NFPA® 502

NFPA® 502

National Fire Protection Association
National Fire Protection Association® (NFPA)
Note: Applicable for Road Tunnel Applications

  • 12.1.2 Emergency circuits installed in a road tunnel and ancillary areas shall remain functional for a period of not less than 1 hour for the anticipated fire condition by one of the following methods:

    • (1) Fire-resistive cables shall be approved or listed for no less than 2 hours when tested to time-temperature curve of ASTM E119, Standard test methods for Fire Tests of Building Construction and Materials, in accordance with ANSI/UL 2196, Standard for Fire Test for Circuit Integrity of Fire Resistive Power, Instrumentation, Control and Data Cables, or other approved, recognized standards, as follows:

      • (a) Fire-resistive cables shall be tested as a complete system, in both vertical and horizontal orientations, on conductors, cables, and raceways applicable.

      • (b) Fire-resistive cables intended for installation in a raceway shall be tested in the type of raceway in which they are intended to be installed.

      • (c) Each fire-resistive cable system shall have installation instructions that describe the tested assembly with only the components included in the tested assembly acceptable for installations.

    • (2) Circuits shall be protected by a 2 hour fire barrier system in accordance with UL 1724, Outline of Investigation for Fire Tests for Electrical Circuit Protective Systems. The cable or conductors shall maintain functionality at the operating temperature within the fire barrier system.

  • 12.1.4 The Electrical systems shall maintain ventilation, lighting, communications, drainage, a fixed water-based fire extinguishing system, fire alarm and fire detection, exit signs, traffic control, and others for areas of refuge, exits, and exit routes, under all normal and emergency modes associated with the facility.

NFPA® 502