Long a staple in many a doomsday scenario, earthquakes traveling all along the Richter scale can easily leave a trail of massive destruction in their wake. While the intensity and number of temblors needed to dramatically affect the existence of life on this planet remains impossible to calculate much less predict, much has been accomplished in recent years in terms of preparedness for seismic events, especially within the world of systems integration.
Vital to the function of public and private facilities alike, systems integration frequently provides communication links imperative to life safety. For this reason and others, a stringent set of building codes governing system construction within areas prone to seismic activity and for essential facilities everywhere has evolved that are designed to meet the needs of protecting building occupants on a number of levels.
At the core of any system lie its central components-the head-end gear that resides in rackmount enclosures. While it is equally important to insure that flown loudspeaker arrays and other system elements can withstand the sometimes violent shrugging of Mother Nature's shoulders, equipment enclosures have a responsibility to both remain standing and keep the vital equipment stored inside operational so that system functions may continue when they are needed most.
Designed to insure just this, the seismic certification required of most building codes for equipment racks and cabinets falls into two categories, the first of which addresses anchorage provisions. In a most basic sense, anchorage provisions are designed to meet life safety requirements for protecting building occupants from the dangers of racks and cabinets falling over or obstructing exit areas during a seismic event. This type of certification is required by the UBC (Uniform Building Code), CBC (California Building Code) and IBC (International Building Code) for installations in moderate to high seismic regions of the country.
The second main category of seismic certification pertaining to racks and cabinets deals with anchorage and cabinet structure that meets life safety requirements like those just mentioned, as well as those for "Essential Facilities" where the survival and operability of critical equipment following a seismic event is required. This more demanding certification is mandated by the IBC for installations in regions exposed to moderate or high seismic risk or those that have an Importance Factor of 1.5. The latter category commonly includes medical, fire, police, telecommunications, and other critical government and institutional facilities.
Completely democratic in the range of its scope, the Importance Factor rating of 1.5 isn't exclusively reserved for high seismic risk areas or "vital" buildings. Any structure, private or otherwise, can "deem" itself to have an Importance Factor of 1.5 if they too want to insure that their rackmount systems remain functioning following a seismic or ground-motion event.
Rather than viewing today's stringent building codes as just another set of bureaucratic regulations, perhaps they should be seen as road maps to building better, safer buildings and supporting infrastructure. Within our industry, protecting rackmount equipment is now easier, thanks to the provisions of these codes and the racks that are certified to meet them. Ganging racks and solid side cabinets may not be as glamorous as the high-tech gear they hold, but they are the first line of defense in keeping a system running when seismic disaster strikes.
Keeping Seismic Simple
With the requirement for seismic-certified enclosures in an increasingly broad array of environments-not simply areas of high seismicity but also institutional, military and life safety installations as well-integrators and consultants require seismic solutions that are as accessible and practical as the enclosures used in everyday applications. Keith Carney, Middle Atlantic Products' vice president of engineering and quality control, explains that there are five simple questions integrators and consultants should consider when presented with a seismic project.
The first consideration is rudimentary. What exactly are the codes required for an enclosure to be seismic-certified? The answer: There are five important codes, and enclosures should be rated to meet all five including Uniform Building Code (UBC) 1997, the International Building Code (IBC) standard of 2000 and 2003, the CBC 2001, and the ASCE 2002 and NFPA 2003 ratings are all relevant. So, when it comes time for the project engineer to sign off on a job, he/she has confidence that the widest array of codes are met.
In addition to considering seismic codes, consultants and project engineers can specify with confidence when they take the Component Importance Factor (Ip) into account. Simply put, this value, typically 1.5, is a safety factor that is commonly specified to provide an extra margin of safety for the installation. It is specified for essential facilities to ensure the rack or enclosure will function after a seismic event.
Once the project is defined and the appropriate enclosure has been identified, the next question is how to acquire it. "The seismic factor should not present a bottleneck," Carney explained. "Integrators should be aware whether a special order is involved. Otherwise, the project may stall, and that can cause expensive delays."
A systems approach means taking into account how seismic certification impacts other elements of the system. The fourth question, then, is whether the enclosure requires special assembly or additional parts and, if so, whether they consume rack space. "It's a simple question, but not one to ask after the system has been designed, since that can cause other issues, especially if all rack space was already accounted for," Carney warned.
The system may require riser bases, as is often the case with large, cable-intensive installations including broadcast and media installations, or security consoles in military or life safety applications. Integrators should question whether these elements are also seismic-certified. "Systems are only as safe as the weakest element," Carney added. "So it's critical that, in raised floor applications, seismic enclosures are mounted on seismic riser-bases. Similarly, security consoles protect essential equipment and the safety of the occupants of that building or area, that in the case of seismic activity, needs to be safeguarded."
Specifying and ordering seismic products does not need to be more complex or expensive than non-seismic products, but special considerations do need to be made early in the project's process. When all of the components meet all of the codes and when ordering is easy, it reduces complexity and potential pitfalls.
Middle Atlantic Products...
P.E. Certification for anchorage and cabinet structure must meet criteria outlined by the 2003 IBC Section 1621. Lowell Manufacturing has a line of UL-listed, seismic racks and cabinets that are P.E.-certified based upon rigorous analysis of factors including maximum spectral acceleration (ground motion), and installed locations (lower, middle or upper third) within a building. All given an "S" suffix to their normal part numbers, the Lowell IBC qualified, seismic essential facility lineup includes ganging racks from the company's L275, L277, L278 and L279 Series, as well as solid side cabinets from the L265, L267 and L268 Series.
All of Lowell's S-suffix ganging racks and solid side cabinets with adjustable rails meeting IBC Essential Facility criteria for both anchorage and cabinet structure include a reinforced base, "X"-style sides for racks, factory-installed EQQ Series braces (if required), and a P.E.-certified document package for IBC anchorage and cabinet structural qualification within essential facilities.
Satisfying the technical, seismic and quality assurance provisions of the 2003 IBC for essential and non-essential facilities with an IBC Importance Factor of 1.5 and spectral acceleration forces up to 3.0 G's, the Lowell document package is unique within the industry. Its comprehensive analysis eliminates the need to hire a structural engineer to perform the time-intensive and laborious seismic calculations normally associated with essential facility installations.
"With the document package in hand, system designers won't have to do seismic calculations for each cabinet and rack location in a building," said Kevin Ditch, the engineering manager at Lowell who hired the outside professional engineering firm that produced and certified the documents that ship with each Lowell IBC seismic essential facility qualified rack and cabinet. "Nor will they have to generate the quality assurance documents required by applicable building officials or other authorities, as each package includes seismic calculations, installation drawings and a quality assurance plan for special inspections."
Seismic-pioneer, Middle Atlantic Products offers a broad array of enclosure systems, riser bases and security consoles certified to meet UBC, CBC, IBC and, importantly, ASCE and NFPA standards. The range includes Middle Atlantic Products' DRK, MRK, ERK, VMRK, VRK, SCRK and SCQRK Series welded vertical enclosures, SC and SCQ Series monitoring consoles and SRB Series Raised Floor Riser Bases which are all seismic-certified standard and do not require rackspace-consuming seismic plates. Beyond product information, Middle Atlantic Products publishes comprehensive technical information on seismic certification requirements and techniques at www.middleatlantic.com/wp/wpseis.htm.