NM ES-3 New Mexico Low Voltage
Journeyman Exam Study Guide |
Complete Practice Questions &
Answers | Electrical Licensing Exam
Prep | NEC & NFPA Code Review
(Latest Edition)
NM ES-3 NEW MEXICO LOW VOLTAGE JOURNEYMAN EXAM STUDY GUIDE
COMPLETE PRACTICE QUESTIONS & ANSWERS
DOCUMENT OVERVIEW:
• This comprehensive study material contains 300 practice questions designed to
prepare you for the NM ES-3 Low Voltage Journeyman Electrical Licensing Exam,
covering all major content areas tested including NEC code applications, wiring
methods, grounding/bonding, branch circuits, services, equipment installations,
and safety standards.
• Study by reviewing each question carefully, attempting to answer before reading
the correct answer and rationale, and focusing on understanding the "why" behind
each answer to build practical knowledge applicable to field work and code
compliance.
1. According to NEC Article 300, what is the maximum number of 90-degree
bends permitted in a single conduit run without an access point?
A) 2 bends
B) 3 bends
C) 4 bends
D) 5 bends
,E) 6 bends
CORRECT ANSWER: B) 3 bends
Rationale: NEC Article 300.34 specifies that the total number of bends (including
those less than 90 degrees) in a single conduit run between pull points shall not
exceed 360 degrees. This typically translates to a maximum of four 90-degree
bends, but the actual limit is 360 degrees total. However, industry standard practice
and NEC guidance recommend no more than 3 full 90-degree bends to ensure
proper wire pulling and protection. This prevents damage to wire insulation and
allows for safe maintenance access.
2. What is the minimum wire size required for a 20-ampere branch circuit
under NEC Article 210?
A) 14 AWG
B) 12 AWG
C) 10 AWG
D) 8 AWG
E) 6 AWG
CORRECT ANSWER: B) 12 AWG
Rationale: NEC Article 210.3 requires that branch circuit conductors have an
ampacity not less than the branch circuit rating. For a 20-ampere branch circuit, 12
AWG copper wire with an ampacity of 20 amperes at 60°C is the minimum required.
While 14 AWG has a rating of 15 amperes, it cannot be used on a 20-ampere circuit
as it would be undersized and create a fire hazard. Using larger conductors is
acceptable but not required.
3. According to NEC Article 250, what is the maximum distance a grounding
electrode conductor can run from the service to the grounding electrode?
A) 25 feet
,B) 50 feet
C) 75 feet
D) 100 feet
E) Unlimited distance is permitted
CORRECT ANSWER: E) Unlimited distance is permitted
Rationale: NEC Article 250.64(A) does not specify a maximum distance for a
grounding electrode conductor. The grounding electrode conductor must be sized
according to Table 250.66 based on the size of the service entrance conductors, but
there is no distance limitation. However, the conductor must be protected from
physical damage if exposed and must be run as directly as practicable. The key
requirement is proper sizing, not distance.
4. What is the proper method for determining the size of the main bonding
jumper according to NEC Article 250?
A) Based on the size of the largest service conductor
B) Based on 12.5% of the service amperage
C) Minimum 1/0 AWG copper
D) Based on the size of the grounding electrode
E) Based on the size of the neutral conductor
CORRECT ANSWER: A) Based on the size of the largest service conductor
Rationale: NEC Table 250.66 provides sizing requirements for bonding jumpers
based on the size of the service entrance conductors. The main bonding jumper
must have an ampacity not less than the largest service entrance conductor, or if
the service entrance conductors are parallel, must be based on the equivalent size
of the parallel conductors. This ensures adequate bonding capability between the
neutral bar and equipment grounding bar in the service panel.
, 5. According to NEC Article 300, in which applications is EMT (Electrical
Metallic Tubing) permitted to be installed?
A) Only indoors in dry locations
B) Indoors and outdoors in wet locations with proper fittings
C) Indoors in dry locations and outdoors if protected from physical damage
D) All locations without restriction
E) Only in residential applications
CORRECT ANSWER: C) Indoors in dry locations and outdoors if protected from
physical damage
Rationale: NEC Article 358.12 permits EMT to be used in both wet and dry
locations; however, outdoor use requires protection from physical damage. Fittings
designed for wet locations must be used, and the installation must be arranged to
prevent water from entering the tubing. EMT is commonly used in residential,
commercial, and industrial applications wherever the conditions permit. In outdoor
locations without protection, rigid conduit or PVC is preferred.
6. What is the minimum size equipment grounding conductor required for a
circuit protected by a 30-ampere overcurrent device using copper conductors?
