NATE AIR CONDITIONING AND HEAT PUMP STUDY GUIDE
2025/2026 QUESTIONS WITH ANSWERS GRADED A+
✔✔What tool should be used to shorten a capillary tube? - ✔✔A triangular or knife-edge
file
✔✔Which pressure in a TEV is opening pressure? - ✔✔bulb pressure
✔✔What effect does a low refrigerant charge have on reversing valve operations? -
✔✔It increases the chance that the reversing valve will not be able to transfer properly
✔✔When adding a heat pump to an existing fossil-fuel furnace, an installer must do all
of the following except ______. - ✔✔Make sure that the new number of fins per inch of
the new coils equals that of the replaced coils
✔✔What is the purpose of a receiver? - ✔✔It store liquid refrigerant
✔✔What is the typical storage life of modern refrigerants? - ✔✔Modern refrigerants
have an indefinite storage life
✔✔Which of the following should be used to leak-test refrigerant tubing? - ✔✔Dry
Nitrogen
✔✔Of the motors commonly used in HVACR systems, which type has the lowest
starting torque? - ✔✔Shaded-pole motor
✔✔What is the typical phase angle for a split-phase motor? - ✔✔30
✔✔What determines the staging of a two-speed compressor in a heat pump
application? - ✔✔Deviation from setpoint of the thermostat
✔✔The NEC approves a _____ dual-element time-delay fuse as overcurrent protection
for a 20 A motor. - ✔✔60-A
✔✔Voltage supplied to a motor may vary from the rated voltage by _____%. -
✔✔+10%,-10%
✔✔What is one of the most Important reasons for using electronic controls in HVACR
systems? - ✔✔they make decisions based on many inputs
✔✔Hard-start kits are often needed on ______. - ✔✔reciprocating compressors used
with TEVs
, ✔✔A 24-V transformer with a 40-VA rating can operate safely with a current of _____. -
✔✔1.67 A
✔✔Some electromechanical thermostats must be connected to both sides of the
transformer in order to power the _______. - ✔✔display lights on the subbase
✔✔A cooling anticipator in the control circuits is connected in _____ with the _____
switch of the thermostat. - ✔✔parallel, cooling
✔✔According to Ohm's Law, what will happen if the voltage to a heater element is
increased by 10%? - ✔✔The current draw will increase by 10%
✔✔When air flow through an electric heater is not sufficient, the technician will observe
______. - ✔✔Heater elements glowing red or orange
✔✔Which of the following combination of measurements indicates an open heater
element? - ✔✔Voltage to the heater with no current draw through the heater elements
✔✔Which of the following functions occur when a heat pump goes into a defrost cycle?
- ✔✔The auxiliary heat comes on, the outdoor fan stops running, and the reversing
valve switches to the cooling mode
✔✔What internal voltage is likely to be measured in an electronic air cleaner? -
✔✔5,000 V
✔✔What precaution must you take when installing a dual-fuel split system? - ✔✔The
control system must not allow the heat pump and furnace to operate at the same time
during a normal heating cycle
✔✔What problem is likely to occur if a proper trap is not used on the condensate drain
for a draw-through unit? - ✔✔condensate water will not drain properly and will back up
above the primary drain.
✔✔Which of the following issues affects the decision to use a running trap on a
condensate line at the evaporator coil? - ✔✔Running traps do not allow for the proper
drainage of condensate water
✔✔The auxiliary drain line from an overflow pan must _____. - ✔✔Be terminated at
some conspicuous location so that an overflow is readily noticed
✔✔Which of the following statements about a packaged unit installation is true? -
✔✔The pad used to support a package heat pump should not make contact with the
building
2025/2026 QUESTIONS WITH ANSWERS GRADED A+
✔✔What tool should be used to shorten a capillary tube? - ✔✔A triangular or knife-edge
file
✔✔Which pressure in a TEV is opening pressure? - ✔✔bulb pressure
✔✔What effect does a low refrigerant charge have on reversing valve operations? -
✔✔It increases the chance that the reversing valve will not be able to transfer properly
✔✔When adding a heat pump to an existing fossil-fuel furnace, an installer must do all
of the following except ______. - ✔✔Make sure that the new number of fins per inch of
the new coils equals that of the replaced coils
✔✔What is the purpose of a receiver? - ✔✔It store liquid refrigerant
✔✔What is the typical storage life of modern refrigerants? - ✔✔Modern refrigerants
have an indefinite storage life
✔✔Which of the following should be used to leak-test refrigerant tubing? - ✔✔Dry
Nitrogen
✔✔Of the motors commonly used in HVACR systems, which type has the lowest
starting torque? - ✔✔Shaded-pole motor
✔✔What is the typical phase angle for a split-phase motor? - ✔✔30
✔✔What determines the staging of a two-speed compressor in a heat pump
application? - ✔✔Deviation from setpoint of the thermostat
✔✔The NEC approves a _____ dual-element time-delay fuse as overcurrent protection
for a 20 A motor. - ✔✔60-A
✔✔Voltage supplied to a motor may vary from the rated voltage by _____%. -
✔✔+10%,-10%
✔✔What is one of the most Important reasons for using electronic controls in HVACR
systems? - ✔✔they make decisions based on many inputs
✔✔Hard-start kits are often needed on ______. - ✔✔reciprocating compressors used
with TEVs
, ✔✔A 24-V transformer with a 40-VA rating can operate safely with a current of _____. -
✔✔1.67 A
✔✔Some electromechanical thermostats must be connected to both sides of the
transformer in order to power the _______. - ✔✔display lights on the subbase
✔✔A cooling anticipator in the control circuits is connected in _____ with the _____
switch of the thermostat. - ✔✔parallel, cooling
✔✔According to Ohm's Law, what will happen if the voltage to a heater element is
increased by 10%? - ✔✔The current draw will increase by 10%
✔✔When air flow through an electric heater is not sufficient, the technician will observe
______. - ✔✔Heater elements glowing red or orange
✔✔Which of the following combination of measurements indicates an open heater
element? - ✔✔Voltage to the heater with no current draw through the heater elements
✔✔Which of the following functions occur when a heat pump goes into a defrost cycle?
- ✔✔The auxiliary heat comes on, the outdoor fan stops running, and the reversing
valve switches to the cooling mode
✔✔What internal voltage is likely to be measured in an electronic air cleaner? -
✔✔5,000 V
✔✔What precaution must you take when installing a dual-fuel split system? - ✔✔The
control system must not allow the heat pump and furnace to operate at the same time
during a normal heating cycle
✔✔What problem is likely to occur if a proper trap is not used on the condensate drain
for a draw-through unit? - ✔✔condensate water will not drain properly and will back up
above the primary drain.
✔✔Which of the following issues affects the decision to use a running trap on a
condensate line at the evaporator coil? - ✔✔Running traps do not allow for the proper
drainage of condensate water
✔✔The auxiliary drain line from an overflow pan must _____. - ✔✔Be terminated at
some conspicuous location so that an overflow is readily noticed
✔✔Which of the following statements about a packaged unit installation is true? -
✔✔The pad used to support a package heat pump should not make contact with the
building
