Answers|Accurate
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