NYC DOB MASTER ELECTRICIAN LICENSE EXAM – QUESTIONS AND ANSWERS |
VERIFIED AND WELL DETAILED ANSWERS |EXAM TESTBANK | PLUS
RATIONALES | DOWNLOAD AND PASS | LATEST EXAM UPDATE 2026/2027
Core Domains
1. Electrical Theory and Fundamentals
2. National Electrical Code (NEC) Regulations
3. NYC Electrical Code (Local Law 96) Amendments
4. Overcurrent Protection and Coordination
5. Grounding and Bonding Systems
6. Wiring Methods and Materials
7. Motor and Transformer Applications
8. Emergency Systems and Standby Power
9. Fire Alarm and Life Safety Systems
10. Construction Drawings and Specifications
Introduction
This comprehensive examination is designed to rigorously assess the knowledge and
practical skills required of a Master Electrician operating within the jurisdiction of
the New York City Department of Buildings. The test evaluates a candidate's
mastery of both the National Electrical Code and the specific, more stringent
amendments found within the NYC Electrical Code. Candidates will be presented
with a mix of direct-knowledge questions and complex, scenario-based problems
that demand critical thinking and the application of safety standards, legal
compliance, and professional ethics. This assessment emphasizes real-world
decision-making, preparing the electrician to oversee projects, manage teams, and
ensure the absolute safety and reliability of electrical systems in one of the world's
most demanding urban environments.
,SECTION ONE: QUESTIONS 1–50
Question 1
A 400-ampere, 3-phase, 480-volt feeder is installed in a commercial building
using parallel conductors in two separate raceways. Per the NEC, what is the
minimum size of the equipment grounding conductor (EGC) required to be
installed in each raceway?
A. 3 AWG
B. 1 AWG
C. 1/0 AWG
D. 2/0 AWG
🟢 Correct Answer: B. 1 AWG
🔴 Explanation: When conductors are paralleled in multiple raceways, an EGC
must be installed in each raceway. The size is based on the overcurrent protective
device rating, which is 400A. Per Table 250.122, a 400A circuit requires a 1 AWG
copper EGC. The EGC is not divided; each raceway must contain a full-size EGC of
1 AWG.
Question 2
Given a 3-phase, 4-wire, 208Y/120-volt system, the maximum allowable voltage
drop for a branch circuit supplying power to a sensitive piece of electronic
equipment is most strictly recommended to not exceed:
A. 1%
B. 2%
C. 3%
D. 5%
🟢 Correct Answer: A. 1%
,🔴 Explanation: While the NEC recommends a maximum total voltage drop of 5%
for feeders and branch circuits combined, and 3% for a branch circuit, a stricter
recommendation of 1% is often applied to sensitive electronic equipment to
prevent malfunction and ensure proper operation.
Question 3
A 50-foot run of rigid metal conduit (RMC) is installed in a location subject to
severe physical damage. Which of the following is a code-compliant method of
providing additional protection?
A. Installing the conduit in a concrete encasement a minimum of 2 inches thick
B. Using a Schedule 80 PVC conduit as a sleeve over the RMC
C. Burying the conduit a minimum of 18 inches below grade
D. Installing a steel guard post or bollard designed for the application
🟢 Correct Answer: D. Installing a steel guard post or bollard designed for the
application
🔴 Explanation: While the code requires raceways to be protected from physical
damage, the specific, enforceable method often involves structural barriers.
Concrete encasement, while protective, is not always a code-specified
requirement in lieu of a physical barrier. A steel guard post or bollard is a
standard and directly compliant method of protection from vehicle or impact
damage.
Question 4
In a dwelling unit, what is the maximum load that can be connected to a 15-
ampere branch circuit used to supply lighting and general-purpose receptacles?
, A. 12 amperes
B. 15 amperes
C. 16 amperes
D. 20 amperes
🟢 Correct Answer: A. 12 amperes
🔴 Explanation: For a continuous load (defined as a load where the maximum
current is expected to continue for 3 hours or more), the branch circuit conductor
must be sized at 125% of the continuous load. For a 15A circuit, the maximum
continuous load is 15A / 1.25 = 12A. Lighting and general receptacles are
generally considered continuous loads.
Question 5
A switchboard is located in a room with a 200-ampere main circuit breaker. The
room is designated as an "electrical room" and contains no other combustible
materials. What is the minimum required working space in front of the
switchboard?
A. 3 feet
B. 3.5 feet
C. 4 feet
D. 6 feet
🟢 Correct Answer: B. 3.5 feet
🔴 Explanation: NEC Table 110.26(A)(1) specifies the working space for
equipment likely to require examination, adjustment, servicing, or maintenance.
