CORRECT ANSWERS (VERIFIED
ANSWERS) |ALREADY GRADED
• On low pressure chillers, moisture typically enters the refrigerant system
through *correct answer*air leaks from areas with gaskets or fittings
• The maximum test pressure for leak testing a low pressure centrifugal is:
*correct answer*10 psig
• Leak test and repair the chiller to reduce refrigerant loss from a pruge unit
on CFC-11 chiller *correct answer*...
• A hydrostatic tube test kit is used to: *correct answer*determine if a tube
leaks
• Commercial and industrial process refrigeration systems must be repaired
when the leak rate exceeds of the charge per year. *correct answer*35%
• Refrigerant recovery typically start with liquid recovery it is faster.
*correctanswer*...
• A rupture disc on a recovery vessel for a low pressure refrigerants relieves
at: *correct answer*15 psig
• According to ASHRAE Guideline 3-1996, if the pressure in a system rises
from 1 mm Hg to a level above during a standing vacuum test, the system
should be checked for leaks. *correct answer*2.5 mm Hg
• The primary water source for a recovery unit condensing coil is .
*correct answer*local municipal water supply
• When recharging a refrigeration system with R-11, what vaporpressure is
necessary in the shells before changing with liquid? *correct answer*16.9"Hg
vacuum
, • After recovering the liquid refrigerant you must: *correct answer*recover
the vapor refrigerant
• According to the EPA there is approximately refrigerant vapor left in
an average 350 ton R-11 chiller at 0 psig pressure once all the R-11 liquidhas
been removed. *correct answer*100 pounds
• Charging refrigerant liquid into a refrigeration system when it is under a
29inch Hg vacuum can cause the: *correct answer*system water to freeze
• A system does not have to be evacuated all the way to the required level
when: *correct answer*leaks in the appliance make evacuation to the
prescribed level unattainable
• Which of the foloowing repairs would ALWAYS be considered "major"
under EPA's *correct answer*replacement of evaporator coil
• Under EPA's regulation's is used to pressurize a low pressurechiller for the
purpose of opening the system for a non major repair?
*correct answer*warming the refrigerant
• If you are using a recovery machine manufactored AFTER 11-15-93 you
must evacuate an low pressure appliance to before making a major repair.
*correct answer*25 mm of Hg absolute
• After reaching the required recovery vacuum on a chiller, you should
*correct answer*Wait for at least a few minutes to see if the system pressure
rises, indicating that there is till refrigerant in a liquid form or inthe oil
• The pressure corresponding to 32 F for R-123 *correct answer*20 inches
of HG vacuum
• When evacuating a system the use of too large a vacuum pump cancause?
*correct answer*trapped water to freeze
• Refrigerant-11 at a pressure of 17 inches HG vacuum has a saturation
temperature of: *correct answer*35F