Topics: All categories in the pool
1: On a centrifugal compressor, stationary diffuser vanes are needed to
- increase the clearance space
- stop gas flow
- convert velocity energy to pressure
- prevent high pressure on the packing
2: Oils, classified as to source, are
- naphthalene, mixed, and paraffin
- animal, vegetable, and castor
- animal, vegetable, and mineral
- naphthalene, paraffin, and castor
3: Fusible plugs shall not be used with pressure vessels of
- 15 cubic feet or more
- 3 cubic feet or more
- 15 square feet or less
- 3 cubic feet or less
4: How is bring measured?
- hydrometer
- manometer
- hygrometer
- anemometer
5: What is a megaohm meter?
- An electric meter that measures very high resistance values by sending a high DC voltage signal into the object being tested
- An electric meter that measures very high resistance values by sending a low voltage AC signal into the object being tested
- An electric meter used by electricians to test large 3-phase blower motors for the correct rotation
- Is an electric meter that measures extremely low resistance valves by sending high DC voltage signal into the object being tested.
6: R-717 is
- water
- carbon dioxide
- ammonia
- trichloromethane
7: When an electronic bridge is in balance the bridge output will be
- 0 volts
- 1 volt
- .01 volts
- 15 volts
8: The dial of a pressure gauge, when installed on the high side of a system be graduated 1.2 times the designed pressure.
- True
- False
9: All low-pressure chillers use which type of compressor?
- Reciprocating
- Scroll
- Centrifugal
- Rotary
10: Halogenated refrigerants cannot be used with what material?
- Stainless steel
- Magnesium alloy
- Copper
- Aluminum
11: A 120 volt motor rated at 1,800 watts. You find the motor is drawings 25 amps. The motor is
- drawing RLA and is running as it should
- drawing LRA and is seized and should be replaced.
- running hot
- none of the above
12: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
- the vapor side of the system
- low side of the system
- the liquid side of the system
- high side of the system
13: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
14: The gauge thickness required on a CO2 tank construction is
- 5/16"
- 3/32"
- 1/16"
- 1/8"
15: What would be the classification for Stop & Shop grocery store?
- Industrial
- Place of assembly
- Instituional
- Large mercantile
16: The evaporator is a device to
- remove heat from the refrigeration system
- Keep the compressor busy
- absorb heat into the refrigeration system
- store liquid refrigerant
17: Large vessels containing refrigerant ______________________ from using two or more pressure-relief devices in parallel to obtain the required capacity.
- of Group B2 refrigerant shall be prohibited
- containing R-11, R-123 & R-717 exclusively shall not be prohibited
- shall be prohibited
- shall not be prohibited
18: Can a R22 line set be reused for a 410A system and if it can be reused, what must be done to it?
- Flush with R-11
- Flush with RX-11
- Flush with ammonia
- Flush with R-718
19: What is used to check very low pressure?
- Velometer
- Hygrometer
- Manometer
- Hydrometer
20: The absorber shell contains the
- evaporator and the absorber
- condenser and the generator
- condenser, the evaporator, and the generator
- condenser and the absorber
21: Who is permitted to access a refrigeration machine room?
- Contractors only
- Anyone, it's a completely safe area
- Authorized persons only
- Any employee
22: Institutional occupancy is
- a premise or that portion of a premise where large numbers of people congregate and from which occupants cannot quickly vacate the space.
- a premise or that portion of a premise from which, because they are disabled, debilitated, or confined, occupants cannot readily leave without the assistance of others.
- a premise or that portion of a premise where people transact business, receive personal service, or purchase food and other goods.
- None of the above
23: A plug containing an alloy that will melt at a specific temperature to relief pressure is a
- fusion plug
- fusible plug
- rupture plug
- relief plug
24: Total heat of a substance is considered
- specific heat
- empathetical
- sensible heat
- enthalpy
25: R-12. R-22, and R-40 are considered Group I refrigerants.
- True
- False