NATE heat pump Exam and Answers
R-22 vapor line diameters and lengths are typically specified for a vapor pressure drop that
does not exceed - ✔✔6-7 psi or 6 degress F
The primary purpose of using flux when soldering copper or brass parts is to prevent -
✔✔Oxidation
The water that results from a defrost cycle of an air to air heat pump (runoff) must drain off and
away from the outdoor coil to prevent - ✔✔Excessive ice build up
The component used to reduce sound transmission and prevent water leaks of a packaged heat
pump installed on a roof is the - ✔✔Curb gasket
When under a deep vacuum, a hermetic refrigeration compressor's motor windings could be
________ if energized - ✔✔Damaged
In order for an evacuation to be considered complete, a heat pump refrigerant circuit should be
evacuated to a vacuum pressure of - ✔✔500 microns or below
A system is supplied from the factory with charge for a 15 foot line set. The data plate shows
the required system charge to be 5 pounds 10 ounces. The line set uses a 3/8 inch liquid line
and is 25 feet long. The manufacturer's instruction sheet specifies 0.6 ounces of refrigerant to
be added for each added foot of refrigerant line length so the total refrigerant charge for the
system would be - ✔✔6 lbs(25-15=10 10x0.6=6oz 6oz+5lbs 10oz= 5lbs 16oz the equilvalent of
6lbs)
Drive slips are typically installed on the __________ sides of rectangular ducts - ✔✔Shorter
To properly set a heat anticipator it is necessary to check the - ✔✔heating control circuit
amperage draw
, A heat pump operating in normal ice free conditions maintains a certain temperature
difference between the outdoor coil temperature and the surrounding outdoor ambient. This
temperature difference is referred to as - ✔✔Coil TD (temperature difference)
The smallest refrigerant leak that an electronic leak detector should be capable of sensing is -
✔✔0.05 oz. per year
When checking the pressures in an operating system with a manifold gauge set, refrigerant oil
in a hose will have ___ ______ on the gauge reading - ✔✔No effect
At sea level, a gauge pressure of 35 psig is equal to an absolute pressure of - ✔✔49.7 psia
A technician measures the return air temperature of a 100,000 Btu output furnace to be 65°F
and the supply side air temperature is 135°F. The CFM would be - ✔✔1323 (TD= 135-
65=70➡️100,000/TDx1.08 ➡️100,000/75.6=1323)
A residential supply diffuser that is noisy because of a loose vane is best serviced by -
✔✔Replacing the diffuser
When performing preventive maintenance on a heat pump the technician should check the
outdoor fan to be certain that the fan - ✔✔runs freely with no binding
What is the effect of 170 volts supplied to a 208/230 volt compressor would cause a current -
✔✔increase and the motor may trip on overload
On a service call for a cooling problem with a heat pump, your inspections find a liquid line that
has condensation on it. The most likely cause would be the - ✔✔liquid line is restricted
R-22 vapor line diameters and lengths are typically specified for a vapor pressure drop that
does not exceed - ✔✔6-7 psi or 6 degress F
The primary purpose of using flux when soldering copper or brass parts is to prevent -
✔✔Oxidation
The water that results from a defrost cycle of an air to air heat pump (runoff) must drain off and
away from the outdoor coil to prevent - ✔✔Excessive ice build up
The component used to reduce sound transmission and prevent water leaks of a packaged heat
pump installed on a roof is the - ✔✔Curb gasket
When under a deep vacuum, a hermetic refrigeration compressor's motor windings could be
________ if energized - ✔✔Damaged
In order for an evacuation to be considered complete, a heat pump refrigerant circuit should be
evacuated to a vacuum pressure of - ✔✔500 microns or below
A system is supplied from the factory with charge for a 15 foot line set. The data plate shows
the required system charge to be 5 pounds 10 ounces. The line set uses a 3/8 inch liquid line
and is 25 feet long. The manufacturer's instruction sheet specifies 0.6 ounces of refrigerant to
be added for each added foot of refrigerant line length so the total refrigerant charge for the
system would be - ✔✔6 lbs(25-15=10 10x0.6=6oz 6oz+5lbs 10oz= 5lbs 16oz the equilvalent of
6lbs)
Drive slips are typically installed on the __________ sides of rectangular ducts - ✔✔Shorter
To properly set a heat anticipator it is necessary to check the - ✔✔heating control circuit
amperage draw
, A heat pump operating in normal ice free conditions maintains a certain temperature
difference between the outdoor coil temperature and the surrounding outdoor ambient. This
temperature difference is referred to as - ✔✔Coil TD (temperature difference)
The smallest refrigerant leak that an electronic leak detector should be capable of sensing is -
✔✔0.05 oz. per year
When checking the pressures in an operating system with a manifold gauge set, refrigerant oil
in a hose will have ___ ______ on the gauge reading - ✔✔No effect
At sea level, a gauge pressure of 35 psig is equal to an absolute pressure of - ✔✔49.7 psia
A technician measures the return air temperature of a 100,000 Btu output furnace to be 65°F
and the supply side air temperature is 135°F. The CFM would be - ✔✔1323 (TD= 135-
65=70➡️100,000/TDx1.08 ➡️100,000/75.6=1323)
A residential supply diffuser that is noisy because of a loose vane is best serviced by -
✔✔Replacing the diffuser
When performing preventive maintenance on a heat pump the technician should check the
outdoor fan to be certain that the fan - ✔✔runs freely with no binding
What is the effect of 170 volts supplied to a 208/230 volt compressor would cause a current -
✔✔increase and the motor may trip on overload
On a service call for a cooling problem with a heat pump, your inspections find a liquid line that
has condensation on it. The most likely cause would be the - ✔✔liquid line is restricted
