Topics: All categories in the pool
1: Which oil is hydoscopic?
- animal
- mineral
- SW30
- polyolester
2: Which refrigerant class listed below is the most flammable?
- A3
- B2
- A2
- C3
3: Mercury was used in thermometers primarily because it
- was inexpensive
- never freezes
- vaporizes at very high temperatures
- expands uniformly
4: Machinery rooms must be vented to ______?
- basement
- neutralizing tank
- unoccupied spaces
- outdoors
5: What measures gas pressure?
- Hydrometer
- Manometer
- Barometer
- Hygrometer
6: How many flammability classifications are refrigerants in?
- 7
- 2
- 3
- 5
7: Which of the following is an example of an azeotropic refrigerant?
- R-134A
- R-500
- R-410A
- R-404A
8: According to ASHRAE Standard-15 9.8 Positive Displacement Compressor Protection, the pressure-relief device discharge into
- the low-pressure side of the system
- the high side of the system
- the liquid receiver
- both a and c are correct
9: How much clearance do you need around the perimeter of electrical panels?
- 24"
- 12"
- 36"
- 18"
10: What refrigerant were phased out in 2004?
- R-22
- R-12
- R-134a
- R-11
11: The dial of a pressure gauge, when installed on the high side of a system be graduated 1.2 times the designed pressure.
- True
- False
12: What will occur if the strong solution in an absorption chiller becomes too strong?
- The machine will stop cooling and the solution will evaporate.
- The machine will cool excessively as the solution evaporates
- The machine will cool excessively as the solution crystallizes.
- The machine will stop cooling and solution will crystallize
13: Sensible heat is the heat added to a substance to
- cause evaporation
- raise its temperature
- change its state
- freeze it
14: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
- 25%
- 4%
- 1%
- 2%
15: What is a megaohm meter?
- An electric meter used by electricians to test large 3-phase blower motors for the correct rotation
- An electric meter that measures very high resistance values by sending a high DC voltage signal into the object being tested
- Is an electric meter that measures extremely low resistance valves by sending high DC voltage signal into the object being tested.
- An electric meter that measures very high resistance values by sending a low voltage AC signal into the object being tested
16: In a system designed for sub-zero ambient temperatures, what must be added?
- Infrared dye for leak identification
- Nitrogen
- Booster compressor
- Low-ambient kit
17: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
- 99%
- 75%
- 90%
- 80%
18: A direct system
- is a self-contained complete factory made and tested system
- is one which encloses a separate body of evaporative refrigerant
- is on where brine is cooled & circulated to the space refrigerated
- is where the refrigerant comes in contact with the space refrigerated
19: What chemical in the refrigerant set off the leak detection alarm?
- Fluorine
- Chlorine
- Both A and B
- none of the above
20: Which refrigerant replaced R-12?
- R-407A
- R-410A
- R-134A
- R-22
21: Give an example of a secondary coolant?
- R-718
- R-717
- R-12
- R-410A
22: Heat transferred by conduction from one body to another is done
- via solids
- via liquids
- via radiation
- via heat rays
23: Evaporators within 18" of a heating coil must be equipped with a
- pressure relief device
- low limit control
- zone valve
- high limit control
24: The absorber shell contains the
- condenser and the generator
- condenser and the absorber
- condenser, the evaporator, and the generator
- evaporator and the absorber
25: Which of the following is not an air velocity meter?
- Anemometer
- Hydrometer
- Anemotherm
- Velometer