National Electrical Safety Code (NESC) Questions

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What is the NESC vertical clearance above a railroad?

NESC Rule 232 covers the "vertical clearances of wires, conductors, cables, and equipment above ground, roadway, rail, or water surfaces." The required clearances above a railroad are shown below.

NESC Clearance Above Ground

Item Cable or Conductor NESC Clearance Comments
A Phase 26.5 ft Applies to phase wires 22kV and below. For voltages above 22kV phase-to-ground, see NESC Rules 232C and 232D.
B Neutral 23.5 ft Applies to neutrals meeting NESC Rule 230E1.
C Secondary 24.0 ft Applies to secondaries 750V or less meeting NESC Rule 230C2 or 230C3 (triplex, quadruplex, etc.).
D Communication 23.5 ft Applies to cable TV, phone, fiber optic cables, etc.

Notes:

  • The owner or operator of the railroad will often require greater clearances than the NESC when permitting the crossing.
  • Clearances shown are required during the temperature and loading conditions detailed in NESC Rule 232A and must be maintained at the worst case clearances at 32°F with ice from the applicable loading zone, 120°F, or greater than 120°F if so designed. Since the NESC requires the clearances to be maintained under specified conditions, a sag chart is required to know if clearance is meets the Code requirements.
  • See NESC Rule 234I for horizontal and diagonal clearances to railroad cars.
  • See NESC Table 232-1 for additional footnotes.






The information presented above attempts to answer common questions about the NESC to help the reader understand the Code. Additional rules may apply and the reader should use this information only as a starting point to aid in reading the Code and investigating the actual Code requirements for the situation under consideration.