Seismic Rated Enclosures FAQ
Transcription
Seismic Rated Enclosures FAQ
Seismic Rated Enclosures FAQ General When should I choose a seismic enclosure over a standard enclosure? A- Choose seismic enclosures for areas that have a high probability of seismic activity. Seismic enclosures may be required by building code or customer specifications. Specifications may reference the NEBS GR-63-CORE document and require a NEBS Zone 3 or Zone 4 enclosure. Does the use of a seismic enclosure guarantee that equipment will not be damaged during an earthquake? A- No. There is no way to predict the result of an earthquake. However, a non-seismic enclosure is not designed to withstand the severe forces that a seismic enclosure is designed to handle. The use of seismic enclosures/kits provide an extra level of defense against seismic damage. For Telcordia GR-63 enclosures, it is an added assurance that an enclosure design has been tested under simulated earthquake conditions. For IBC, it is an added assurance that an enclosure’s concrete anchors have been calculated to withstand seismic loads. The IBC analysis does not include or consider the structural integrity of the rack itself. Does the use of a seismic enclosure eliminate the need to have a licensed professional engineer provide guidance on placement and installation for enclosures? A- No. A full seismic installation involving the placement and bracing of racks, cable runways, etc. can only be designed by a licensed structural engineer familiar with the applicable codes. The IBC kit involves the use of a structural engineer to “certify” the seismic installation has been performed correctly to code. Do seismic racks have a lower load-bearing capacity than non-seismic racks? A- No. The specifications for non-seismic enclosures show the load-bearing capacity for nonseismic conditions, also called the static load. The rack is loaded to assure that the load will not bend the enclosure, but the load is not placed in motion. The specifications for seismic enclosures list the load-bearing capacity for seismic conditions, also called a dynamic load. Although both values are listed as a weight limit, there is a difference. When you compare racks for seismic installations, be sure to compare the seismic (dynamic) load. If you compare racks for non-seismic installations, be sure to compare the non-seismic (static) loads. Most seismic racks will have a higher non-seismic (static) load than a similarly sized non-seismic rack. Is special installation hardware required for internal accessories in a seismic enclosure? A- Yes. All seismic enclosures must be secured to the floor with a special seismic (heavy-duty) anchor. Each anchor has very specific installation requirements for seismic installations. Anchors used for IBC applications must be the anchor shown in the structural calculation packet or have the same tension and shear load ratings. Crenlo | 1600 4th Avenue NW | Rochester, MN 55901 | 507-289-3371 (phone) | 507-287-3405 (fax) | www.crenlo.com Form No.12606.11.09 Why are seismic enclosures more expensive than non-seismic enclosures? A- Seismic enclosures have more engineering design time than non-seismic enclosures and they are also more difficult to manufacture because of the increased welding at tight tolerances. Any necessary independent testing and certification also add to the cost of the enclosures/kits. Why can’t Emcor’s Telcordia cabinet and IBC kits accommodate the use of casters and/or levelers? A- To pass the stringent Telcordia Zone 4 shaker table test, the rack must be firmly anchored to the floor/test bed. Casters and levelers are the weakest area of the assembly and would most likely fail under seismic (dynamic) loads. The IBC brackets are internal brackets and used with a specified frame spacer. The use of casters/levelers would necessitate the use of a different frame spacer or redesign to work properly. Additionally, the calculations will only work with the frame sitting on the floor as the frame’s center-of-gravity would change if casters/levelers are involved. Specifically talking IBC What is the Difference between Essential and Non-essential buildings? A- There are 3 ways a building may be classified essential according to IBC. a. The component is required to function for life-safety purposes after an earthquake. b. Components containing hazardous materials. c. The component is needed for continued operation of the facility or its failure could impair the continued operation of the facility. Every other scenario would be classified as non-essential. Why doesn’t ESQ have a seismic kit? A- ESQ does not have a seismic kit because of its already low static load rating. Additionally, ESQ’s standard use of a pontoon base would necessitate a different design to meet IBC. Where can I find the certification data for these kits? A- On our website. www.crenlo.com/enclosures Where can I get/buy anchors for the seismic kit? A- Anchors may be obtained from Hilti or through their various distributers and sales partners. I have an existing Emcor enclosure, can an IBC seismic kit be retrofitted to it? A- Yes. A seismic