The 2012 International Building Code (IBC) specifies the requirements for a Switchboard to have passed the Siesmic Test requirements. These Siesmic tests are also generally done according to the standard IEEE Std. 344-1987 Recommended Practice for Seismic Qualification of Class 1E Equipment for Nuclear Power Generating Stations.
The seismic test are carried out with accelerations up to 0.9 g in X, Y and Z directions using 2 swinging tables: horizontal table (X, Y directions) and vertical table (Z direction).
In all three test directions the Enclosure should meet the demands of the earthquake test without problems. After this test no mechanical damage should be found such as tears, loose screws or lasting deformations.
Proper mounting of the equipment is the single most important factor in withstanding a seismic event. The mounting surface must be designed to withstand the reaction loads imposed on it by the equipment during a seismic event.
During the seismic vibrations power contacts, cables & wire connections, internal components of switchgear & other devices may get misaligned. This could lead to malfunctioning of the equipment post-earthquake. A study of seismic effects on a structure, equipment or device will reveal its worthiness to withstand an earthquake without appreciable damage and perform satisfactorily during and after sudden shocks and vibrations. It is possible to study their performancethrough prescribed seismic withstand tests. MODUTEC enclosures with certain accessories, are Siesmic Test compliant in design.