Bridge Expansion Joint for Bridges with Expansion Joints in Lighting Systems

Bridges with integrated lighting systems require expansion joints that maintain the electrical continuity of the lighting circuit while accommodating the movement of the bridge deck. The joint design must provide a flexible electrical connection that can withstand the repeated movement without fatigue failure. Flexible conduit connections at expansion joints allow the electrical cables to move with the bridge deck while maintaining the electrical continuity. The flexible conduit must be long enough to accommodate the full movement range without being pulled taut. The conduit must be waterproof to prevent water infiltration into the electrical system. Cable loop design for expansion joints uses a loop of cable that is long enough to accommodate the full movement range. The loop is installed in a protective conduit that prevents mechanical damage. The cable must be rated for the outdoor environment and must be flexible enough to withstand repeated bending without fatigue failure. Waterproofing at the conduit penetrations through the joint must prevent water from infiltrating the electrical system. Waterproof conduit fittings are used at the penetration locations. The fittings must be compatible with the conduit material and must maintain their waterproofing performance throughout the movement range. Grounding continuity at expansion joints must be maintained to ensure the safety of the lighting system. The grounding conductor must be connected across the joint using a flexible jumper cable. The jumper cable must be rated for the outdoor environment and must be long enough to accommodate the full movement range. Maintenance of lighting system expansion joints requires annual inspection of the flexible conduit connections, the cable loops, and the waterproof fittings. Any damage to the conduit or the cable must be repaired promptly to maintain the safety and reliability of the lighting system.