Maryland HVACR Master Restricted
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
Pdf
1. A licensed HVACR Master Restricted contractor in Maryland is
primarily authorized to:
A. Perform all HVACR work without limitation statewide
B. Install and service only the restricted category listed on the license
C. Perform electrical contracting without supervision
D. Inspect commercial buildings for code compliance
B. Perform and service only the restricted category listed on the license
Rationale: A Maryland HVACR Master Restricted license limits the contractor
to the specialty classification approved by the licensing board, such as forced
air, hydronic, refrigeration, or ventilation systems. It does not grant unlimited
HVACR authority.
2. Which organization publishes the National Electrical Code commonly
referenced during HVACR installations?
, A. ASHRAE
B. NFPA
C. ICC
D. SMACNA
B. NFPA
Rationale: The National Fire Protection Association publishes the National
Electrical Code, which governs electrical safety requirements frequently
encountered during HVACR installations and servicing.
3. When brazing refrigerant piping, nitrogen should be flowed through
the tubing primarily to:
A. Increase refrigerant pressure
B. Speed up brazing temperature
C. Prevent internal oxidation and scale formation
D. Reduce refrigerant charge requirements
C. Prevent internal oxidation and scale formation
Rationale: Flowing nitrogen while brazing prevents oxidation inside copper
tubing, reducing contamination that could damage compressors, expansion
valves, and other refrigeration system components.
4. A technician measures 480 volts across a three-phase disconnect but
reads zero volts across one fuse. This condition most likely indicates:
A. A grounded compressor
B. An open fuse
C. Excessive superheat
D. A defective thermostat
B. An open fuse
,Rationale: Voltage across a fuse indicates a difference in electrical potential.
A good fuse typically shows near-zero voltage drop, while an open fuse
shows full line voltage across it.
5. The primary purpose of a suction accumulator is to:
A. Increase compressor discharge pressure
B. Store liquid refrigerant before the condenser
C. Prevent liquid refrigerant from entering the compressor
D. Remove moisture from refrigerant vapor
C. Prevent liquid refrigerant from entering the compressor
Rationale: Suction accumulators protect compressors from liquid slugging by
trapping excess liquid refrigerant before it reaches the compressor suction
inlet.
6. Which refrigerant safety classification indicates lower toxicity and no
flame propagation?
A. B3
B. A3
C. B1
D. A1
D. A1
Rationale: Refrigerants classified as A1 by ASHRAE have lower toxicity and
no flame propagation characteristics, making them among the safest
refrigerants to handle under normal conditions.
7. An HVACR contractor must obtain permits before beginning regulated
work primarily to:
A. Increase project profitability
B. Ensure code compliance and inspection approval
C. Avoid purchasing insurance
D. Eliminate manufacturer warranties
, B. Ensure code compliance and inspection approval
Rationale: Permits allow local authorities to review and inspect work to
ensure installations comply with applicable mechanical, electrical, fuel gas,
and safety codes.
8. What is the most common cause of compressor failure in air-
conditioning systems?
A. Excessive condenser airflow
B. Incorrect thermostat anticipator settings
C. Contaminated or improper refrigerant conditions
D. Oversized return air ducts
C. Contaminated or improper refrigerant conditions
Rationale: Compressor failures are commonly linked to contamination,
overheating, improper refrigerant charge, moisture, acid formation, or poor
lubrication conditions.
9. A psychrometer is used to measure:
A. Refrigerant pressure
B. Wet-bulb and dry-bulb temperatures
C. Electrical resistance
D. Gas manifold pressure
B. Wet-bulb and dry-bulb temperatures
Rationale: Psychrometers measure wet-bulb and dry-bulb temperatures,
allowing technicians to determine relative humidity and other psychrometric
properties.
10. The primary function of a thermostatic expansion valve is to:
A. Increase condenser efficiency
B. Maintain proper evaporator superheat
Exam Practice Questions And Correct
Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A licensed HVACR Master Restricted contractor in Maryland is
primarily authorized to:
A. Perform all HVACR work without limitation statewide
B. Install and service only the restricted category listed on the license
C. Perform electrical contracting without supervision
D. Inspect commercial buildings for code compliance
B. Perform and service only the restricted category listed on the license
Rationale: A Maryland HVACR Master Restricted license limits the contractor
to the specialty classification approved by the licensing board, such as forced
air, hydronic, refrigeration, or ventilation systems. It does not grant unlimited
HVACR authority.
2. Which organization publishes the National Electrical Code commonly
referenced during HVACR installations?
, A. ASHRAE
B. NFPA
C. ICC
D. SMACNA
B. NFPA
Rationale: The National Fire Protection Association publishes the National
Electrical Code, which governs electrical safety requirements frequently
encountered during HVACR installations and servicing.
3. When brazing refrigerant piping, nitrogen should be flowed through
the tubing primarily to:
A. Increase refrigerant pressure
B. Speed up brazing temperature
C. Prevent internal oxidation and scale formation
D. Reduce refrigerant charge requirements
C. Prevent internal oxidation and scale formation
Rationale: Flowing nitrogen while brazing prevents oxidation inside copper
tubing, reducing contamination that could damage compressors, expansion
valves, and other refrigeration system components.
4. A technician measures 480 volts across a three-phase disconnect but
reads zero volts across one fuse. This condition most likely indicates:
A. A grounded compressor
B. An open fuse
C. Excessive superheat
D. A defective thermostat
B. An open fuse
,Rationale: Voltage across a fuse indicates a difference in electrical potential.
A good fuse typically shows near-zero voltage drop, while an open fuse
shows full line voltage across it.
5. The primary purpose of a suction accumulator is to:
A. Increase compressor discharge pressure
B. Store liquid refrigerant before the condenser
C. Prevent liquid refrigerant from entering the compressor
D. Remove moisture from refrigerant vapor
C. Prevent liquid refrigerant from entering the compressor
Rationale: Suction accumulators protect compressors from liquid slugging by
trapping excess liquid refrigerant before it reaches the compressor suction
inlet.
6. Which refrigerant safety classification indicates lower toxicity and no
flame propagation?
A. B3
B. A3
C. B1
D. A1
D. A1
Rationale: Refrigerants classified as A1 by ASHRAE have lower toxicity and
no flame propagation characteristics, making them among the safest
refrigerants to handle under normal conditions.
7. An HVACR contractor must obtain permits before beginning regulated
work primarily to:
A. Increase project profitability
B. Ensure code compliance and inspection approval
C. Avoid purchasing insurance
D. Eliminate manufacturer warranties
, B. Ensure code compliance and inspection approval
Rationale: Permits allow local authorities to review and inspect work to
ensure installations comply with applicable mechanical, electrical, fuel gas,
and safety codes.
8. What is the most common cause of compressor failure in air-
conditioning systems?
A. Excessive condenser airflow
B. Incorrect thermostat anticipator settings
C. Contaminated or improper refrigerant conditions
D. Oversized return air ducts
C. Contaminated or improper refrigerant conditions
Rationale: Compressor failures are commonly linked to contamination,
overheating, improper refrigerant charge, moisture, acid formation, or poor
lubrication conditions.
9. A psychrometer is used to measure:
A. Refrigerant pressure
B. Wet-bulb and dry-bulb temperatures
C. Electrical resistance
D. Gas manifold pressure
B. Wet-bulb and dry-bulb temperatures
Rationale: Psychrometers measure wet-bulb and dry-bulb temperatures,
allowing technicians to determine relative humidity and other psychrometric
properties.
10. The primary function of a thermostatic expansion valve is to:
A. Increase condenser efficiency
B. Maintain proper evaporator superheat
