Aluminium alloy can reduce the force on cable trays during an earthquake. (1) Seismic Connectors: I use seismic connectors, like seismic hangers and locking parts (buckles/latches). These make the cable tray connections. This article will explore the importance of seismic resistance in cable trays, discuss when seismic braces are necessary, and help you understand how to make informed decisions for your installation. For over 60 years, the mechanical, electrical, and fire protection trades have relied on TOLCO seismic bracing solutions. Why is seismic bracing important? International Building Code. The cable tray system represented a large distributed mass that was supported between the top of the equipment cabinets and the roof framing. Seismic restraints, on the other hand, are normally spaced considerably further apart with the spacing varying by restraint type, restraint pacity, conduit size, and the seismic design load.