Topics: All categories in the pool
1: An azeotropic refrigerant is
- a mixture of two or more refrigerants that boil at about the same temperature minimizing temperature glide.
- a mixture of two or more refrigerants that boil at much different temperatures causing temperature glide
- a mixture of two or more refrigerants that boil at much different temperatures minimizing temperature glide
- none of the above
2: Sensible heat is the heat added to a substance to
- change its state
- cause evaporation
- raise its temperature
- freeze it
3: Which of the following is NOT a positive displacement compressor?
- reciprocating
- scroll
- screw
- centrifugal
4: What refrigerant doesn't have to be classified?
- R-717
- R-422A
- R-718
- R-134A
5: System design pressures must take into consideration, not only, pressures found during normal operation but also what?
- When it's cold out
- When there is a malfunction on the high side
- When its warm out
- All of the above
6: What is the purpose of a surge capacitor on a contactor?
- to protect low voltage equipment
- to balance the sine waves
- to keep the contactor pulled in
- to provide smoother start/stops
7: Low ambient controls are used when
- on air conditioning systems only
- always
- economizers are used
- when systems run all year round
8: Large Mercantile occupancy is a premise or that portion of a premise where more than ____ persons congregate on levels above or below the street level to purchase personal merchandise.
- 250
- 100
- 350
- 400
9: Which winding have the most turns?
- they have equal amount of turns
- depends on the motor phase
- Start
- run
10: What is the minimum size of the discharge pipe?
- Same size as the outlet of the relief valve
- One pipe size larger that the inlet of the relief valve
- Depends on size of manifold
- All of the above
11: A run capacitor is wired in series with the _____ windings.
- common
- run
- start
- start capacitor
12: Halo-carbon refrigerants cannot be used with what material?
- Copper
- Magnesium alloy
- Aluminum
- Stainless Steel
13: How many forces operate a thermostatic expansion valve?
- 2
- 4
- 3
- 1
14: Large mercantile occupancy is
- a premise of that portion of a premise where more than 100 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise or that portion of a premise where more than 1500 persons congregate on levels above or below street level to purchase personal merchandise
- a premise of that portion of a premise where more than 50 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise or that portion of a premise where more than 200 persons congregate on levels above or below street level to purchase personal merchandise
15: Can ammonia be used on domestic system?
- yes
- yes, for systems under 10 tons
- no, unless there is proper ventilation system installed
- no
16: In a refrigeration system, you open a valve from the condenser and collect some material on a clean white sheet of bond paper, which of the following would you most likely be testing for?
- checking the level of refrigerant in the system
- testing for oil in the system
- testing for moisture in the system
- none of the above
17: If a purge unit fails on a low pressure chiller, what are the symptoms?
- high head pressure
- increased capacity
- low suction pressure
- low pressure chillers do not have purge units
18: According to the 522 CMR Board of Boilers, refrigerant detectors, alarms, and the refrigeration mechanical room ventilating systems shall be tested
- regularly
- bi-annually
- quarterly
- annually
19: If the compression ratio on a centrifugal compressor rises too high, the compressor will stop pumping and make a loud sound commonly referred to as a
- surge
- merge
- splurge
- purge
20: The solution that leaves the concentrator in an absorption chiller is referred to as the
- strong solution
- absorbed solution
- diluted solution
- weak solution
21: A thermometer inside a duct measures ____ heat.
- latent
- sensible
- specific
- hidden
22: A machine room with a refrigerant system using ammonia shall
- be provided with a continuously operated ventilation system
- be considered a non-hazardous location in accordance with National Electrical code
- have no flame producing apparatus permanently installed and operated
- All of the above
23: In an air conditioning plant which an indirect low side, water is used inside of bring: the proper sequence of operating the plan is
- start the fan and circulating pump
- reset the expansion valve
- reset the safety valve
- start the comrpessor
24: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
- 6.6 lbs
- 44 lbs
- 22 lbs
- 13.9 lbs
25: What should not (and can not) be located between a pressure imposing device and a pressure-limiting device?
- Stop valve
- Foot valve
- Muffler
- Moisture indicator