant through the system?
- Nesting scrolls
- Fan-like action
- Rotating vanes
- Suction and discharge valves
14: A R-410A system running with a condensing temperature of 110F and 50F evaporator temperature will read pressures of ___ on the high side and ___ on the low side
- 455 psig, 185 psig.
- 365 psig, 120 psig
- 257 psig, 77 psig
- 226 psig, 68 psig
15: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- high pressure
- design pressure
- low pressure
- critical pressure
16: A direct system
- is one which encloses a separate body of evaporative refrigerant
- is where the refrigerant comes in contact with the space refrigerated
- is a self-contained complete factory made and tested system
- is on where brine is cooled & circulated to the space refrigerated
17: What section governs pressure vessels?
- Section 1 ASHREA 15 ASME fired
- OSHA
- Section 8 ASHREA 15 ASME unfired
- Section ASHREA 34
18: Ammonia is under what safety classification?
- B1
- B3
- B2
- A3
19: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
20: 1 HP = ____ Watts?
- 3.1416
- 11,239
- 746
- 3,412
21: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- make sure it's compatible, notify owner, notify A.H.J
- nothing must be done
- place sign, check for leaks, insulate
- you can't change refrigerants
22: Capacity control on an absorption system is typically accomplished by varying the
- rate at which heat is supplied to the generator
- speed of the chilled water circulatory pump
- pressure setting on the system's rupture disc
- speed of the condenser water circulator pump
23: The critical temperature of a refrigerant gas occurs when
- the gas returns to a liquid
- the gas is no longer saturated
- any increase in pressure will not liquefy the gas
- any decrease in pressure will cause condensation
24: R-22 is classified as a ____ refrigerant on the safety matrix.
- B-2
- A-1
- A-2
- B-1
25: The instrument used to measure the specific gravity of absorption chiller solutions is the
- hydrometer
- refractometer
- anemometer
- Psychrometer