Topics: All categories in the pool
1: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- 1.7
- 1.2
- .8
- .1
2: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
- phosgene gas sening
- A group sensing
- CO Sensing
- refrigerant sensing
3: Class A refrigerants are considered
- flammable
- toxic
- non-toxic
- non-flammable
4: The actual expansion curve of compression follows most nearly which one of the following curves?
- Pressure Temperature
- Isothermal
- Volume Temperature
- Adiabatic
5: What is the purpose of a surge capacitor on a contactor?
- to keep the contactor pulled in
- to balance the sine waves
- to protect low voltage equipment
- to provide smoother start/stops
6: What must be done if refrigeration lines pass through a concrete floor?
- insulated
- installed through a pipe casing
- leak checked
- moisture barrier
7: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 66
- 22
- 25
- 50
8: Capacity control on a centrifugal compressor is accomplished by the
- post-rotational guide vanes
- slide vanes
- check valves
- pre-rotational guide vanes
9: Liquid line filter-driers on a 410A system must be rated for no less than
- 1000 psig
- 400 psig
- 600 psig
- 200 psig
10: Large mercantile occupancy is
- a premise or that portion of a premise where more than 1500 persons congregate on levels above or below street level to purchase personal merchandise
- a premise of that portion of a premise where more than 50 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise of that portion of a premise where more than 100 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise or that portion of a premise where more than 200 persons congregate on levels above or below street level to purchase personal merchandise
11: A device used to measure small pressure differences is the
- manometer
- phsycometirc
- anemometer
- pyrometer
12: When testing systems using non-positive displacement compressors, the entire system shall be considered for test purposes as the low side.
- True
- False
13: Halogen refrigerants are corrosive to which type of metal?
- copper
- magnesium
- black iron
- stainless steel
14: What is a high-side float?
- Located in the liquid line entering the evaporator, so when the refrigerant level is higher in the liquid line than the evaporator, the float rises to allow more refrigerant flow into the evaporator
- An electronic-type metering device that contains a float assembly within the device which can accurately meter refrigerant into the evaporator as the load varies
- Located in the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the low side of the chiller
- Located in the liquid line entering the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the high side of the chiller
15: Which refrigerant replaced R-12?
- R-410A
- R-134A
- R-22
- R-407A
16: The high side float assembly meters refrigerant into the evaporator through the
- lower chamber of the low side
- upper chamber of the high side
- lower chamber of the high side
- upper chamber of the low side
17: What refrigerant has zero ozone depletion
- HFC
- CFC
- HCFC
- None of the above
18: Which of the following controllers would you expect to be most sensitive to temperature changes?
- aquastat
- line voltage t-stat
- immersion controller
- low voltage t-stat
19: An electronic bridge circuit is basically a
- 24 volt control circuit
- suspension
- high voltage circuit
- Wheatstone
20: 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
21: Pressure vessels with an internal volume of 10 cubic feet or more
- shall use rupture discs or duel pressure relief valves
- shall use pressure relief devices
- shall use pressure relief devices or fusible plugs
- shall use fusible plugs
22: A VRF system is a direct system
- true
- false
23: There can be no airflow from an occupied space through a machine room unless what?
- System is high velocity
- System is ducted and sealed
- Duct is not located in the ceiling
- None of the above.
24: A machine room with a refrigerant system using ammonia shall
- be provided with a continuously operated ventilation system
- be considered a non-hazardous location in accordance with National Electrical code
- have no flame producing apparatus permanently installed and operated
- All of the above
25: How many square inches per square foot?
- 64
- 24
- 144
- 98