QUESTIONS AND ANSWERS SURE A+
✔✔A rupture disc on a recovery vessel for low pressure refrigerants relieves at:
________.
a) 5 psig
b) 10 psig
c) 15 psig
d) 20 psig - ✔✔c) 15 psig
✔✔The primary water source for a recovery unit condensing coil is: _________.
a) chilled water
b) condenser water
c) local municipal water supply
d) de-ionized water - ✔✔c) local municipal water supply
✔✔Which of the following repairs that would ALWAYS be considered "major" under
EPA's regulations?
a) replacement of an evaporator coil
b) replacement of a filter-drier
,c) replacement of a switch
d) replacement of a purge unit - ✔✔a) replacement of an evaporator coil
✔✔According to the EPA, there is approximately ________ of refrigerant vapor left in an
average 350 ton R-11 chiller at 0 psig pressure once all the R-11 liquid has been
removed.
a) None.
b) 10 pounds.
c) 20 pounds.
d) 100 pounds. - ✔✔d) 100 pounds.
✔✔A centrifugal chiller's rupture disk is connected to the chiller's: ________.
a) condenser
b) evaporator
c) liquid line
d) economizer - ✔✔b) evaporator
✔✔When charging a chiller, refrigerant vapor is introduced into the system before
charging with liquid. That is because: ___________.
a) vapor charging increases pressure slowly, preventing failure of the rupture disc
b) vapor charging is faster than liquid charging
c) liquid charging is more difficult to control than vapor charging
d) liquid charged into a deep vacuum will cause the refrigerant to boil and lower
temperatures enough to freeze the water in the tubes - ✔✔d) liquid charged into a deep
vacuum will cause the refrigerant to boil and lower temperatures enough to freeze the
water in the tubes
✔✔To determine how much vapor to charge into an evacuated chiller, you should
charge with vapor until: __________.
a) the system pressure corresponds to a refrigerant saturation temperature of 36
degrees F
b) the recovery unit liquid level drops
c) you have charged with vapor for 15 minutes
d) the recovery unit pressure drops - ✔✔a) the system pressure corresponds to a
refrigerant saturation temperature of 36 degrees F
✔✔When there is excessive moisture collecting in the purge unit of a low pressure
refrigeration system, this indicates that: _________.
a) the system was charged with contaminated refrigerant
b) the condenser or chiller barrel tubes are leaking
, c) the purge unit is not operating properly
d) the purge unit needs adjustment - ✔✔b) the condenser or chiller barrel tubes are
leaking
✔✔During chiller evacuation, water is circulated to: _________.
a) speed up the recovery process
b) prevent loss of refrigerant to the atmosphere
c) prevent freezing of the water
d) maintain constant refrigerant pressure - ✔✔c) prevent freezing of the water
✔✔A system does not have to be evacuated all the way to the required level when:
__________.
a) the repair is major
b) the repair is followed by an evacuation of the appliance to the environment
c) the appliance is being disposed of
d) leaks in the appliance make evacuation to the prescribed level unattainable - ✔✔d)
leaks in the appliance make evacuation to the prescribed level unattainable
✔✔What is meant by the term "high efficiency purge unit"?
a) Those purge units which discharge a high percentage of refrigerant with the air which
they remove.
b) Those purge units which discharge a low percentage of refrigerant with the air which
they remove.
c) Those purge units which draw very little electrical power.
d) None of the above. - ✔✔b) Those purge units which discharge a low percentage of
refrigerant with the air which they remove.
✔✔The maximum test pressure for leak testing a low pressure centrifugal is: ________.
a) 0 psig
b) 10 psig
c) 25 psig
d) 50 psig - ✔✔b) 10 psig
✔✔When recharging a refrigeration system with R-11, what vapor pressure is
necessary in the shells before charging with liquid?
a) 21.1 inches of Hg vacuum
b) 19.7 inches of Hg vacuum
c) 18.1 inches of Hg vacuum
d) 16.9 inches of Hg vacuum - ✔✔d) 16.9 inches of Hg vacuum