As territory manager for Pittsburgh-based Alternative Power Sources, delivering turnkey design solutions for end-users is par for the course for Scott Gagliardi. His company provides sales, service, repair, and maintenance of standby power equipment for industrial and commercial clients — so customization is the name of the game. But recently Gagliardi found himself in a tight spot, facing a formidable challenge with one of his industrial end-users when it came to designing some additional switchgear.
In this particular application — a heavy industrial mill — space constraints left limited options for expansion as the existing electrical room was already pretty full. In addition to the small footprint requirement, the customer insisted that the new switchgear offer draw-out capabilities and meet a specific cable configuration request: one conduit entry from the top and two from the bottom.
Not seeing a solution with his current product offering, Gagliardi turned to Eaton Corp., Pittsburgh, for help. Recommending its Cutler-Hammer Metal-Enclosed Front (MEF) Accessible Switchgear, Eaton's new product (main-tie-main arrangement requiring only 120 square feet of floor space) promised space savings of more than 50% over a traditional metal-clad medium-voltage switchgear arrangement, which requires 266 square feet of floor space.
“In this application, the product saved our customer from extending his electrical room to accommodate the additional space requirements necessary for traditional switchgear,” Gagliardi says. “That easily saved the owner between $100,000 and $150,000. It also allowed us to meet a scheduled shutdown deadline that just wouldn't have been possible otherwise.”
In addition to the obvious reduced footprint advantage, the MEF switchgear enables complete front accessibility to cabling and components, allowing the unit to be installed directly against a wall. This makes both cable connections (incoming and outgoing power) as well as all circuit breakers and transformers accessible from the front instead of traditional switchgear's rear entry.
The MEF's self-powering trip unit eliminates the need for an external power source. The switchgear also easily fits in a freight elevator, can ship in a standard freight container, and can be transported using a fork truck or pallet jack, eliminating the need for overhead cranes and additional construction equipment in retrofit applications. The MEF also features maintenance-free hardware that prevents loosening, a unique pull section for cabling that is only 19 inches wide, and standard drawing packages.
Another unique feature is the product's special current transformer that fits over all three phases of the customer cabling compartment. Using vacuum breakers with drawout capability for easy testing and expansion, the integral trip unit eliminates the need for additional current transformers and door-mounted relays.
“We use a special innovative breaker that's about half the weight and size of the traditional vacuum interrupting circuit breaker,” says David Pisano, product manager, medium-voltage distribution at Eaton Corp., Power Distribution and Assemblies Division, Greenwood, S.C. “The integral trip unit is one of the biggest technological innovations the product offers.”
Maintaining that the MEF is the first product of its kind in the marketplace, created out of a unique need to satisfy a certain customer class, Pisano shares part of the product's development strategy. The incoming utility feed to an industrial facility typically features a medium-voltage equipment line, rated from 5kV to 38kV, he explains. This gives end-users two choices. They can use a switch — an economical reduced feature option — or opt for the larger higher performance of a medium-voltage assembly of circuit breakers, voltage transformers, auxiliary equipment, and other accessories to meet their needs. The MEF provides both a cost-effective, high-performance alternative to these two traditional approaches.
“In attempting to achieve space savings, but also wanting higher performance, we ended up having to either meet their needs with a metal-clad assembly or reduce features to obtain the smaller footprint with a switch,” Pisano says, stressing the fact that this model was designed as a gap filler in the company's good, better, best value proposition. “The MEF offers both.”
Anyone interested in learning more about the MEF's features and capabilities can request a copy of an interactive CD-ROM via the company's Web site at www.eatonelectrical.com.
Integral self-powering trip units
Maintenance-free bus connections
Up to 55% footprint reduction
Up to 15kV; up to 40kA; up to 2,000A