New Mexico EL-1J Electrical Distribution Journeyman Exam
Practice
QUESTION 1
A journeyman electrician is planning to work on a 25 kV overhead
distribution line. According to OSHA 1910.269, what is the PRIMARY factor
that determines the minimum approach distance?
A) The phase-to-ground voltage only
B) The phase-to-phase voltage and the type of work being performed
C) The maximum anticipated transient overvoltage and phase-to-phase
voltage
D) The ambient temperature and humidity conditions
Answer: C
Rationale: OSHA 1910.269 Table 1 establishes minimum approach
distances based on both the phase-to-phase voltage and the maximum
anticipated transient overvoltage. This is a critical safety consideration
because transient overvoltages can significantly increase the risk of arc
flash and shock. Option A is incorrect because phase-to-ground alone is
insufficient. Option B omits the transient overvoltage factor, which is
essential for determining safe distances. Option D is incorrect as
environmental conditions are not primary determinants of MAD.
QUESTION 2
A distribution line crew is replacing a crossarm on a 7.2 kV phase-to-
ground system. The supervisor needs to determine the appropriate MAD.
What should they use as the reference voltage?
,A) 7.2 kV
B) 12.47 kV
C) 14.4 kV
D) 25 kV
Answer: B
Rationale: OSHA 1910.269 Table 1 uses phase-to-phase voltage for
determining minimum approach distances. For a 7.2 kV phase-to-ground
system in a three-phase wye configuration, the phase-to-phase voltage is
7.2 kV × √3 = 12.47 kV. Option A would be incorrect because it represents
the phase-to-ground voltage only. Option C (14.4 kV) and Option D (25 kV)
are arbitrary values not derived from the given system parameters.
QUESTION 3
A utility company is designing a new overhead distribution line through a
residential neighborhood. The line will operate at 34.5 kV phase-to-phase.
According to NESC Table 232-1, what is the required minimum vertical
clearance over a residential street?
A) 15.5 ft
B) 18.5 ft
C) 21.0 ft
D) 24.0 ft
Answer: D
Rationale: NESC Table 232-1 specifies clearance requirements based on
voltage. For voltages between 22 kV and 50 kV over streets and alleys,
the required clearance is 24 ft. Option A (15.5 ft) applies to voltages below
,0-50 kV in some jurisdictions but is not correct for this voltage. Option B
(18.5 ft) is for 0-50 kV in specific situations but not for 34.5 kV. Option C
(21.0 ft) is not specified for this voltage range in the table.
QUESTION 4
A maintenance crew needs to enter a manhole containing de-energized
but unverified electrical equipment. What additional step does OSHA
1910.269 require beyond the lockout/tagout procedure?
A) Atmospheric testing every 15 minutes
B) Verification of the de-energized state before entry
C) Continuous ventilation of the manhole
D) A standby employee with a rescue harness
Answer: B
Rationale: OSHA 1910.269 requires that before employees enter manholes
or vaults containing exposed energized electrical equipment, the
equipment must be de-energized AND verification of the de-energized
state must be completed. Verification is a critical safety step that ensures
the equipment is truly de-energized. Option A relates to confined space
requirements but is not the primary requirement for de-energized
equipment. Option C is a general safety consideration but not the specific
OSHA requirement. Option D is a rescue requirement but not the
verification requirement.
QUESTION 5
A distribution engineer is selecting conductors for a new 69 kV
transmission line in a coastal area with high wind loads. According to
, NESC Table 253-1, which factor must be considered when determining the
appropriate conductor loading?
A) The conductor’s color and visual appearance
B) Ice thickness, wind pressure, and temperature
C) The number of spans between structures
D) The conductor’s age and maintenance history
Answer: B
Rationale: NESC Table 253-1 specifies ice and wind load factors based on
NESC loading districts. These factors consider environmental conditions
including ice thickness, wind pressure, and temperature. Option A is
incorrect because conductor color has no bearing on structural loading.
Option C relates to span configuration but not the loading factors specified
in Table 253-1. Option D is a maintenance consideration, not a design
factor for initial loading calculations.
QUESTION 6
A crew is installing a direct-burial 600 V secondary service cable in a
residential area. What is the minimum depth of cover required by the
NEC?
