Topics: All categories in the pool
1: Dual-pressure relief devices should be installed on
- vessels of 3 cubic feet or more
- vessels of 10 cubic feet or more
- vessels of 3 cubic feet or less
- vessels of 10 cubic feet or less
2: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
- 365 psig
- 255 psig
- 125 psig
- 327 psig
3: What is Trichlorotrifluoromethane?
- R-12
- R-13
- R-113
- R-11
4: What instrument is used to measure very high resistance?
- voltmeter
- ammeter
- meg ohmmeter
- tape measure
5: The ASHRAE Standard 34 requires what type of alarm for equipment rooms using HCFC-123?
- refrigerant sensing
- A group sensing
- phosgene gas sening
- CO Sensing
6: The two basic types of evaporators are
- finned and plate
- flooded and direct expansion
- direct expansion and plate
- prime surface and finned
7: A cross charged power element on an expansion valve would normally be used in what temperature range?
- -40F to 0F
- -100F to -40F
- 0F-38F
- 30F to 50F
8: Increasing superheat will do what to your system?
- Nothing
- Increase liquid flow
- Increase gas flow
- Decrease liquid flow
9: Refrigerant is metered into the evaporator on a large centrifugal chiller thru the
- low side of the system
- high side float assembly
- cap tube
- none of the above
10: If air is present in an absorption chilled water appliance, which of the following will most likely occur?
- The Li-Br solution will become more diluted
- Rust can form
- The Li-Br solution will become more concentrated
- System operating pressure will drop
11: How many flammability classifications are refrigerants in?
- 5
- 2
- 3
- 7
12: Materials used in construction and installation materials used in the manufacture or installation of refrigerating equipment shall be suitable for conveying refrigerant and the refrigerant oils and will not deteriorate in the presence of what?
- Water and soap
- Moisture and air
- Air and dirt
- Oil and water
13: R-11 belongs to Group
- A-2
- B-3
- B-1
- A-1
14: Who approves containers for refrigerants?
- E.P.A
- D.O.T
- D.O.D
- D.O.E
15: A class A3 refrigerant is considered
- toxic and somewhat flammable
- non-toxic and non-flammable
- non-toxic but highly flammable
- toxic and non-flammable
16: Insurance companies shall forward each inspection report of all refrigeration or A/C systems to the Chief of Inspections within
- 14 days
- 30 days
- 1 week
- 2 months
17: What type of fuses must be used on a HVAC system?
- TR Type, Duel Element, Time Delay
- Fast blow
- 10% lower than RLA
- none of the above
18: 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
19: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?
- Low Pressure displacement
- Non-positive displacement
- Positive displacement
- Pressure induced displacement.
20: What is used to check very low pressure?
- Hydrometer
- Manometer
- Hygrometer
- Velometer
21: Mercury was used in thermometers primarily because it
- expands uniformly
- never freezes
- vaporizes at very high temperatures
- was inexpensive
22: What is the typical air conditioning operating pressures for 410A?
- 60 psi suction, 210 psi discharge
- 25 psi suction, 125 psi discharge
- 105 psi suction, 350 psi discharge
- None of the above
23: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
24: A chiller entering and leaving temperature difference is?
- 20 degrees F
- 5 degrees F
- 10 degrees F
- 50 degrees F
25: Which refrigerant class listed below is the most flammable?
- B-2
- A-3
- A-1
- C-3