By Arthur J. Whelan, Director of Marketing & Engineering, Great Lakes Case & Cabinet Co., Inc.
You need a seismic rated telecommunications rack enclosure. You requested proposals from several rack enclosure manufacturers who claim they have the product you need. Upon receipt of each manufacturers proposal, you notice a difference in product description and price. How do you know which enclosure manufacturer is offering the right product for your seismic structural environment? Well, you won’t unless their telecommunications enclosure meets the Telcordia
Technologies GR-63-CORE (formerly Bellcore GR-63) Issue 1, April 1995 or Issue 2, April 2002
Zone 4 seismic standard, certified by an independent seismic testing laboratory, such as,
Garwood Laboratories in Pico Rivera, California or the National Technical Systems Inc., in
Boxborough, Massachusetts.
Unfortunately, there are some manufacturers who would lead a consumer to believe that enclosures that are “seismic rated” under the umbrella of the 1997 UBC (Uniform Building Code) or the 2000 IBC (International Building Code) actually meet the Telcordia (formerly Bellcore) zone 4 test standards, when they do not. The UBC and IBC seismic specifications are analytical calculations only performed by a structural engineer, and do not necessarily test the enclosure itself but instead how the enclosures frame is secured (e.g. brackets, concrete bolts, etc.) to the
“essential” or “non-essential” structure. The Telcordia test replicates an actual seismic event with doors and side panels installed in order to ascertain that the electronic equipment housed within is safe and secure. It also assures that the door latches and locking mechanisms perform their functions as required.
Although they should, consumers interested in purchasing a seismic tested telecommunications enclosure do not often differentiate between the need for one that meets the Telcordia GR-63-
CORE standards, and the less demanding requirements of the UBC or IBC. As such, these consumers find themselves buying the lower cost product, and not necessarily the better performing one. For most manufacturers, meeting the Telcordia standards often requires them to reinforce enclosure frames, panels, and possibly a new lock design, whereas for those rating their enclosures based on the UBC and/or IBC structural calculations, it may only require them to add a reinforced base plate and a simple bracket or two.
The Great Lakes GL720 Zone 4 enclosures have been tested to meet or exceed the Telcordia GR-
63-CORE seismic Zone 4 standard, which requires that each enclosure frame, with doors and side panels installed, be capable of withstanding significant seismic shocks in both essential and nonessential structural environments. On the other hand, the newer UBC 1998 code has an equation that will rate the enclosure. However, this equation can vary greatly, depending on where the enclosure is installed. If it is in an “essential” environment, the number they put in the equation will be greater than a “non-essential” environment. In other words, a manufacturer can state
“UBC Zone 4 Certified”, but that is extremely misleading, since the Zone 4 does not clarify essential or non-essential. This is another reason the Telcordia Technologies Zone 4 test is a more uniform test; there is no variable as to the level, since there is ONE waveform only, no matter where the installation is located.
Don’t be fooled in to thinking that all Seismic Zone 4 rated enclosures are all the same. Instead, make sure that when you specify a Zone 4 enclosure that it has been independently tested to meet the Telcordia GR-63-CORE Standard, and accept no substitutes. Require the meeting of this standard upfront, and proof from the enclosure manufacturer that it does, and you will never again have to be concerned with your IT seismic environment.