1|Page
District of Columbia (DC) Journeyman A/C &
Refrigeration (312) Exam | Latest Verified Questions
and Detailed Answers | Graded A+
OVERVIEW DESCRIPTION:
The District of Columbia (DC) Journeyman A/C & Refrigeration (312) Exam is a comprehensive,
multiple-choice assessment designed to certify technicians in the installation, service,
troubleshooting, and code compliance of both residential and commercial HVACR systems. The
exam rigorously tests a candidate’s depth of knowledge across core mechanical and electrical
disciplines, including refrigeration cycle theory, system components (compressors, metering
devices, heat exchangers), advanced electrical troubleshooting (motors, capacitors, control
circuits, and schematics), and combustion analysis for gas/oil furnaces. A significant portion of
the exam is dedicated to safety and regulatory compliance, emphasizing the International
Mechanical Code (IMC), EPA Section 608 refrigerant handling regulations, and ASHRAE
standards. Candidates must demonstrate proficiency in diagnostic reasoning—such as
interpreting pressure-temperature relationships, calculating superheat/subcooling, and
identifying mechanical failures—alongside practical application of heat load calculations, duct
design, and modern energy efficiency protocols.
QUESTION 1
A single-phase compressor motor draws 12 amps at 120 volts. What is the apparent
power (VA) of the motor?
A) 10 VA
B) 120 VA
C) 1440 VA
D) 2880 VA
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: Apparent power in VA is calculated as Volts × Amps (120V × 12A =
1440VA), which represents the total power drawn from the source before power factor
is considered.
QUESTION 2
According to the IMC, what is the minimum allowable clearance for a forced-air
furnace from combustible materials unless the unit is specifically listed for less
clearance?
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A) 0 inches
B) 3 inches
C) 6 inches
D) 12 inches
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: The International Mechanical Code typically requires a minimum
of 6 inches clearance from combustibles for furnaces unless the manufacturer’s listing
label specifies a reduced clearance.
QUESTION 3
Which refrigerant has the lowest global warming potential (GWP) among the following
options?
A) R-22
B) R-404A
C) R-410A
D) R-744
CORRECT ANSWER: ✓ D ✓
EXPERT RATIONALE: R-744 (CO2) has a GWP of 1, significantly lower than synthetic
refrigerants like R-22, R-410A, and R-404A.
QUESTION 4
What is the primary purpose of a start capacitor in a split-phase motor?
A) To reduce running current
B) To provide high starting torque
C) To improve power factor
D) To filter electrical noise
CORRECT ANSWER: ✓ B ✓
EXPERT RATIONALE: A start capacitor provides a boost of energy to create a stronger
magnetic field during startup, resulting in high starting torque to get the motor and
load moving.
,3|Page
QUESTION 5
A system using R-410A has a suction pressure of 118 psig and a liquid line pressure of
330 psig. What is the approximate condenser split on an 85°F day?
A) 10°F
B) 20°F
C) 30°F
D) 40°F
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: 330 psig R-410A corresponds to roughly 115°F SCT. 115°F - 85°F
ambient = 30°F condenser split.
QUESTION 6
What does a "standing pressure" test in refrigeration refer to?
A) The system pressure while operating
B) The pressure exerted by the oil charge
C) The system pressure when idle and equalized
D) The pressure at the expansion valve inlet
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: Standing pressure (or static pressure) is the pressure in a
system that has been shut off long enough for pressures to equalize between the high
and low sides.
QUESTION 7
When brazing copper tubing for refrigeration systems, what gas is typically used as
the inert atmosphere to prevent oxidation?
A) Oxygen
B) Acetylene
C) Nitrogen
D) Propane
, 4|Page
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: Dry nitrogen is flowed through the system during brazing to
displace oxygen and prevent the formation of copper oxide scale inside the tubing.
QUESTION 8
Which component is responsible for changing a low-pressure vapor to a high-
pressure vapor?
A) Evaporator
B) Condenser
C) Compressor
D) Metering device
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: The compressor mechanically increases the pressure and
temperature of the refrigerant vapor, discharging it as high-pressure superheated
vapor.
QUESTION 9
What is the maximum allowable evacuation level required by most manufacturers
when opening a new commercial system?
A) 5,000 microns
B) 2,000 microns
C) 1,000 microns
D) 500 microns
CORRECT ANSWER: ✓ D ✓
EXPERT RATIONALE: A deep vacuum of 500 microns or lower is required to ensure
that non-condensables and moisture are removed, preventing acid formation and
inefficiency.
QUESTION 10
A technician measures 75V on a terminal of a dual-run capacitor labeled "C to HERM"
and 0V on "C to FAN." The common terminal is live. What is the likely fault?
