Topics: All categories in the pool
1: How can you test mechanical strength of an electrical connection?
- measure ohms with an electrical meter
- measure voltage across the connection
- attempt to pull the wire from the connector by hand
- none of the above.
2: Which refrigerant is lighter than air?
- R-134a
- R-123
- R-717
- R-11
3: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
- 44 lbs
- 22 lbs
- 13.9 lbs
- 6.6 lbs
4: The Department that certifies the transportation of refrigerant is the
- DOT
- RSES
- EPA
- EPO
5: If the power element on an expansion valve should lose its charge, the valve would
- Stay open
- Over feed
- Under feed
- Close
6: Materials used in construction and installation materials used in the manufacture or installation of refrigerating equipment shall be suitable for conveying refrigerant and the refrigerant oils and will not deteriorate in the presence of what?
- Water and soap
- Oil and water
- Moisture and air
- Air and dirt
7: The location of a thermal bulb of a TXV affects
- the amount of liquid refrigerant in the evaporator
- subcooling
- the amount of liquid in the condenser.
- the amount of liquid returning to the compressor
8: Setting a pressure relief device shall not exceed ___ of the design pressure
- 100%
- 90%
- 75%
- 80%
9: Ammonia belongs to Group
- A-2
- B-1
- A-1
- B-2
10: Pipe identification labels are required when the system contains more than
- 65 lbs
- 110 lbs
- 120 lbs
- 55 lbs
11: Dual-pressure relief devices should be installed on
- vessels of 3 cubic feet or more
- vessels of 10 cubic feet or less
- vessels of 10 cubic feet or more
- vessels of 3 cubic feet or less
12: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
- trichlorotrifluoromethane
- ammonia
- methyl chloride
- R-718
13: How many gallons of water do you need per pound of ammonia?
- 100
- 10
- 1
- 50
14: A mixed occupancy occurs when two or more occupancies are located with the same building
- true
- false
15: When using nitrogen for brazing, the pressure should be:
- Slightly below atmospheric
- Very low
- 50-100 psig
- 125 psig
16: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 22
- 50
- 18
- 33
17: The critical temperature of a refrigerant gas occurs when
- the gas is no longer saturated
- the gas returns to a liquid
- any increase in pressure will not liquefy the gas
- any decrease in pressure will cause condensation
18: What is the voltage of each leg of a 480 Volt three-phase motor?
- 208v
- 277v
- 240v
- 120v
19: Low pressure chiller systems use what type of compressor?
- Screw
- Reciprocating
- Scroll
- Centrifugal
20: Mercury was used in thermometers primarily because it
- vaporizes at very high temperatures
- expands uniformly
- never freezes
- was inexpensive
21: Crankcase heaters are energized
- to prevent compressor freeze-up
- to allow easy compressor start-up
- when the compressor is off
- while the compressor is running
22: In a system designed for sub-zero ambient temperatures, what must be added?
- Nitrogen
- Booster compressor
- Infrared dye for leak identification
- Low-ambient kit
23: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 75%
- 80%
- 90%
- 99%
24: Ashrae states that the equipment on a building needs to conform to adjacent buildings classifications when within ____ feet from opening and intakes.
- 20
- 75
- 50
- 15
25: A VRF system is a direct system
- true
- false