Specifications of seismic-resistant cable tray tie rods

Seismic-resistant cable tray tie rods are designed to secure cable trays during earthquakes, with specific load ratings, materials, and installation methods to comply with building codes and ensure system integrity.Key SpecificationsMaterial and Construction: Seismic tie rods are typically made from high-strength, zinc-coated steel or pre-stretched wire rope/cable assemblies to provide both tensile strength and flexibility under seismic loads . Pre-stretching allows the tie rod to act elastically, absorbing seismic energy like a shock absorber . Load Ratings and Safety Factors: Tie rods are rated based on minimum breaking strength and allowable load, often with a safety factor of 1.5. Standard sizes include:12 mm (Red) – 900 lbs breaking strength, 600 lbs allowable load18 mm (White) – 1650 lbs breaking strength, 1100 lbs allowable load36 mm (Blue) – 4000 lbs breaking strength, 2667 lbs allowable load48 mm (Yellow) – 6600 lbs breaking strength, 4400 lbs allowable load Components: A typical seismic tie rod assembly includes:Wire Rope/Cable™ – the main tensile elementStake Eye End – factory-attached for anchoring to the building structureOval Sleeve – secures the cable loop through the restraint clipUniversal Restraint Clip (URC) – connects the tie rod to the cable tray support member Installation Guidelines:Tie rods are installed in 4-way sway brace configurations to resist multi-directional seismic forces .Hardware for connecting the tie rod to the building structure (e.g., 3/8” or 1/2” bolts) is selected based on the tie rod size and load rating .Pre-approved assembly drawings and engineering services are available for systems like Eaton's B-Line series with TOLCO seismic bracing, ensuring compliance with IBC, ASCE, and local seismic codes . Design Considerations:Tie rod placement depends on cable tray load, tray span, and seismic zone .Critical systems (hospitals, data centers, emergency power) require higher seismic resistance and may use multiple tie rods per tray section .Engineering calculations should consider dynamic seismic forces, tray weight, and cable load to determine the number and size of tie rods . Compliance and Certification:Systems are often UL listed and comply with model building codes .Certificates of minimum breaking strength are provided with each shipment to ensure quality and code compliance .Engineering services can provide PE-stamped designs for all U.S. states and Canada . By following these specifications, seismic-resistant cable tray tie rods ensure that electrical infrastructure remains secure during seismic events, minimizing damage and maintaining operational continuity.