Topics: All categories in the pool
1: What is the maximum voltage range allowed on an electrical circuit?
- 15%
- 10%
- 20%
- 5%
2: When air is ducted through a machine room that services occupied space, What must be done?
- Ducted and sealed
- Welded and seamed.
- Insulated and cross broke
- Flanged and gasketed
3: R22 and 410A operate at the same range of condensing and evaporating temperatures
- true
- false
4: In an air conditioning system, the unit of total heat energy content in an air/vapor mixture is
- Enthalpy
- Specific heat
- Sensible heat
- Latent heat
5: What is R-22?
- Chlorofluoromethane
- HFC
- CCFCM
- Chlorodifluoromethane
6: 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
7: Horizontal piping should be run level.
- Yes, if the condenser is located above the evaporator
- True
- False
- No, unless the supervisor on the job says so.
8: What is not a requirement of a Class T machine room?
- Automatic ventilation
- Fire hose connected to the building fire protection system.
- Self-closing doors
- Tight fitting doors
9: Before replacing a seized compressor, the _______ should be determinded.
- designed head pressure
- type of refrigerant
- current draw
- cause of seizure
10: What type of pressure relief device is used on a CO2 system?
- Rupture disk
- Fusible plug
- Gate valve
- Glove valve
11: Fusible plugs must have what marked on them?
- Melting temperature in F
- Melting temperature in C
- Opening pressure
- All of the above
12: What kind of system uses two different refrigerants in separate systems dependent on each other?
- R-414B
- Simple
- Low pressure
- Cascade
13: Stop valves shall not be permitted between the system and the
- bleed valve
- relief valve
- condenser
- service valve
14: Who authorizes changes to the safety codes?
- Person who pulled the permit
- Board of Boilers
- Person in charge of the facility
- Contractor who last serviced the system.
15: What would be the classification of a church?
- Industrial
- Large mercantile
- Place of assembly
- Institutional
16: Evaporators within 18" of a heating coil must be equipped with a
- pressure relief device
- high limit control
- low limit control
- zone valve
17: High pressure controls should be set no higher than
- 80% of set point
- 10% of set point
- 25% of set point
- 90% of set point
18: What refrigerant doesn't have to be classified?
- R-717
- R-422A
- R-134A
- R-718
19: NH3 is
- ammonia
- lithium bromide
- R-718
- R-508A
20: Which of the following most closely represents the concentration of Li-Br in a absorption system?
- 40% Li-Br, 60% tap water
- 60% Li-Br, 40% distilled water
- 50% Li-Br, 50% tap water
- 40% Li-Br, 60% distilled water
21: Name three things that must be done when changing refrigeration lubricant?
- Nothing must be done
- Place sign, check for leaks, insulate
- Make sure it's compatible, notify owner, notify AHJ
- You can't change lubricants.
22: When this is installed on the high side of a system, it must be capable of reading 1.2 times the design pressure (ASHRAE 15 9.11.3)
- Pressure gauge
- Temperature gauge
- Sight glass gauge
- All of the above
23: Pressure vessels having design pressures of 15 psig or less shall have the strength to withstand at least ______times the design pressure.
- 3.0
- 2.5
- 5.5
- 2.0
24: Foaming of oil in a compressor is most likely to occur
- at start-up
- when the evaporator temperatures are below 32F
- when ambient temperature are low
- when there is insufficient air across the condenser(i.e., dirty coil)
25: Where are the three places that the discharge from an ammonia relief valve be piped?
- To chemical neutralizing tank only
- Underground, into drain, into mechanical room
- Atmosphere, Tank containing water, where the AHJ indicates.
- None of the above.