New Mexico (NM) EL-1 Electrical Distribution Systems,
including Transmission Lines Practice Exam Questions
And Correct Answers (Verified Answers) Plus
Explanation 2026.
Certification EL-1 Journeyman Electrical Distribution Systems (including Transmission Lines)
Licensing
New Mexico Regulation & Licensing Department (NMRLD)
Authority
NESC (current edition), NEC (current edition), NMAC 14.10.4 & 14.10.25, OSHA 1910.2
Primary Codes
NFPA 70E
Exam Provider PSI Services
Safety & PPE, Overhead & Underground Construction, Transformers & Substations,
Focus Areas
Protective Devices, Electrical Theory, NM Codes & Regulations
1. According to NESC, what is the minimum approach distance (MAD) for qualified
workers on energized 25 kV lines?
A) 2 ft 1 in
B) 2 ft 4 in
C) 2 ft 7 in
D) 3 ft 0 in
,Correct Answer: C
*Explanation: NESC Table 410-1 specifies minimum approach distances based on
voltage and required transient overvoltage. For 25 kV phase-to-phase, the listed
distance for qualified workers is 2 ft 7 in. *
2. Which OSHA standard specifically governs safety requirements for electric power
generation, transmission, and distribution work?
A) 29 CFR 1910.1200 (Hazard Communication)
B) 29 CFR 1910.269
C) 29 CFR 1926.1402 (Cranes)
D) 29 CFR 1910.333 (Electrical safe work practices)
Correct Answer: B
Explanation: OSHA 1910.269 is the dedicated standard for power generation, transmission,
and distribution, covering minimum approach distances, PPE, and work practices for line
workers.
3. Under NFPA 70E, what is the primary factor used to determine the required PPE
category for energized work?
A) The worker's years of experience
B) The incident energy analysis or task-based tables
C) The color of the arc-rated clothing
D) The voltage level only
Correct Answer: B
*Explanation: NFPA 70E requires PPE to be selected based on the incident energy
analysis performed for the specific equipment or, alternatively, using the task-based PPE
tables. Arc flash boundaries and incident energy levels determine the PPE category. *
,4. A crew is preparing to work on an overhead distribution line reported de-energized.
What must be verified first?
A) That the customer requested the outage
B) That the conductor insulation looks intact
C) Absence of voltage using approved testing methods and proper PPE
D) That the pole is properly painted and numbered
Correct Answer: C
*Explanation: A line must always be tested and verified de-energized before work begins
to prevent fatal shock. Dispatch reports are not sufficient verification; testing for
absence of voltage is mandatory under OSHA 1910.269. *
5. The minimum approach distance (MAD) for a 15 kV uninsulated overhead
line under OSHA 1910.269 is:
A) 10 ft
B) 12 ft
C) 15 ft
D) 18 ft
Correct Answer: B
*Explanation: OSHA Table 1-1 (1910.269) specifies a minimum approach distance of 12
feet for uninsulated conductors up to 15 kV phase-to-phase. This distance accounts for
required transient overvoltage and worker safety margins. *
6. In a lockout/tagout (LOTO) procedure for a high-voltage breaker, which step must be
performed first?
A) Apply the lock
B) Verify zero voltage with a test instrument
C) Remove the fuse
D) Notify the control room
, Correct Answer: B
*Explanation: OSHA 1910.333 and 1910.269 require verification of de-energization
(testing for absence of voltage) before applying LOTO devices. Verification must be
performed with an adequately rated voltage detector. *
7. During switching, a journeyman notices a possible backfeed source from a customer
generator. What is the best action?
A) Continue switching because backfeed is unlikely
B) Stop and verify isolation, including customer generation, before grounding and work
C) Assume reclosers will trip and protect the crew
D) Ignore it and rely only on rubber gloves
Correct Answer: B
*Explanation: Backfeed from customer-owned generation (e.g., standby generators, solar
PV) is a known hazard. All potential backfeed sources must be identified, isolated, and
tagged before work proceeds. OSHA 1910.269 requires that all possible sources of
energy be considered. *
8. What is the purpose of temporary protective grounding in distribution line work?
A) To improve power factor
B) To create an equipotential zone and prevent shock from induced voltage
C) To increase line voltage for testing
D) To reduce sag in conductors
Correct Answer: B
Explanation: Temporary protective grounding creates an equipotential zone by bonding all
phases and the neutral together and to ground. This prevents dangerous step and touch
potentials and dissipates induced voltage from nearby energized lines.
including Transmission Lines Practice Exam Questions
And Correct Answers (Verified Answers) Plus
Explanation 2026.
