Topics: All categories in the pool
1: What is a Category "M" fluid?
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and the designed temperature is between -20F to 366F
- A typical refrigerant used on newer air conditioning and heat pump systems
- A toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily content
- Any fluid that exceeds 150 psig and has design temperatures over 366F
2: Doors communicating with outside from a mechanical room must be?
- Self-closing, wooden, fire door
- Self-closing, aligned, fire door
- Steel, approved, weather-stripped
- Self-closing, approved, fire door
3: Ammonia systems use ____ pressure to adjust oil pressure
- discharge
- liquid
- air
- stream
4: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- nothing must be done
- place sign, check for leaks, insulate
- make sure it's compatible, notify owner, notify A.H.J
- you can't change refrigerants
5: Refrigerant piping crossing an open space that affords passageway in any building shall not be less than _____ feet above the floor unless piping is located against the ceiling.
- 7.25'
- 7.00'
- 9.00'
- 8'4"
6: What type of oil is used in R-410A systems?
- naphthene
- polyalkylene glycol (PAG)
- mineral oil
- polyolester (POE)
7: A check valve is a device
- designed to allow the flow of refrigerant gas in both directions
- that is always spring loaded
- with a pressure drop
- found on high pressure steam systems
8: The best way to determine the voltage requirement for an electrical component is to
- read the nameplate data
- determine the capacity of the service panel
- read the voltage with a mulitmeter
- check with the utility company
9: What type of pressure relief device is used on a CO2 system?
- Rupture disk
- Gate valve
- Fusible plug
- Glove valve
10: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
- High suction pressure and high discharge pressure.
- Low head pressure and high suction pressure
- High head pressure and low suction pressure
- Low suction pressure and low discharge pressure
11: Which of the following is an inorganic refrigerant?
- R-22
- Ammonia
- Chlorofluorocarbons
- All of the above
12: What device should be used on low-temperature freezers?
- discharge muffler
- high capacity TXV
- oil separator
- hot-gas by-pass
13: 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
14: Secondary refrigerants are usually
- water or brine
- Prestone anti-freeze
- alcohol
- expensive
15: Where are the three places that the discharge from an ammonia relief valve be piped?
- atmosphere, tank containing water, where the A.H.J. indicates
- underground, into drain, into mechanical room
- to chemical neutralizing tank only
- none of the above
16: R-11 belongs to Group
- A-1
- B-1
- B-3
- A-2
17: What are the three components of a transformer?
- Contacts, secondary coil, and core
- Primary coil, secondary coil, and core
- Primary coil, secondary coil, and copper contacts
- Primary core, secondary coil, and high and low voltage connectors.
18: What is not a requirement of a Class T machine room?
- Tight fitting doors
- Automatic ventilation
- Fire hose connected to the building fire protection system.
- Self-closing doors
19: A split-phase motor has a ______ winding and a ____ winding
- duel-run, duel-start
- run, start
- run, common
- start, common
20: Pressure vessels having an inside diameter of 6” or less shall be protected by
- either a fusible plug or a pressure relief device
- a fusible plug
- Pressure vessels having an inside diameter of 6” or less need no such protection unless otherwise specified
- a pressure relief device
21: A movie theater would be considered a
- commercial occupancy
- institutional occupancy
- mixed occupancy
- public assembly occupancy
22: Sublimation occurs when
- liquid is formed from a gas
- gas is formed directly from a solid
- gas is formed from a liquid
- ice melts and turns to water
23: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
- lift voltage
- boost voltage
- pick-up voltage
- run voltage
24: By using nitrogen within a pipe during brazing operation,
- Discoloration is prevented
- Exterior scale formation is minimized
- Copper oxide formation is prevented
- The explosion hazard is confined
25: The best way to detect ammonia in brine is
- carbonation of soda
- CO2 gas
- potassium of line
- nessler regaent