EPA Type 3 review questions

Card Set Information

EPA Type 3 review questions
2015-06-28 21:51:05
EPA type3

review questions for type 3
Show Answers:

  1. According to ASHRAE guidelines 1996,what should you do  if the pressure in a system rises from 1 mm to a level above 2.5 mm Hg a standing vacuum test,
    the system should be checked for leaks
  2. with a low-pressure chiller, what must you do after recovering the liquid refrigerant
    recover the vapor refrigerant
  3. EPA reg. require that commercial & industrial process refrigerant be repaired when the leak rate exceeds _____% annually
  4. where would you place a leak detector probe to check for leaks into the water box with the water removed
    the leak detector probe should be first placed in the drain vave to check for leaks
  5. how do you determine when enough vapor has entered the refrigeration system before you charge refrigerant liquid
    when the system temp rises to 36* ,to prevent boiling of the liquid refrigerant ,that could freeze water in the system
  6. when removing oil from a low pressure system, the temp should be 130* because,
    this will boil off the refrigerant out of the oil
  7. hydrostatic test tube or eddy current test is used for what
    x-ray device used to check for cracks and leaks in the metal tubes
  8. R-11 & R-123 low pressure refrigerants removal starts with what
    liquid removal, than switches to vapor removal.
  9. charged low-pressure refrigerant system may be most efficiently leak checked if you do what to the system
    • you can raise the pressure of the refrigerant, taking it out of a vacuum,by covering the chiller with a heated blanket, or circulating hot water.
    • remember low-pressure means it's in a vacuum, therefore the refrigerant won't leak out, the outside air will be sucked in.
  10. why do chillers using R-11 & R-123 require purge units
    these are special purge units  that will purge non-condensibles. the system works in a vacuum.
  11. a typical setting for high-pressure cut-out control on a  recovery unit used for evacuating the refrigerant from a low-pressure chiller is ;
    10 psig
  12. appliances containing more than 50Lbs of refrigerant except for commercial or industrial, be repaired when the leak rate exceeds______of the charge per year
  13. after servicing, why is refrigerant vapor re-introduced to the refrigeration system before refrigerant liquid?
    liquid charged into a deep vacuum will boil and may lower temp. enough to freeze water in the tubes
  14. R-11 at a pressure of 18.1 inches of mercury vacuum has a saturation temp of
  15. recovery after 1993, evacuation low-pressure system to the following level
    25 millimeter of hg absolute
  16. under EPA regulations, which of the following methods can be used for a no-major repair
    warming the refrigerant
  17. which of the following repairs would be considered major repair
    replacement of the condenser, evaporator,compressor, or heat reclaim coil
  18. systems do not need to be evacuated all the way to the prescribed level only when
    leaks in the system make evacuation to the prescribed level unattainable
  19. after reaching the required recovery vacuum on a system, you should do what
    wait a few minutes to see if the pressure rises, indicating refrigerant in the oil
  20. when recovering before 1993, you must evacuate to
    25 inches of hg before making any repairs
  21. the primary purpose of a purge unit on a chiller is to;
    remove  non-condensibles from the system
  22. under what code group of ASHRAE standard 34 does R-123 fall
  23. on a centrifugal system the purge unit takes its suction from  where
    the top of the condensor
  24. refrigeration is added to the centrifugal system through what
    evaporator charging valve