Topics: All categories in the pool
1: A motor is rated for 120 volts and has a RLA (rated-load amps) of 5 amps. What is the wattage of the motor?
- 600 watts
- 5KW
- 1000 watts
- 746 watts
2: The actual expansion curve of compression follows most nearly which one of the following curves?
- Adiabatic
- Isothermal
- Pressure Temperature
- Volume Temperature
3: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
- the aggregate of the high side and low side
- the high side
- the low side
- 2.5 times the design pressure
4: Control systems can be classified by
- safety
- economy of operation
- source of power
- tonnage of system
5: High side floats are used on centrifugal chiller systems are are considered critically charged systems.
- are obsolete.
- True
- depends on the type of refrigerant being used
- False
6: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
- 77F
- 58F
- 70F
- 32F
7: Megaohm meter's main function is
- to detect weak motor winding insulation of a refrigeration or air conditioning compressor by creating high DC voltages to the compressor
- to detect very high resistances to ground of refrigeration or air conditioning compressors
- to test very high value capacitors for large 3-phase refrigeration compressors and blower motors.
- Both a and b are correct
8: Which is the lowest vacuum?
- 5" hg
- 1,000 Microns
- 5 psig
- 10 psia
9: A Lithium-bromide system is an absorption system that
- uses salts as an absorbent and lithium bromide as a refrigerant
- uses water as a refrigerant and lithium bromide as an absorbent
- uses ammonia as a refrigerant and lithium bromide as an absorbent
- uses water as a absorbent and lithium bromide as a refrigerant
10: A micron is
- one thousandths of a millimeter
- one millonths of a micrometer
- one millonths of a centimeter
- a larger unit of measurement than Hg
11: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
- 1%
- 25%
- 2%
- 4%
12: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- System operating pressure will drop
- The Li-Br solution will become more diluted
- The Li-Br solution will become more concentrated
- Rust can form
13: Liquid level gauges must be provided with what?
- Automatic shut-offs
- A relief valve
- A low level mark
- A red line
14: What is not a requirement of a Class T machine room?
- Self-closing doors
- Fire hose connected to the building fire protection system.
- Tight fitting doors
- Automatic ventilation
15: How many refrigerant classifications are there for toxicity?
- 1
- 2
- 5
- 3
16: On a single phase motor, when does the start winding cut out?
- At 25% of its full rated speed
- At 75% of its full rated speed
- At 50% of its full rated speed
- Start windings do no cut-out of the run cycle
17: Which refrigerant is lighter than air?
- R-717
- R-123
- R-11
- R-134a
18: The generator shell contains the
- condenser and the absorber
- condenser, the evaporator, and the generator
- condenser and the generator
- evaporator and the absorber
19: Fusible plugs shall not be used with pressure vessels of
- 3 cubic feet or less
- 15 square feet or less
- 3 cubic feet or more
- 15 cubic feet or more
20: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
- Low suction pressure and low discharge pressure
- High head pressure and low suction pressure
- High suction pressure and high discharge pressure.
- Low head pressure and high suction pressure
21: Class 3 refrigerants are
- non-toxic
- highly flammable
- non-flammable
- toxic
22: Which occupancy can ammonia be used in?
- redifential
- depends on the quantity of freon
- commercial
- industrial
23: 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.
- Lithium bromide
- HCFC-123
- ammonia
- CFC-11
24: What refrigerant is an inorganic compound?
- R-410A
- Ammonia
- R-132A
- R-22
25: What device should be used on low-temperature freezers?
- hot-gas by-pass
- high capacity TXV
- discharge muffler
- oil separator