installation will require access beneath the enclosure to install the concrete anchorage, so in nearly all cases, the enclosure will need to be briefly unloaded. What is the difference between IBC and UBC? A- UBC (Uniform Building Code) was code maintained by the International Conference of Building Officials (IBCO) used primarily on the west coast of the United States. In an effort to maintain a single set of construction codes, UBC was combined with several other regional building codes to form the International Building Code (IBC). The last revision of UBC was the 1997 version. UBC’s assessed how “bad” the earthquake can be at a particular site by assigning a value of Zone 1 through Zone 4. Starting in the year 2000, the IBC mapped the ground accelerations for the entire USA. Specifying engineers must now reference these ground acceleration values in specifications, not the old UBC Zones. B- The IBC is much more stringent in how it applies the seismic forces to the component’s anchorage resulting in a higher quality seismic installation. Crenlo | 1600 4th Avenue NW | Rochester, MN 55901 | 507-289-3371 (phone) | 507-287-3405 (fax) | www.crenlo.com -2- What does the IBC Map look like? In an effort to simplify the choice of proper anchorage, the seismic map developed by IBC and the USGS was grouped into the designations shown above by our structural engineering consultant. In each region (low,moderate/high) the highest ground acceleration value was chosen to give the most conservative results. Site specific engineering is required near the New Madrid fault and for any floor greater than 50% of the building height. This was done as the loads on the concrete anchors become unacceptably high and site-specific restraints would be necessary to meet code. Who are our seismic competitors and what products do they offer? A- Many enclosure manufacturers offer seismic rated products or tie-down kits, but the verbiage, certification and information is not consistent. a. Middle Atlantic – Has seismic brackets and documentation for each of its vertical enclosures. Documentation claims that the brackets are certified to UBC, CBC, IBC, ASCE and NFPA (certifications vary on enclosure and bracket type). PRODUCT IMAGE: Middle Atlantic’s anchor kit brackets i. Links: 1. Seismic Information Packet: http://www.middleatlantic.com/pdf/wpseis.pdf Crenlo | 1600 4th Avenue NW | Rochester, MN 55901 | 507-289-3371 (phone) | 507-287-3405 (fax) | www.crenlo.com -3- b. Great Lakes - Offers a Seismic Anchor Kit and a “Seismic Zone 4 Enclosure” that complies to GR-63-CORE at 1,000 lb. seismic weight capacity. The Seismic Anchor Kit complies to 2003 and 2006 IBC. PRODUCT IMAGES: Great Lake Seismic Zone 4 Enclosure c. Seismic Anchor Kit i. Links: 1. Great Lake Seismic Zone 4 Enclosure: http://www.werackyourworld.com/pdf/Spotlights/Seismic_Enclosure.pdf 2. Great Lakes Seismic Anchor Kit: http://www.werackyourworld.com/international/products/accessories/cast ers-and-levelers/seismic-anchor-kits/ APC – Offers a seismic option of their NetShelter enclosure as well as Bolt-Down Kit for the NetShelter SX line. The Seismic enclosure is rated to GR-63-CORE and the BoltDown Kit meets 1997 UBC Zone 4 Seismic anchoring requirements. PRODUCT IMAGES: NetShelter VX Seismic Enclosure NetShelter SX Bolt-Down Kit i. Links: 1. NetShelter VX Seismic Enclosure: http://www.apc.com/products/resource/include/techspec_index.cfm?base _sku=AR2144BLK 2. NetShelter SX Bolt-Down Kit: http://www.apc.com/products/resource/include/techspec_index.cfm?base _sku=AR7701 Crenlo | 1600 4th Avenue NW | Rochester, MN 55901 | 507-289-3371 (phone) | 507-287-3405 (fax) | www.crenlo.com -4- d. Damac – Offers “Seismic NEBS” (compliant to GR-63-CORE) and “Seismic UBC” enclosure options. PRODUCT IMAGES: Seismic NEBS GR-63 CORE Certified Cabinet Seismic UBC Zone 4 Rated Cabinet i. Links: 1. Seismic NEBS GR-63 CORE Certified Cabinet: http://www.damac.com/catalog/cabinet-systems/seismic-nebs/seismicnebs-gr-63-core-certified-cabinet-78h-42u 2. Seismic UBC Zone 4 Rated Cabinet: http://www.damac.com/catalog/cabinet-systems/seismic-UBC/seismicubc-zone-4-rated-cabinet-78h-42u e. Other competitors with links to their seismic product offering(s): i. Chatsworth: http://www.chatsworth.com/Products/Cabinet-and-EnclosureSystems/Seismic-Protection-Systems/ ii. AMCO: http://www.imsep.com/seismic_features.html iii. Hammond: http://www.hammondmfg.com/C4CabinetSystem.htm iv. Equipto: http://www.equiptoelec.com/seismic.htm v. Optima: http://www.optimaeps.com/M_series.htm vi. Bud: http://www.budind.com/view/Large+Cabinet+Racks/Seismic+Cabinet+Rack vii. APW Mayville: http://www.apwmayville.com/products/category_overview.aspx?categoryID=1048 viii. Hoffman: http://www.hoffmanonline.com/product_catalog/product_detail.aspx?cat_1=34&c at_2=2410&cat_3=99101&catID=102842&itemID=3648&searchFor=seismic cabinets ix. Martin International Enclosures, Inc.: http://www.martinenclosures.com/whats_new.htm x. Electrorack’s Barracuda line meets UBC Zone 4 ratings Crenlo | 1600 4th Avenue NW | Rochester, MN 55901 | 507-289-3371 (phone) | 507-287-3405 (fax) | www.crenlo.com -5-