RATED A+
✔✔Whenever dry nitrogen from a portable cylinder is used in service and installation
practice,the
most important safety consideration is that.
A.the regulator has a new set of gauges
B.the gauges are clean
C.a relief valve is inserted in the downstream line from the pressure regulator
D.no refrigerant lines can leak - ✔✔C
✔✔Personal protective equipment(gloves,safety glasses,safety shoes,etc.)must be
wom when.
A.reporting for work
B.handling and filling refrigerant cylinders
C.climbing ladders
D.lifting - ✔✔B
✔✔__is a chlorine-free refrigerant.
A.HFC-134a
B.CFC-2
C.HCFC-22
D.HCFC-124 - ✔✔A
✔✔When leak checking a unit that has lost a complete charge,__is/are the gas(es)that
would
cause the least damage to the environment.
A.dry nitrogen and R-22
B.compressed air and R-12
C.dry nitrogen
D.dry nitrogen and R-12 - ✔✔C
✔✔When evacuating a system,the use of a large vacuum pump could cause_to freeze.
A.trapped oil
B.trapped refrigerant
C.trapped water
D.valves - ✔✔C
✔✔In order to verify the allowable refrigeration system test pressure,check
A.with the equipment owner or representative
B.refrigerant pressure tables
C.the design pressure on the equipment nameplate
D.with the local utility company - ✔✔C
,✔✔To determine the safe pressure for leak testing a system,a technician should use_.
A.low-side test-pressure data-plate value
B.discharge operating pressure
C.ambient+300temperature/pressure value
D.ambient at standby condition - ✔✔A
✔✔__is a gas that helps form a protective shield around the Earth.
A.Methane
B.Radon
C.Stratospheric ozone
D.Carbon dioxide - ✔✔C
✔✔Refrigerant entering the compressor of a refrigeration system is a.
A.liquid
B.subcooled liquid
C.subcooled vapor
D.superheated vapor - ✔✔D
✔✔The state of refrigerant leaving the condenser of a refrigeration system is.
A.low-pressure liquid
B.low-pressure vapor
C.high-pressure liquid
D.high-pressure vapor - ✔✔C
✔✔Failure of a system to hold a vacuum at the end of the evacuation process indicates
that_.
A.the system is ready to be charged
B.the system has been adequately evacuated
C.a leak in the system exists
D.the feed device is plugged - ✔✔C
✔✔A system is said to be dehydrated when.
A.the vacuum indicator shows that the required finished vacuum has been reached and
held
B.the vacuum pump has run for at least 12 hours
C.the manifold suction gauge has held 30 in.Hg vacuum for 2 hours
D.you are ready to leave for the day - ✔✔A
✔✔__have the highest ozone depletion potential(ODP).
A.HCFCS
B.HFCS
C.CFCS
D.Mineral oils - ✔✔C
, ✔✔When__is found in the upper stratosphere,it indicates that the ozone layer is being
destroyed.
A.carbon monoxide
B.nitrous oxide
C.trioxide
D.chlorine monoxide - ✔✔D
✔✔Of the following refrigerants,__has the lowest ODP.
A.R-22
B.R-123
C.R-134a
D.R-502 - ✔✔C
✔✔__are an effect of stratosphere ozone depletion on the environment.
A.Volcanic eruptions
B.Chlorine compounds
C.Visible light distortions
D.Reduced crop yields - ✔✔D
✔✔The recovery of refrigerants is necessary to.
A.sell appliances
B.stop Legionnaires'disease from spreading
C.give refrigerants low ODP additives
D.provide adequate supplies for service after production bans are in effect - ✔✔D
✔✔To stop damage to the stratospheric ozone layer,the United States is.
A./using ground level ozone to rebuild the ozone layer
B.stopping the production and regulating the use of CFCs
C.moving away from CFCs and toward Halons TM
D.stopping the production of HFC and HCFC refrigerants - ✔✔B
✔✔Equipment covered by EPA regulations includes.
A.only refrigerators and freezers
B.all air conditioning and refrigeration equipment containing and using CFC refrigerants
C.all air conditioning and refrigeration equipment containing and using CFC and HCFC
refrigerants
D.only commercial air conditioning and refrigeration equipment - ✔✔C
✔✔he EPA classifies-as a"low-pressure refrigerant."
A.R-134a
B.R-123
C.R-22
D.R-500 - ✔✔B