NATE AC Service Certification exam with correct answers
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A |system |is |supplied |from |the |factory |with |charge |of |5 |pounds |10 |ounces |for |a |15 |foot |line |
set. |The |line |set |is |25 |feet |long. |The |manufacturer's |instruction |sheet |specifies |0.6 |ounces |of |
refrigeration |to |be |added |for |each |added |foot |of |refrigerant |line |set |length. |What |is |the |total |
refrigerant |charge |for |the |system?
A. |6 |ounces
B. |5 |pounds
C. |5 |pounds |10 |ounces
D. |6 |pounds |- |correct |answer |D. |6 |pounds |
15ft |- |25ft |= |10ft |x |.6 |= |6 |ounces
5 |pounds |+ |10 |ounces |+ |6 |ounces
5 |pounds |+ |16 |ounces |= |6 |pounds
The |purpose |of |using |flux |when |soldering |is |to:
A. |anneal |the |surface.
B. |give |better |heat |flow.
C. |reduce |oxidation.
D. |pre-seal |the |oxidation. |- |correct |answer |C. |reduce |oxidation.
Outdoor |condensing |units |that |are |installed |in |areas |where |flooding |is |possible |must:
A. |be |mounted |above |flood |level.
B. |utilize |NEMA |1 |enclosures.
C. |be |mounted |under |an |overhanging |eave.
,D. |use |water |resistant |components. |- |correct |answer |A. |be |mounted |above |flood |level.
The |component |used |to |reduce |sound |transmission |and |prevent |water |leaks |on |a |rooftop |air |
conditioner |packaged |unit |installation |is |the:
A. |curb |gasket.
B. |silicone |caulk.
C. |roof |flashing.
D. |roofing |tar. |- |correct |answer |A. |curb |gasket.
Return |air |leakage |in |a |hot |attic |will:
A. |Increase |capacity
B. |Decrease |capacity
C. |Increase |airflow
D. |Decrease |airflow |- |correct |answer |B. |Decrease |capacity
An |air |conditioner |refrigerant |circuit |should |be |evacuated |to |a |minimum |of:
A. |0 |microns.
B. |200 |microns.
C. |500 |microns.
D. |1200 |microns. |- |correct |answer |C. |500 |microns.
Which |of |the |following |substances |could |create |an |extremely |dangerous |condition |if |used |to |
check |refrigeration |system |for |leaks?
A. |R-22
B. |Nitrogen
, C. |Oxygen
D. |Carbon |Dioxide |- |correct |answer |D. |Carbon |Dioxide
The |subcooling |method |for |checking |charge |is |generally |used |on |air |conditioners |with |what |
type |of |metering?
A. |Only |externally |equalized |thermostatic |expansion |valves
B. |Any |thermostatic |expansion |valve
C. |Piston |type
D. |Any |fixed |metering |device |- |correct |answer |B. |Any |thermostatic |expansion |valve
Supply |ducts |running |through |unconditioned |space |should |be |insulated |and |have:
A. |equal |friction.
B. |excessive |air |velocity.
C. |a |vapor |barrier.
D. |a |transition |backing. |- |correct |answer |C. |a |vapor |barrier.
An |important |consideration |when |installing |a |motorized |economizer |is |to |check |to |be |certain |
that:
A. |the |vanes |are |set |for |a |maximum |10% |outdoor |air.
B. |the |vanes |open |on |any |call |for |cooling.
C. |the |vanes |operate |without |binding.
D. |the |vanes |are |permanently |set |at |50%. |- |correct |answer |C. |the |vanes |operate |without |
binding.
On |a |3 |ton |unit |installation, |the |measure |airflow |equals |1550 |CFM. |What |does |this |indicate?
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A |system |is |supplied |from |the |factory |with |charge |of |5 |pounds |10 |ounces |for |a |15 |foot |line |
set. |The |line |set |is |25 |feet |long. |The |manufacturer's |instruction |sheet |specifies |0.6 |ounces |of |
refrigeration |to |be |added |for |each |added |foot |of |refrigerant |line |set |length. |What |is |the |total |
refrigerant |charge |for |the |system?
A. |6 |ounces
B. |5 |pounds
C. |5 |pounds |10 |ounces
D. |6 |pounds |- |correct |answer |D. |6 |pounds |
15ft |- |25ft |= |10ft |x |.6 |= |6 |ounces
5 |pounds |+ |10 |ounces |+ |6 |ounces
5 |pounds |+ |16 |ounces |= |6 |pounds
The |purpose |of |using |flux |when |soldering |is |to:
A. |anneal |the |surface.
B. |give |better |heat |flow.
C. |reduce |oxidation.
D. |pre-seal |the |oxidation. |- |correct |answer |C. |reduce |oxidation.
Outdoor |condensing |units |that |are |installed |in |areas |where |flooding |is |possible |must:
A. |be |mounted |above |flood |level.
B. |utilize |NEMA |1 |enclosures.
C. |be |mounted |under |an |overhanging |eave.
,D. |use |water |resistant |components. |- |correct |answer |A. |be |mounted |above |flood |level.
The |component |used |to |reduce |sound |transmission |and |prevent |water |leaks |on |a |rooftop |air |
conditioner |packaged |unit |installation |is |the:
A. |curb |gasket.
B. |silicone |caulk.
C. |roof |flashing.
D. |roofing |tar. |- |correct |answer |A. |curb |gasket.
Return |air |leakage |in |a |hot |attic |will:
A. |Increase |capacity
B. |Decrease |capacity
C. |Increase |airflow
D. |Decrease |airflow |- |correct |answer |B. |Decrease |capacity
An |air |conditioner |refrigerant |circuit |should |be |evacuated |to |a |minimum |of:
A. |0 |microns.
B. |200 |microns.
C. |500 |microns.
D. |1200 |microns. |- |correct |answer |C. |500 |microns.
Which |of |the |following |substances |could |create |an |extremely |dangerous |condition |if |used |to |
check |refrigeration |system |for |leaks?
A. |R-22
B. |Nitrogen
, C. |Oxygen
D. |Carbon |Dioxide |- |correct |answer |D. |Carbon |Dioxide
The |subcooling |method |for |checking |charge |is |generally |used |on |air |conditioners |with |what |
type |of |metering?
A. |Only |externally |equalized |thermostatic |expansion |valves
B. |Any |thermostatic |expansion |valve
C. |Piston |type
D. |Any |fixed |metering |device |- |correct |answer |B. |Any |thermostatic |expansion |valve
Supply |ducts |running |through |unconditioned |space |should |be |insulated |and |have:
A. |equal |friction.
B. |excessive |air |velocity.
C. |a |vapor |barrier.
D. |a |transition |backing. |- |correct |answer |C. |a |vapor |barrier.
An |important |consideration |when |installing |a |motorized |economizer |is |to |check |to |be |certain |
that:
A. |the |vanes |are |set |for |a |maximum |10% |outdoor |air.
B. |the |vanes |open |on |any |call |for |cooling.
C. |the |vanes |operate |without |binding.
D. |the |vanes |are |permanently |set |at |50%. |- |correct |answer |C. |the |vanes |operate |without |
binding.
On |a |3 |ton |unit |installation, |the |measure |airflow |equals |1550 |CFM. |What |does |this |indicate?
