Topics: All categories in the pool
1: A mercury bulb controller is not recommended for
- low voltage use
- line or low voltage use
- use where vibration is severe
- line voltage use
2: Give an example of a secondary coolant?
- R-718
- R-717
- R-12
- R-410A
3: In an electrical circuit, what is potential measured in?
- Herys
- Ohms
- Volts
- Amps
4: R-11 has the greatest corrosive effect on
- Bronze
- Aluminum
- Magnesium
- Copper
5: The outer portion of shell of the compressor used on low-pressure chillers is called the
- suction
- baffle
- nozzle
- volute
6: Who is permitted to access a refrigeration machine room?
- Contractors only
- Anyone, it's a completely safe area
- Authorized persons only
- Any employee
7: Fractionation occurs when
- the pressures decreases as the heat load decreases
- the pressures increase as the heat load increases
- when a fraction of refrigerant is added as the full charge
- some of the blended refrigerant evaporates or condenses before the rest of the blend
8: What type of relief valve is used on a CO2 system?
- rupture disc
- fusible plug
- gate valve
- glove disc
9: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Wet bulb temperature
- Saturated temperature
- Dry bulb temperature
- Critical temperature
10: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
- motor starter
- printed circuit board (PCB)
- duel-voltage switch
- centrifugal switch
11: 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
12: How many flammability classifications are refrigerants in?
- 7
- 2
- 3
- 5
13: A 24 volt transformer with a 240 volt primary can handle how many amps?
- There isn't enough information to answer.
- 10 amps
- 20 amps
- 24 amps
14: Heat that changes the physical state of a substance without effecting a change in its temperature is known as
- latent heat
- lost heat
- specific heat
- sensible heat
15: 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.
- CFC-11
- ammonia
- Lithium bromide
- HCFC-123
16: Suction line oil traps should be installed when the condenser is
- in the basement and the evaporator is on the third floor
- more than 100' away from the evaporator
- on the third floor roof and the evaporator is in the basement
- located outside the operates in temperatures below 35F
17: Electricity involves the movement of electrons in atoms
- True
- False
18: What do you need to do when you install a new system?
- Add refrigerant
- Insulate the suction line before you take a superheat reading
- Have it inspected
- Document the superheat and subcooling reading
19: What is potential measured in?
- Henrys
- Ohms
- Volts
- Amps
20: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.
- 24
- 18
- 15
- 10
21: When the compressor is below the condensor
- traps are not needed on this type of system
- traps are needed on the discharge line
- traps are needed on the suction line
- traps are needed on the oil return line
22: What is considered a cooling agent?
- any liquid used for the transmission of heat when condensation occur
- any liquid used for the transmission of heat without condensation
- any liquid used for the transmission of heat without vaporization
- any liquid used for the transmission of heat when vaporization occurs
23: 746 watts is equal to
- 1 hp
- Pi
- 100 hp
- 10 hp
24: Pressure vessels with an internal volume of 3 cubic feet or less
- shall use pressure relief devices
- shall use pressure relief devices or fusible plugs
- shall use fusible plugs
- do not need pressure relief protection
25: Which refrigerant replaced R-12?
- R-407A
- R-22
- R-410A
- R-134A