All cable tray systems must be seismically restrained, unless the cable tray supports only non-essential electrical services and is suspended less than 400 mm below the structural support. Earthquakes and seismic events can cause severe damage to electrical infrastructure, including cable trays, leading to outages and even safety hazards. My cable trays, which hold and protect cables, also get a hard time during these events. This affects. Suspended systems such as piping, equipment and ductwork need seis-mic braces to keep them from swaying during an earthquake. (both tensile and compression reactions for rigid bracing and compression reactions only for cable bracing). plant safe shutdown earthquakes (1).
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