Certification EL-1 Journeyman Electrical Distribution Systems (including Transmission Lines)
Licensing
New Mexico Regulation & Licensing Department (NMRLD)
Authority
NESC (current edition), NEC (current edition), NMAC 14.10.4 & 14.10.25, OSHA 1910.2
Primary Codes
NFPA 70E
Exam Provider PSI Services
Safety & PPE, Overhead & Underground Construction, Transformers & Substations,
Focus Areas
Protective Devices, Electrical Theory, NM Codes & Regulations
1. According to NESC, what is the minimum approach distance (MAD) for qualified
workers on energized 25 kV lines?
A) 2 ft 1 in
B) 2 ft 4 in
C) 2 ft 7 in
D) 3 ft 0 in
,Correct Answer: C
*Explanation: NESC Table 410-1 specifies minimum approach distances based on
voltage and required transient overvoltage. For 25 kV phase-to-phase, the listed
distance for qualified workers is 2 ft 7 in. *
2. Which OSHA standard specifically governs safety requirements for electric power
generation, transmission, and distribution work?
A) 29 CFR 1910.1200 (Hazard Communication)
B) 29 CFR 1910.269
C) 29 CFR 1926.1402 (Cranes)
D) 29 CFR 1910.333 (Electrical safe work practices)
Correct Answer: B
Explanation: OSHA 1910.269 is the dedicated standard for power generation, transmission,
and distribution, covering minimum approach distances, PPE, and work practices for line
workers.
3. Under NFPA 70E, what is the primary factor used to determine the required PPE
category for energized work?
A) The worker's years of experience
B) The incident energy analysis or task-based tables
C) The color of the arc-rated clothing
D) The voltage level only
Correct Answer: B
*Explanation: NFPA 70E requires PPE to be selected based on the incident energy
analysis performed for the specific equipment or, alternatively, using the task-based PPE
tables. Arc flash boundaries and incident energy levels determine the PPE category. *
,4. A crew is preparing to work on an overhead distribution line reported de-energized.
What must be verified first?
A) That the customer requested the outage
B) That the conductor insulation looks intact
C) Absence of voltage using approved testing methods and proper PPE
D) That the pole is properly painted and numbered
Correct Answer: C
*Explanation: A line must always be tested and verified de-energized before work begins
to prevent fatal shock. Dispatch reports are not sufficient verification; testing for
absence of voltage is mandatory under OSHA 1910.269. *
5. The minimum approach distance (MAD) for a 15 kV uninsulated overhead
line under OSHA 1910.269 is:
A) 10 ft
B) 12 ft
C) 15 ft
D) 18 ft
Correct Answer: B
*Explanation: OSHA Table 1-1 (1910.269) specifies a minimum approach distance of 12
feet for uninsulated conductors up to 15 kV phase-to-phase. This distance accounts for
required transient overvoltage and worker safety margins. *
6. In a lockout/tagout (LOTO) procedure for a high-voltage breaker, which step must be
performed first?
A) Apply the lock
B) Verify zero voltage with a test instrument
C) Remove the fuse
D) Notify the control room
, Correct Answer: B
*Explanation: OSHA 1910.333 and 1910.269 require verification of de-energization
(testing for absence of voltage) before applying LOTO devices. Verification must be
performed with an adequately rated voltage detector. *
7. During switching, a journeyman notices a possible backfeed source from a customer
generator. What is the best action?
A) Continue switching because backfeed is unlikely
B) Stop and verify isolation, including customer generation, before grounding and work
C) Assume reclosers will trip and protect the crew
D) Ignore it and rely only on rubber gloves
Correct Answer: B
*Explanation: Backfeed from customer-owned generation (e.g., standby generators, solar
PV) is a known hazard. All potential backfeed sources must be identified, isolated, and
tagged before work proceeds. OSHA 1910.269 requires that all possible sources of
energy be considered. *
8. What is the purpose of temporary protective grounding in distribution line work?
A) To improve power factor
B) To create an equipotential zone and prevent shock from induced voltage
C) To increase line voltage for testing
D) To reduce sag in conductors
Correct Answer: B
Explanation: Temporary protective grounding creates an equipotential zone by bonding all
phases and the neutral together and to ground. This prevents dangerous step and touch
potentials and dissipates induced voltage from nearby energized lines.