District of Columbia (DC) Journeyman A/C &
Refrigeration (312) Exam | Latest Verified Questions
and Detailed Answers | Graded A+
OVERVIEW DESCRIPTION:
The District of Columbia (DC) Journeyman A/C & Refrigeration (312) Exam is a comprehensive,
multiple-choice assessment designed to certify technicians in the installation, service,
troubleshooting, and code compliance of both residential and commercial HVACR systems. The
exam rigorously tests a candidate’s depth of knowledge across core mechanical and electrical
disciplines, including refrigeration cycle theory, system components (compressors, metering
devices, heat exchangers), advanced electrical troubleshooting (motors, capacitors, control
circuits, and schematics), and combustion analysis for gas/oil furnaces. A significant portion of
the exam is dedicated to safety and regulatory compliance, emphasizing the International
Mechanical Code (IMC), EPA Section 608 refrigerant handling regulations, and ASHRAE
standards. Candidates must demonstrate proficiency in diagnostic reasoning—such as
interpreting pressure-temperature relationships, calculating superheat/subcooling, and
identifying mechanical failures—alongside practical application of heat load calculations, duct
design, and modern energy efficiency protocols.
QUESTION 1
A single-phase compressor motor draws 12 amps at 120 volts. What is the apparent
power (VA) of the motor?
A) 10 VA
B) 120 VA
C) 1440 VA
D) 2880 VA
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: Apparent power in VA is calculated as Volts × Amps (120V × 12A =
1440VA), which represents the total power drawn from the source before power factor
is considered.
QUESTION 2
According to the IMC, what is the minimum allowable clearance for a forced-air
furnace from combustible materials unless the unit is specifically listed for less
clearance?
,2|Page
A) 0 inches
B) 3 inches
C) 6 inches
D) 12 inches
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: The International Mechanical Code typically requires a minimum
of 6 inches clearance from combustibles for furnaces unless the manufacturer’s listing
label specifies a reduced clearance.
QUESTION 3
Which refrigerant has the lowest global warming potential (GWP) among the following
options?
A) R-22
B) R-404A
C) R-410A
D) R-744
CORRECT ANSWER: ✓ D ✓
EXPERT RATIONALE: R-744 (CO2) has a GWP of 1, significantly lower than synthetic
refrigerants like R-22, R-410A, and R-404A.
QUESTION 4
What is the primary purpose of a start capacitor in a split-phase motor?
A) To reduce running current
B) To provide high starting torque
C) To improve power factor
D) To filter electrical noise
CORRECT ANSWER: ✓ B ✓
EXPERT RATIONALE: A start capacitor provides a boost of energy to create a stronger
magnetic field during startup, resulting in high starting torque to get the motor and
load moving.
,3|Page
QUESTION 5
A system using R-410A has a suction pressure of 118 psig and a liquid line pressure of
330 psig. What is the approximate condenser split on an 85°F day?
A) 10°F
B) 20°F
C) 30°F
D) 40°F
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: 330 psig R-410A corresponds to roughly 115°F SCT. 115°F - 85°F
ambient = 30°F condenser split.
QUESTION 6
What does a "standing pressure" test in refrigeration refer to?
A) The system pressure while operating
B) The pressure exerted by the oil charge
C) The system pressure when idle and equalized
D) The pressure at the expansion valve inlet
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: Standing pressure (or static pressure) is the pressure in a
system that has been shut off long enough for pressures to equalize between the high
and low sides.
QUESTION 7
When brazing copper tubing for refrigeration systems, what gas is typically used as
the inert atmosphere to prevent oxidation?
A) Oxygen
B) Acetylene
C) Nitrogen
D) Propane
, 4|Page
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: Dry nitrogen is flowed through the system during brazing to
displace oxygen and prevent the formation of copper oxide scale inside the tubing.
QUESTION 8
Which component is responsible for changing a low-pressure vapor to a high-
pressure vapor?
A) Evaporator
B) Condenser
C) Compressor
D) Metering device
CORRECT ANSWER: ✓ C ✓
EXPERT RATIONALE: The compressor mechanically increases the pressure and
temperature of the refrigerant vapor, discharging it as high-pressure superheated
vapor.
QUESTION 9
What is the maximum allowable evacuation level required by most manufacturers
when opening a new commercial system?
A) 5,000 microns
B) 2,000 microns
C) 1,000 microns
D) 500 microns
CORRECT ANSWER: ✓ D ✓
EXPERT RATIONALE: A deep vacuum of 500 microns or lower is required to ensure
that non-condensables and moisture are removed, preventing acid formation and
inefficiency.
QUESTION 10
A technician measures 75V on a terminal of a dual-run capacitor labeled "C to HERM"
and 0V on "C to FAN." The common terminal is live. What is the likely fault?
