NATE AC Service Certification Exam Latest 2026 Actual
Exam| Complete 100 Real Exam Questions and Correct
Verified Answers/ Graded A+ (New!!)
1. Which of the following substances could create an
extremely dangerous condition if used to check a refrigeration
system for leaks?
A. R-22
B. Nitrogen
C. Oxygen
D. Carbon Dioxide
Answer: C
Rationale: Oxygen mixed with refrigerant oil under pressure can
cause a violent explosion. Never use oxygen or compressed air
to pressure test or leak check a refrigeration system. Use
nitrogen or a trace gas with an electronic leak detector .
1
,2. When brazing copper refrigerant lines, what safety
equipment is essential?
A. Leather gloves only
B. Safety glasses with shaded lenses (oxy-acetylene goggles)
C. Dust mask
D. Hearing protection
Answer: B
Rationale: Brazing produces intense bright light that can
damage eyes. Shaded safety glasses or oxy-acetylene goggles
are required to protect against ultraviolet and infrared
radiation. Leather gloves, fire-resistant clothing, and adequate
ventilation are also recommended.
3. A technician is about to recover refrigerant from a system.
Before connecting hoses, what is the first safety step?
A. Open the recovery tank vapor valve
B. Put on safety glasses and gloves
2
,C. Verify the recovery tank is rated for the refrigerant type
D. Power off the unit and verify with a meter
Answer: D
Rationale: Electrical safety is paramount. Always de-energize
the equipment and verify with a meter that power is off before
connecting hoses or accessing the refrigerant circuit to prevent
electrical shock.
4. What is the maximum safe pressure for leak testing an R-
410A system with nitrogen?
A. System nameplate low-side test pressure (typically 150-250
psig)
B. 500 psig regardless of system
C. Manufacturer's specified maximum test pressure (often 400-
600 psig for high side)
D. 1.5 times the critical pressure
Answer: C
3
, Rationale: Always follow manufacturer specifications for
maximum test pressure. For R-410A systems, the high-side test
pressure is typically 400-600 psig. Exceeding rated pressure
can rupture components, causing serious injury .
5. A technician is using a ladder to access a rooftop unit. The
ladder should extend above the roof landing at least:
A. 12 inches
B. 24 inches (2 feet)
C. 36 inches (3 feet)
D. 48 inches (4 feet)
Answer: C
Rationale: OSHA requires ladders to extend at least 3 feet (36
inches) above the roof landing surface to provide a handhold for
safe transition onto the roof.
6. Electronic air cleaners can operate with internal voltages as
high as:
4
Exam| Complete 100 Real Exam Questions and Correct
Verified Answers/ Graded A+ (New!!)
1. Which of the following substances could create an
extremely dangerous condition if used to check a refrigeration
system for leaks?
A. R-22
B. Nitrogen
C. Oxygen
D. Carbon Dioxide
Answer: C
Rationale: Oxygen mixed with refrigerant oil under pressure can
cause a violent explosion. Never use oxygen or compressed air
to pressure test or leak check a refrigeration system. Use
nitrogen or a trace gas with an electronic leak detector .
1
,2. When brazing copper refrigerant lines, what safety
equipment is essential?
A. Leather gloves only
B. Safety glasses with shaded lenses (oxy-acetylene goggles)
C. Dust mask
D. Hearing protection
Answer: B
Rationale: Brazing produces intense bright light that can
damage eyes. Shaded safety glasses or oxy-acetylene goggles
are required to protect against ultraviolet and infrared
radiation. Leather gloves, fire-resistant clothing, and adequate
ventilation are also recommended.
3. A technician is about to recover refrigerant from a system.
Before connecting hoses, what is the first safety step?
A. Open the recovery tank vapor valve
B. Put on safety glasses and gloves
2
,C. Verify the recovery tank is rated for the refrigerant type
D. Power off the unit and verify with a meter
Answer: D
Rationale: Electrical safety is paramount. Always de-energize
the equipment and verify with a meter that power is off before
connecting hoses or accessing the refrigerant circuit to prevent
electrical shock.
4. What is the maximum safe pressure for leak testing an R-
410A system with nitrogen?
A. System nameplate low-side test pressure (typically 150-250
psig)
B. 500 psig regardless of system
C. Manufacturer's specified maximum test pressure (often 400-
600 psig for high side)
D. 1.5 times the critical pressure
Answer: C
3
, Rationale: Always follow manufacturer specifications for
maximum test pressure. For R-410A systems, the high-side test
pressure is typically 400-600 psig. Exceeding rated pressure
can rupture components, causing serious injury .
5. A technician is using a ladder to access a rooftop unit. The
ladder should extend above the roof landing at least:
A. 12 inches
B. 24 inches (2 feet)
C. 36 inches (3 feet)
D. 48 inches (4 feet)
Answer: C
Rationale: OSHA requires ladders to extend at least 3 feet (36
inches) above the roof landing surface to provide a handhold for
safe transition onto the roof.
6. Electronic air cleaners can operate with internal voltages as
high as:
4
