Topics: All categories in the pool
1: The External equalizer of a TXV compensates for
- pressure within the evaporator
- pressure drop across the evaporator coil
- pressure drop across the condenser coil
- pressure within the system
2: A Category D fluid
- is when the fluid handled is non flammable, nontoxic, and not damaging to human as defined in ANSI/ASME Process Piping.
- is when the design pressure does not exceed 150 psi
- a fluid for service piping in which the potential for personnel exposure is judged to cause harm and irreversible damage to those persons exposed to it
- Both a and b are correct
3: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
4: What is absolute humidity?
- the amount of moisture in the air per one pound of 50% RH air
- the amount of moisture in the air in grains of cubic feet of volume
- the amount of moisture in the air in grains of square feet of volume
- none of the above
5: A compressor in which the increase in vapor pressure is attained without changing the internal volume of the compression chamber is called
- non-positive displacement compressor
- neutral chamber-type compressor
- non-volumetric displacement compressor
- negative displacement compressor
6: What is the purpose of a trap in a vertical discharge line with an upward flow?
- start the flow of oil throughout the system
- ensure proper oil return to the compressor
- Installing a vertical discharge line with an upward flow is prohibited by code
- None of the above
7: What type of voltage causes the winding in a potential relay to open?
- BEMF (Back Electro-Motive Force)
- 24V control voltage from the thermostat
- 120V line voltage
- None of the above
8: Booster compressors, pump refrigerant into the
- high side of the secondary compressor
- low side of the primary compressor
- heat & plate heat exchanges
- receiver
9: Liquid level gauges must be provided with what?
- A red line
- A relief valve
- Automatic shut-offs
- A low level mark
10: Pressure vessels shall be provided with ___________in accordance with Section VIII of the ASME Boiler & Pressure Vessel Code
- over pressure protection and a rupture disc
- over pressure protection as well as a temperature protection device
- over pressure protection
- Pressure vessels need no type of protection as long as it is hydrostatically tested every three months
11: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- you can't change refrigerants
- nothing must be done
- make sure it's compatible, notify owner, notify A.H.J
- place sign, check for leaks, insulate
12: What does “ultimate strength” mean?
- Design strength of the vessel or piping in a refrigeration system
- Stress at which rupture will occur
- Highest or design pressure allowed inside a machinery room
- None of the above
13: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
- low pressure
- design pressure
- high pressure
- critical pressure
14: R-410A can segregate in the system or chemically change its composition due to a leak.
- True
- False
15: Dew point is
- the temperature below which water vapor in the air will start to condense
- the temperature of air of 50% RH
- the temperature above which water vapor in the air will start to condense
- the temperature below which water vapor in the air will start to evaporate
16: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
- 550 lbs
- 55 lbs
- 330 lbs.
- 660 lbs
17: Copper and its alloys shall not be used with ammonia
- True
- False
18: The purpose of a receiver is
- a vessel to store refrigerant outside the system
- to increase the capacity that the system can hold
- to use a a later date
- all of the above
19: An oil pressure safety switch should be set at
- 10-15 psi above low side pressure
- 10 to 15 psi below low side pressure
- 5 to 10 psi above low side pressure
- 5 to 10 psi below low side pressure
20: Electricity involves the movement of electrons in atoms
- True
- False
21: 14.7 psia is equivalent to
- atmospheric pressure at seal level
- 29.92" Hg
- 0 psig
- All of the above.
22: Pressure vessels having design pressures of 15 psig or less shall have the strength to withstand at least ______times the design pressure.
- 2.5
- 3.0
- 5.5
- 2.0
23: An example of an "Expendable Refrigerant" is
- lithium bromide
- liquid nitrogen
- ammonia
- liquid oxygen
24: Two capacitors are wired in parallel. One capacitor has a value of 15uf. The other has a value of 25uf. What is the total value supplied?
- 15 uf
- 25 uf
- 40 uf
- 20 uf
25: Sublimation occurs when
- gas is formed from a liquid
- ice melts and turns to water
- liquid is formed from a gas
- gas is formed directly from a solid