Lineman Technical Standards and Specifications 2 — Questions and Answers
Question 1: According to NESC rules, what is the minimum vertical clearance for a 7,200-volt distribution line over a public road?
- 14 feet
- 18 feet
- 22 feet (Correct answer)
- 25 feet
Correct answer: 22 feet
NESC requires a minimum vertical clearance of 22 feet for lines up to 22 kV over public roads.
Question 2: Which ASTM standard governs the specification for wood utility poles?
- ASTM A36
- ASTM F1234
- ASTM D25 (Correct answer)
- ASTM B230
Correct answer: ASTM D25
ASTM D25 is the standard specification for round timber poles used in utility construction.
Question 3: When installing guy wires, NESC specifies that the guy strand must be rated to withstand what percentage of the calculated load?
- 50%
- 75%
- 100%
- 110% (Correct answer)
Correct answer: 110%
NESC requires guy strand to be rated for at least 110% of the calculated load to provide a safety factor.
Question 4: What does the term 'Grade B' construction refer to in the NESC?
- Lines in rural areas with lower load requirements
- Lines meeting standard utility construction practices for general supply (Correct answer)
- Lines in extreme ice-loading zones
- Underground residential distribution systems
Correct answer: Lines meeting standard utility construction practices for general supply
Grade B construction in the NESC refers to standard utility construction practices used for general power supply lines.
Question 5: Per IEEE Standard 524, what is the recommended maximum sag tension ratio for ACSR conductor stringing?
- 15%
- 25% (Correct answer)
- 35%
- 50%
Correct answer: 25%
IEEE 524 recommends that stringing tension not exceed 25% of the conductor's rated breaking strength to prevent damage during installation.
Question 6: In OSHA 29 CFR 1910.269, what is the minimum approach distance for a qualified lineman working on a 12.47 kV (phase-to-phase) energized line?
- 1 foot 5 inches
- 2 feet 2 inches (Correct answer)
- 3 feet 9 inches
- 5 feet 3 inches
Correct answer: 2 feet 2 inches
OSHA 1910.269 specifies a minimum approach distance of 2 feet 2 inches for phase-to-phase voltages from 5.1 kV to 15 kV.
Question 7: What standard class of rubber insulating gloves is required when working on circuits up to 17,000 volts AC?
- Class 0
- Class 1
- Class 2 (Correct answer)
- Class 3
Correct answer: Class 2
Class 2 rubber insulating gloves are rated for use up to 17,000 volts AC (proof-tested to 20,000 volts).
Lineman Technical Standards and Specifications 2
According to NESC rules, what is the minimum vertical clearance for a 7,200-volt distribution line over a public road?