HVAC NATE HEAT PUMP LATEST 2025
EXAM QUESTIONS AND DETAILED
CORRECT ANSWERS | A+ GRADE
A technician is working on a heat pump with a capacitor
start-capacitor run compressor. On initial startup, the
compressor hums momentarily and the shuts down on
internal overload. What is the problem? Correct Answer
Too great a pressure difference on the compressor.
A step down transformer has a rating of 40 VA. Its primary
voltage is 120V with a secondary voltage of 24V. What is
the maximum current draw of a load connected to this
transformer? Correct Answer 1.7amps
What does a bright red or orange glow from the resistance
element in a duct heater indicate? Correct Answer Flow of
air is insufficient.
What does the outdoor fan do during defrost on a heat
pump and why? Correct Answer The fan stops to minimize
defrost time.
What do bent vanes on a direct drive blower wheel in an
air handler cause? Correct Answer Loss in air flow,
excessive motor wear, and increased noise.
A split system heat pump is using thermostatic expansion
valves. The system performs properly in heating but in
,cooling the compressor pumps down. What could this
mean? Correct Answer The power element of the indoor
expansion valve has lost its charge.
What condition can cause a reduction from design
capacity in a heat pump? Correct Answer Undersized
vapor line.
What is the result of excessive liquid line length or lift?
Correct Answer Flash gas.
What symptom could a technician expect on a heat pump
system in the cooling mode if the check valve is leaking
internally? Correct Answer Flooding of the indoor coil.
Voltage across a closed contact in a 24V control circuit
could indicate what? Correct Answer Pitted or dirty
contacts.
What two checks typically made first on an electronic
control? Correct Answer Proper input voltage and proper
output voltage.
In a low voltage circuit, what does a corroded wire-to-
terminal connection acts like? Correct Answer An
additional resistor.
How should you test the continuity of a fuse? Correct
Answer Power off, fuse removed
, What is the first check made for most electrical
troubleshooting? Correct Answer Voltage check of the
supply line.
The following conditions exist in a circuit that supplies
power to three parallel loads.
One load is resistive
One load is capacitive
One load is inductive
How do you find the total current? Correct Answer The
sum of the currents through each load.
The technician is using an analog multimeter to check a
run capacitor. With the meter set to ohms the needle
swings toward zero and then slowly rises toward infinity.
What does this tell the technician? Correct Answer The
capacitor charges and discharges.
When should a technician test a hermetic compressor for
a permanently open internal overload protector? Correct
Answer While its cool.
What is defined as two or more switch contacts connected
in a circuit, or set of circuits, to control a load? Correct
Answer Control String
EXAM QUESTIONS AND DETAILED
CORRECT ANSWERS | A+ GRADE
A technician is working on a heat pump with a capacitor
start-capacitor run compressor. On initial startup, the
compressor hums momentarily and the shuts down on
internal overload. What is the problem? Correct Answer
Too great a pressure difference on the compressor.
A step down transformer has a rating of 40 VA. Its primary
voltage is 120V with a secondary voltage of 24V. What is
the maximum current draw of a load connected to this
transformer? Correct Answer 1.7amps
What does a bright red or orange glow from the resistance
element in a duct heater indicate? Correct Answer Flow of
air is insufficient.
What does the outdoor fan do during defrost on a heat
pump and why? Correct Answer The fan stops to minimize
defrost time.
What do bent vanes on a direct drive blower wheel in an
air handler cause? Correct Answer Loss in air flow,
excessive motor wear, and increased noise.
A split system heat pump is using thermostatic expansion
valves. The system performs properly in heating but in
,cooling the compressor pumps down. What could this
mean? Correct Answer The power element of the indoor
expansion valve has lost its charge.
What condition can cause a reduction from design
capacity in a heat pump? Correct Answer Undersized
vapor line.
What is the result of excessive liquid line length or lift?
Correct Answer Flash gas.
What symptom could a technician expect on a heat pump
system in the cooling mode if the check valve is leaking
internally? Correct Answer Flooding of the indoor coil.
Voltage across a closed contact in a 24V control circuit
could indicate what? Correct Answer Pitted or dirty
contacts.
What two checks typically made first on an electronic
control? Correct Answer Proper input voltage and proper
output voltage.
In a low voltage circuit, what does a corroded wire-to-
terminal connection acts like? Correct Answer An
additional resistor.
How should you test the continuity of a fuse? Correct
Answer Power off, fuse removed
, What is the first check made for most electrical
troubleshooting? Correct Answer Voltage check of the
supply line.
The following conditions exist in a circuit that supplies
power to three parallel loads.
One load is resistive
One load is capacitive
One load is inductive
How do you find the total current? Correct Answer The
sum of the currents through each load.
The technician is using an analog multimeter to check a
run capacitor. With the meter set to ohms the needle
swings toward zero and then slowly rises toward infinity.
What does this tell the technician? Correct Answer The
capacitor charges and discharges.
When should a technician test a hermetic compressor for
a permanently open internal overload protector? Correct
Answer While its cool.
What is defined as two or more switch contacts connected
in a circuit, or set of circuits, to control a load? Correct
Answer Control String
