Topics: All categories in the pool
1: Which of the following is an inorganic refrigerant?
- R-22
- Ammonia
- Chlorofluorocarbons
- All of the above
2: When air is ducted through a machine room that services occupied space, What must be done?
- Flanged and gasketed
- Insulated and cross broke
- Welded and seamed.
- Ducted and sealed
3: R-717 is
- carbon dioxide
- trichloromethane
- water
- ammonia
4: copper and its alloys shall not be used in contact with _____ except as a component of bronze alloys for bearing or other non-refrigerant containing uses.
- ammonia
- HCFC-123
- Lithium bromide
- CFC-11
5: If a liquid receiver is designed to receive the refrigerant charge during a pumpdown procedure, it shall have the capacity to
- receive the pumpdown charge
- release the charge when the pressure exceeds 310 psig or higher
- Pumpdown procedures are not allowed with systems containing liquid recievers
- hold up to 110% of the pumpdown charge
6: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.
- 1.2
- 2.2
- 1
- 1.5
7: Refrigerant is metered into the evaporator on a large centrifugal chiller thru the
- low side of the system
- high side float assembly
- cap tube
- none of the above
8: Class T machine room
- shall include closets used for setting equipment
- has no flame producing apparatus permanently installed
- shall have remote controls to stop the action of the refrigerant compressor
- shall have refrigerant leak detecting systems installed inside and outside the room
9: When an inspection is needed, how often must it be done?
- every 24 months
- annually
- every 36 months
- every 18 months
10: Megaohm meters can detect a ground in the
- 10,000,000 ohms or higher
- up to 1,000 ohms
- up to 1,000,000 ohms
- up to 10,000 ohms
11: Horizontal piping should be run level.
- No, unless the supervisor on the job says so.
- False
- Yes, if the condenser is located above the evaporator
- True
12: A pressure vessel having an inside diameter of 6” or less shall be sufficient to withstand ____times the pressure of the saturation temperature of the refrigerant or ____times the critical pressure of the refrigerant, whichever is less.
- 3.0, 3.5
- 2.5, 3.0
- 2.5, 2.5
- 6.6, 6.6
13: In a system designed for sub-zero ambient temperatures, what must be added?
- Booster compressor
- Infrared dye for leak identification
- Nitrogen
- Low-ambient kit
14: How many BTU's is produced by one watt of energy
- 1
- 3.41
- 3.00
- 2.57
15: If the suction pressure is low and the evaporator temperature high, the cause will be a?
- overcharged
- starved evaporator
- compressor suction valve stuck open
- too small evaporator
16: What is the minimum height refrigeration piping should be placed against walls?
- 6'
- 7.25'
- Ceiling height
- 72"
17: What device measures the specific gravity of a substance?
- Hydrometer
- Manometer
- Hygrometer
- Thermometer
18: Which of the following types of oils are hygroscopic?
- polyolester (POE)
- polyalkylene glycol (PAG)
- naphthene mineral
- both a and b
19: Group A3 refrigerants have a ______ flammability rating than Group B1 refrigerants
- the same
- higher
- there is no Group B1 refrigerants
- lower
20: Pressure vessels of 10 cubic feet or more gross volume shall use
- at least one rupture member
- a dual pressure-relief valve if charging into the atmosphere
- at least three means of discharge and/or rupture discs
- both a and b are correct
21: R-123 belongs to Group
- A-3
- B-3
- B-2
- B-1
22: How many flammability classifications are refrigerants in?
- 5
- 7
- 3
- 2
23: If a halide torch is used for leak detection, what color is the flame if it detects a leak?
- orange
- green
- blue
- red
24: The two float-type metering devices are the
- high-side float and the low-side float
- liquid float and the vapor float
- vapor float and the low-side float.
- liquid float and the low-side float
25: A 24 volt transformer with a 240 volt primary can handle how many amps?
- 10 amps
- There isn't enough information to answer.
- 20 amps
- 24 amps