NATE Heat Pump Exam questions with correct answers
The function of a reversing valve is to provide - ✔✔ANSW✔✔..heating and/or cooling
The relationship between inrush current and holding current of a relay coil is inrush
current is - ✔✔ANSW✔✔..always greater than holding current
The capability of electronic programmable room thermostat to reset the set point early
so that the space temperature reaches a set temperature at a specific time is called -
✔✔ANSW✔✔..computed recovery
When using a double (dual) element time-delay fuse with a 20 amp motor, the
maximum fuse size should be - ✔✔ANSW✔✔..25 amps
According to fire protection codes, fire dampers should be used in any air duct that -
✔✔ANSW✔✔..passes through all walls or partitions of a light commercial installation
When the capacity of a heat pump in heating, measured in Btu's, is the same as the
heat loss of a structure, the system is said to have reached its - ✔✔ANSW✔✔..balance
point
A suction line accumulator should be used in a residential heat pump only when -
✔✔ANSW✔✔..recommended by the manufacturer if long refrigerant lines increase
system charge over recommended maximum charge
The measurement of a heat pumps efficiency is often stated using its "Coefficient of
Performance" or COP. The COP of a heat pump is the heat pumps -
✔✔ANSW✔✔..heat output in watts divided by its total electrical input in watts
The purpose of calculating the heat loss at an outside design temperature is to -
✔✔ANSW✔✔..select the appropriate equipment based on Btu output
The minimum circuit amp listed on a units' data plate is used to determine the -
✔✔ANSW✔✔..max fuse or circuit breaker size.
Heat pumps are particularly sized based on the - ✔✔ANSW✔✔..cooling load
The effective method of reducing sound when AHU is located in a closet is to use -
✔✔ANSW✔✔..vibration isolators
, When wiring a 20 amp FLA motor, the minimum amp fuse or circuit breaker should be -
✔✔ANSW✔✔..25
The typical staging of a two stage HP system uses the deviation of the t-stat setting to
determine - ✔✔ANSW✔✔..when to engage each stage.
The purpose of a sequencer in a HP with an AUX 20 kW electric heater is to -
✔✔ANSW✔✔..energize one or two elements and the blower then energize the other
elements in timed intervals.
In a HP circuit, an open check valve is used to - ✔✔ANSW✔✔..by-pass refrigerant flow
around the metering device.
R-22 vapor line diameters and lengths are typically specified for a vapor pressure drop
that does not exceed - ✔✔ANSW✔✔..6-7 psi or 6 degress F
The primary purpose of using flux when soldering copper or brass parts is to prevent -
✔✔ANSW✔✔..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 - ✔✔ANSW✔✔..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 - ✔✔ANSW✔✔..Curb gasket
When under a deep vacuum, a hermetic refrigeration compressor's motor windings
could be ________ if energized - ✔✔ANSW✔✔..Damaged
In order for an evacuation to be considered complete, a heat pump refrigerant circuit
should be evacuated to a vacuum pressure of - ✔✔ANSW✔✔..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 - ✔✔ANSW✔✔..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 -
✔✔ANSW✔✔..Shorter
The function of a reversing valve is to provide - ✔✔ANSW✔✔..heating and/or cooling
The relationship between inrush current and holding current of a relay coil is inrush
current is - ✔✔ANSW✔✔..always greater than holding current
The capability of electronic programmable room thermostat to reset the set point early
so that the space temperature reaches a set temperature at a specific time is called -
✔✔ANSW✔✔..computed recovery
When using a double (dual) element time-delay fuse with a 20 amp motor, the
maximum fuse size should be - ✔✔ANSW✔✔..25 amps
According to fire protection codes, fire dampers should be used in any air duct that -
✔✔ANSW✔✔..passes through all walls or partitions of a light commercial installation
When the capacity of a heat pump in heating, measured in Btu's, is the same as the
heat loss of a structure, the system is said to have reached its - ✔✔ANSW✔✔..balance
point
A suction line accumulator should be used in a residential heat pump only when -
✔✔ANSW✔✔..recommended by the manufacturer if long refrigerant lines increase
system charge over recommended maximum charge
The measurement of a heat pumps efficiency is often stated using its "Coefficient of
Performance" or COP. The COP of a heat pump is the heat pumps -
✔✔ANSW✔✔..heat output in watts divided by its total electrical input in watts
The purpose of calculating the heat loss at an outside design temperature is to -
✔✔ANSW✔✔..select the appropriate equipment based on Btu output
The minimum circuit amp listed on a units' data plate is used to determine the -
✔✔ANSW✔✔..max fuse or circuit breaker size.
Heat pumps are particularly sized based on the - ✔✔ANSW✔✔..cooling load
The effective method of reducing sound when AHU is located in a closet is to use -
✔✔ANSW✔✔..vibration isolators
, When wiring a 20 amp FLA motor, the minimum amp fuse or circuit breaker should be -
✔✔ANSW✔✔..25
The typical staging of a two stage HP system uses the deviation of the t-stat setting to
determine - ✔✔ANSW✔✔..when to engage each stage.
The purpose of a sequencer in a HP with an AUX 20 kW electric heater is to -
✔✔ANSW✔✔..energize one or two elements and the blower then energize the other
elements in timed intervals.
In a HP circuit, an open check valve is used to - ✔✔ANSW✔✔..by-pass refrigerant flow
around the metering device.
R-22 vapor line diameters and lengths are typically specified for a vapor pressure drop
that does not exceed - ✔✔ANSW✔✔..6-7 psi or 6 degress F
The primary purpose of using flux when soldering copper or brass parts is to prevent -
✔✔ANSW✔✔..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 - ✔✔ANSW✔✔..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 - ✔✔ANSW✔✔..Curb gasket
When under a deep vacuum, a hermetic refrigeration compressor's motor windings
could be ________ if energized - ✔✔ANSW✔✔..Damaged
In order for an evacuation to be considered complete, a heat pump refrigerant circuit
should be evacuated to a vacuum pressure of - ✔✔ANSW✔✔..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 - ✔✔ANSW✔✔..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 -
✔✔ANSW✔✔..Shorter