A) 12 inches
B) 18 inches
C) 24 inches
D) 30 inches
Answer: B
Practice
QUESTION 1
A journeyman electrician is planning to work on a 25 kV overhead
distribution line. According to OSHA 1910.269, what is the PRIMARY factor
that determines the minimum approach distance?
A) The phase-to-ground voltage only
B) The phase-to-phase voltage and the type of work being performed
C) The maximum anticipated transient overvoltage and phase-to-phase
voltage
D) The ambient temperature and humidity conditions
Answer: C
Rationale: OSHA 1910.269 Table 1 establishes minimum approach
distances based on both the phase-to-phase voltage and the maximum
anticipated transient overvoltage. This is a critical safety consideration
because transient overvoltages can significantly increase the risk of arc
flash and shock. Option A is incorrect because phase-to-ground alone is
insufficient. Option B omits the transient overvoltage factor, which is
essential for determining safe distances. Option D is incorrect as
environmental conditions are not primary determinants of MAD.
QUESTION 2
A distribution line crew is replacing a crossarm on a 7.2 kV phase-to-
ground system. The supervisor needs to determine the appropriate MAD.
What should they use as the reference voltage?
,A) 7.2 kV
B) 12.47 kV
C) 14.4 kV
D) 25 kV
Answer: B
Rationale: OSHA 1910.269 Table 1 uses phase-to-phase voltage for
determining minimum approach distances. For a 7.2 kV phase-to-ground
system in a three-phase wye configuration, the phase-to-phase voltage is
7.2 kV × √3 = 12.47 kV. Option A would be incorrect because it represents
the phase-to-ground voltage only. Option C (14.4 kV) and Option D (25 kV)
are arbitrary values not derived from the given system parameters.
QUESTION 3
A utility company is designing a new overhead distribution line through a
residential neighborhood. The line will operate at 34.5 kV phase-to-phase.
According to NESC Table 232-1, what is the required minimum vertical
clearance over a residential street?
A) 15.5 ft
B) 18.5 ft
C) 21.0 ft
D) 24.0 ft
Answer: D
Rationale: NESC Table 232-1 specifies clearance requirements based on
voltage. For voltages between 22 kV and 50 kV over streets and alleys,
the required clearance is 24 ft. Option A (15.5 ft) applies to voltages below
,0-50 kV in some jurisdictions but is not correct for this voltage. Option B
(18.5 ft) is for 0-50 kV in specific situations but not for 34.5 kV. Option C
(21.0 ft) is not specified for this voltage range in the table.
QUESTION 4
A maintenance crew needs to enter a manhole containing de-energized
but unverified electrical equipment. What additional step does OSHA
1910.269 require beyond the lockout/tagout procedure?
A) Atmospheric testing every 15 minutes
B) Verification of the de-energized state before entry
C) Continuous ventilation of the manhole
D) A standby employee with a rescue harness
Answer: B
Rationale: OSHA 1910.269 requires that before employees enter manholes
or vaults containing exposed energized electrical equipment, the
equipment must be de-energized AND verification of the de-energized
state must be completed. Verification is a critical safety step that ensures
the equipment is truly de-energized. Option A relates to confined space
requirements but is not the primary requirement for de-energized
equipment. Option C is a general safety consideration but not the specific
OSHA requirement. Option D is a rescue requirement but not the
verification requirement.
QUESTION 5
A distribution engineer is selecting conductors for a new 69 kV
transmission line in a coastal area with high wind loads. According to
, NESC Table 253-1, which factor must be considered when determining the
appropriate conductor loading?
A) The conductor’s color and visual appearance
B) Ice thickness, wind pressure, and temperature
C) The number of spans between structures
D) The conductor’s age and maintenance history
Answer: B
Rationale: NESC Table 253-1 specifies ice and wind load factors based on
NESC loading districts. These factors consider environmental conditions
including ice thickness, wind pressure, and temperature. Option A is
incorrect because conductor color has no bearing on structural loading.
Option C relates to span configuration but not the loading factors specified
in Table 253-1. Option D is a maintenance consideration, not a design
factor for initial loading calculations.
QUESTION 6
A crew is installing a direct-burial 600 V secondary service cable in a
residential area. What is the minimum depth of cover required by the
NEC?
A) 12 inches
B) 18 inches
C) 24 inches
D) 30 inches
Answer: B