A) 14 AWG
B) 12 AWG
C) 10 AWG
D) 8 AWG
E) 6 AWG
CORRECT ANSWER: C) 10 AWG
Rationale: NEC Table 250.122 specifies the minimum size of equipment grounding
conductors based on the rating of the overcurrent device protecting the circuit. For
a 30-ampere overcurrent device, a 10 AWG copper equipment grounding conductor
Journeyman Exam Study Guide |
Complete Practice Questions &
Answers | Electrical Licensing Exam
Prep | NEC & NFPA Code Review
(Latest Edition)
NM ES-3 NEW MEXICO LOW VOLTAGE JOURNEYMAN EXAM STUDY GUIDE
COMPLETE PRACTICE QUESTIONS & ANSWERS
DOCUMENT OVERVIEW:
• This comprehensive study material contains 300 practice questions designed to
prepare you for the NM ES-3 Low Voltage Journeyman Electrical Licensing Exam,
covering all major content areas tested including NEC code applications, wiring
methods, grounding/bonding, branch circuits, services, equipment installations,
and safety standards.
• Study by reviewing each question carefully, attempting to answer before reading
the correct answer and rationale, and focusing on understanding the "why" behind
each answer to build practical knowledge applicable to field work and code
compliance.
1. According to NEC Article 300, what is the maximum number of 90-degree
bends permitted in a single conduit run without an access point?
A) 2 bends
B) 3 bends
C) 4 bends
D) 5 bends
,E) 6 bends
CORRECT ANSWER: B) 3 bends
Rationale: NEC Article 300.34 specifies that the total number of bends (including
those less than 90 degrees) in a single conduit run between pull points shall not
exceed 360 degrees. This typically translates to a maximum of four 90-degree
bends, but the actual limit is 360 degrees total. However, industry standard practice
and NEC guidance recommend no more than 3 full 90-degree bends to ensure
proper wire pulling and protection. This prevents damage to wire insulation and
allows for safe maintenance access.
2. What is the minimum wire size required for a 20-ampere branch circuit
under NEC Article 210?
A) 14 AWG
B) 12 AWG
C) 10 AWG
D) 8 AWG
E) 6 AWG
CORRECT ANSWER: B) 12 AWG
Rationale: NEC Article 210.3 requires that branch circuit conductors have an
ampacity not less than the branch circuit rating. For a 20-ampere branch circuit, 12
AWG copper wire with an ampacity of 20 amperes at 60°C is the minimum required.
While 14 AWG has a rating of 15 amperes, it cannot be used on a 20-ampere circuit
as it would be undersized and create a fire hazard. Using larger conductors is
acceptable but not required.
3. According to NEC Article 250, what is the maximum distance a grounding
electrode conductor can run from the service to the grounding electrode?
A) 25 feet
,B) 50 feet
C) 75 feet
D) 100 feet
E) Unlimited distance is permitted
CORRECT ANSWER: E) Unlimited distance is permitted
Rationale: NEC Article 250.64(A) does not specify a maximum distance for a
grounding electrode conductor. The grounding electrode conductor must be sized
according to Table 250.66 based on the size of the service entrance conductors, but
there is no distance limitation. However, the conductor must be protected from
physical damage if exposed and must be run as directly as practicable. The key
requirement is proper sizing, not distance.
4. What is the proper method for determining the size of the main bonding
jumper according to NEC Article 250?
A) Based on the size of the largest service conductor
B) Based on 12.5% of the service amperage
C) Minimum 1/0 AWG copper
D) Based on the size of the grounding electrode
E) Based on the size of the neutral conductor
CORRECT ANSWER: A) Based on the size of the largest service conductor
Rationale: NEC Table 250.66 provides sizing requirements for bonding jumpers
based on the size of the service entrance conductors. The main bonding jumper
must have an ampacity not less than the largest service entrance conductor, or if
the service entrance conductors are parallel, must be based on the equivalent size
of the parallel conductors. This ensures adequate bonding capability between the
neutral bar and equipment grounding bar in the service panel.
, 5. According to NEC Article 300, in which applications is EMT (Electrical
Metallic Tubing) permitted to be installed?
A) Only indoors in dry locations
B) Indoors and outdoors in wet locations with proper fittings
C) Indoors in dry locations and outdoors if protected from physical damage
D) All locations without restriction
E) Only in residential applications
CORRECT ANSWER: C) Indoors in dry locations and outdoors if protected from
physical damage
Rationale: NEC Article 358.12 permits EMT to be used in both wet and dry
locations; however, outdoor use requires protection from physical damage. Fittings
designed for wet locations must be used, and the installation must be arranged to
prevent water from entering the tubing. EMT is commonly used in residential,
commercial, and industrial applications wherever the conditions permit. In outdoor
locations without protection, rigid conduit or PVC is preferred.
6. What is the minimum size equipment grounding conductor required for a
circuit protected by a 30-ampere overcurrent device using copper conductors?
A) 14 AWG
B) 12 AWG
C) 10 AWG
D) 8 AWG
E) 6 AWG
CORRECT ANSWER: C) 10 AWG
Rationale: NEC Table 250.122 specifies the minimum size of equipment grounding
conductors based on the rating of the overcurrent device protecting the circuit. For
a 30-ampere overcurrent device, a 10 AWG copper equipment grounding conductor
