Topics: All categories in the pool
1: Can ammonia be used on domestic system?
- yes, for systems under 10 tons
- yes
- no, unless there is proper ventilation system installed
- no
2: The best way to detect ammonia in brine is
- potassium of line
- CO2 gas
- carbonation of soda
- nessler regaent
3: Refrigeration piping before being buried shall be
- leak tested
- encased in pipe duct
- pressure tested
- All of the above
4: What is the refrigerant chlorodifluoromethane?
- R-12
- R-22
- R-134a
- R-123
5: copper and its alloys shall not be used in contact with _____ except as a component of bronze alloys for bearing or other non-refrigerant containing uses.
- Lithium bromide
- HCFC-123
- CFC-11
- ammonia
6: Liquid refrigerant flashing, or turning to vapor, in the liquid line may be due to
- liquid line that is too small
- shortage of refrigerant
- liquid line that had too high vertical lift
- All of the above
7: When is the space above a drop ceiling calculated as space for refrigerant limit quantities?
- When there are sprinklers above
- When its white
- When there is a space 6' or more above it
- When it's used as part of a supply or return air system
8: What is the purpose of suction/discharge traps?
- to ensure proper oil return to the compressor
- to keep oil inside the evaporator for proper oil return to the compressor
- to keep oil inside of the accumulator for proper return to the compressor
- all of the above
9: How many square inches per square foot?
- 144
- 64
- 98
- 24
10: What refrigerant has zero ozone depletion
- HFC
- CFC
- HCFC
- None of the above
11: In an air conditioning plant which an indirect low side, water is used inside of bring: the proper sequence of operating the plan is
- reset the expansion valve
- start the comrpessor
- start the fan and circulating pump
- reset the safety valve
12: Which refrigerant was still able to be vented to the atmosphere after July 1, 1992?
- R-113
- R-11
- R-22
- R-12
13: What will occur if the strong solution in an absorption chiller becomes too strong?
- The machine will cool excessively as the solution crystallizes.
- The machine will stop cooling and the solution will evaporate.
- The machine will cool excessively as the solution evaporates
- The machine will stop cooling and solution will crystallize
14: The location of a thermal bulb of a TXV affects
- the amount of liquid refrigerant in the evaporator
- the amount of liquid in the condenser.
- the amount of liquid returning to the compressor
- subcooling
15: Electricity involves the movement of electrons in atoms
- True
- False
16: Secondary refrigerants are usually
- water or brine
- alcohol
- Prestone anti-freeze
- expensive
17: Total heat of a substance is considered
- specific heat
- sensible heat
- empathetical
- enthalpy
18: What refrigerant doesn't have to be classified?
- R-717
- R-718
- R-422A
- R-134A
19: What is Trichlorotrifluoromethane?
- R-113
- R-12
- R-13
- R-11
20: When an electronic bridge is in balance the bridge output will be
- 15 volts
- 0 volts
- 1 volt
- .01 volts
21: Liquid line filter-driers on a 410A system must be rated for no less than
- 1000 psig
- 600 psig
- 400 psig
- 200 psig
22: The principle used in continuous type absorption systems is
- Charles's Law
- Dalton's Law
- Ohm's Law
- Boyle's Law
23: R-11 belongs to Group
- A-2
- A-1
- B-3
- B-1
24: 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
- run voltage
- boost voltage
- pick-up voltage
25: Direct systems using Group II refrigerants
- shall be installed per instruction of the AHJ
- shall be installed in Class T machinery rooms
- shall be allowed to be used for human comfort.
- shall not be used for air condition for human comfort