For a 200A switchboard, the voltage is likely below 600V. If the equipment is on a
grounded surface (typically concrete), the distance from the exposed live parts to
the wall or nearest surface is 3 feet. However, the question states a switchboard
VERIFIED AND WELL DETAILED ANSWERS |EXAM TESTBANK | PLUS
RATIONALES | DOWNLOAD AND PASS | LATEST EXAM UPDATE 2026/2027
Core Domains
1. Electrical Theory and Fundamentals
2. National Electrical Code (NEC) Regulations
3. NYC Electrical Code (Local Law 96) Amendments
4. Overcurrent Protection and Coordination
5. Grounding and Bonding Systems
6. Wiring Methods and Materials
7. Motor and Transformer Applications
8. Emergency Systems and Standby Power
9. Fire Alarm and Life Safety Systems
10. Construction Drawings and Specifications
Introduction
This comprehensive examination is designed to rigorously assess the knowledge and
practical skills required of a Master Electrician operating within the jurisdiction of
the New York City Department of Buildings. The test evaluates a candidate's
mastery of both the National Electrical Code and the specific, more stringent
amendments found within the NYC Electrical Code. Candidates will be presented
with a mix of direct-knowledge questions and complex, scenario-based problems
that demand critical thinking and the application of safety standards, legal
compliance, and professional ethics. This assessment emphasizes real-world
decision-making, preparing the electrician to oversee projects, manage teams, and
ensure the absolute safety and reliability of electrical systems in one of the world's
most demanding urban environments.
,SECTION ONE: QUESTIONS 1–50
Question 1
A 400-ampere, 3-phase, 480-volt feeder is installed in a commercial building
using parallel conductors in two separate raceways. Per the NEC, what is the
minimum size of the equipment grounding conductor (EGC) required to be
installed in each raceway?
A. 3 AWG
B. 1 AWG
C. 1/0 AWG
D. 2/0 AWG
🟢 Correct Answer: B. 1 AWG
🔴 Explanation: When conductors are paralleled in multiple raceways, an EGC
must be installed in each raceway. The size is based on the overcurrent protective
device rating, which is 400A. Per Table 250.122, a 400A circuit requires a 1 AWG
copper EGC. The EGC is not divided; each raceway must contain a full-size EGC of
1 AWG.
Question 2
Given a 3-phase, 4-wire, 208Y/120-volt system, the maximum allowable voltage
drop for a branch circuit supplying power to a sensitive piece of electronic
equipment is most strictly recommended to not exceed:
A. 1%
B. 2%
C. 3%
D. 5%
🟢 Correct Answer: A. 1%
,🔴 Explanation: While the NEC recommends a maximum total voltage drop of 5%
for feeders and branch circuits combined, and 3% for a branch circuit, a stricter
recommendation of 1% is often applied to sensitive electronic equipment to
prevent malfunction and ensure proper operation.
Question 3
A 50-foot run of rigid metal conduit (RMC) is installed in a location subject to
severe physical damage. Which of the following is a code-compliant method of
providing additional protection?
A. Installing the conduit in a concrete encasement a minimum of 2 inches thick
B. Using a Schedule 80 PVC conduit as a sleeve over the RMC
C. Burying the conduit a minimum of 18 inches below grade
D. Installing a steel guard post or bollard designed for the application
🟢 Correct Answer: D. Installing a steel guard post or bollard designed for the
application
🔴 Explanation: While the code requires raceways to be protected from physical
damage, the specific, enforceable method often involves structural barriers.
Concrete encasement, while protective, is not always a code-specified
requirement in lieu of a physical barrier. A steel guard post or bollard is a
standard and directly compliant method of protection from vehicle or impact
damage.
Question 4
In a dwelling unit, what is the maximum load that can be connected to a 15-
ampere branch circuit used to supply lighting and general-purpose receptacles?
, A. 12 amperes
B. 15 amperes
C. 16 amperes
D. 20 amperes
🟢 Correct Answer: A. 12 amperes
🔴 Explanation: For a continuous load (defined as a load where the maximum
current is expected to continue for 3 hours or more), the branch circuit conductor
must be sized at 125% of the continuous load. For a 15A circuit, the maximum
continuous load is 15A / 1.25 = 12A. Lighting and general receptacles are
generally considered continuous loads.
Question 5
A switchboard is located in a room with a 200-ampere main circuit breaker. The
room is designated as an "electrical room" and contains no other combustible
materials. What is the minimum required working space in front of the
switchboard?
A. 3 feet
B. 3.5 feet
C. 4 feet
D. 6 feet
🟢 Correct Answer: B. 3.5 feet
🔴 Explanation: NEC Table 110.26(A)(1) specifies the working space for
equipment likely to require examination, adjustment, servicing, or maintenance.
For a 200A switchboard, the voltage is likely below 600V. If the equipment is on a
grounded surface (typically concrete), the distance from the exposed live parts to
the wall or nearest surface is 3 feet. However, the question states a switchboard
