Consulting-Specifying Engineer - March 2009 - (Page 58) Equipment Lifecycles the building lighting were routed out of the lighting panelboard, into the control panel, and then out to the building’s lighting fixtures. While branch lighting circuit control was achieved, it was at a much higher cost in terms of labor and space. Additionally, such control panels find themselves out of the office at a moment’s notice. Likewise, utility demand response programs are expected to grow over the next five to 10 years, creating an opportunity for building owners to capture significant savings by shedding loads adds cost to an already labor-intensive solution. Design integrity is also an important consideration for consulting engineers. Specifying robust lighting control systems that are both reliable and safe are key concerns. NEC Article 409 requires that control panels housing relays or contactors must be marked with a Short Circuit Current Rating, which must be equal to or greater than the available short circuit current where the equipment is installed. Proper field inspection is necessary to verify compliance of lighting control panels mounted adjacent to lighting panelboards in an electrical room. Alternatively, lighting control panelboards bring branch circuit control and protection into a single motorized circuit breaker. These circuit breakers are UL-listed and carry an amperage interrupting capacity rating that reduces the need for detailed field inspection. To reduce future lifecycle costs for the customer, consulting engineers also must look at long-term maintenance needs. Today’s intelligent lighting control panelboards feature remote setup, maintenance, and monitoring via a building’s local area network or even over the Internet. Instead of hard-wired connections between relays and circuit breakers, as is the case with a control panel mounted The energy savings an intelligent lighting control panelboard generates over its lifespan also creates real bottom-line savings for the building owner and facilitates a return on investment that pays for the equipment many times over. fall under the requirements of Articles 110 and 409 of the National Electrical Code (NEC), which require them to be listed and rated for the available fault currents. Get smart Intelligent lighting control panelboards are a more effective solution than such configurations because of their design integrity, integration, reliability, and control features. The energy savings an intelligent lighting control panelboard generates over its lifespan also creates real bottom-line savings for the building owner and facilitates a return on investment that pays for the equipment many times over. For example, a typical intelligent lighting control panelboard has a payback period of two to three years; over a five- to 10-year span, it will pay for itself three times or more. Additionally, if a lighting control panelboard’s controller is integrated with a building management system, the information it provides can lead to even more energy savings. What’s more, today’s intelligent lighting control panelboards can evolve to meet future energy management needs. For example, due to low energy costs, there was little desire for remote access of a building’s lighting control system 20 years ago, but today remote access is a feature relied upon by many building owners and facility managers who are busier than ever and during peak demand periods. Intelligent lighting control panelboards already possess the capability to be integrated into an energy management system for this purpose. Ultimately, this means a lighting control panelboard can be viewed as an investment in energy management that delivers tangible savings over its lifespan. Minimizing costs Consulting engineers strive to minimize their customers’ equipment lifecycle costs, which include an electrical contractor’s labor costs, as much as possible. Obviously, a lighting panelboard with an adjacent control panel will take up at least twice as much space as an intelligent panelboard in a crowded electrical room, but installation costs Today’s intelligent lighting control panelboards feature remote setup, maintenance, and monitoring via a building’s local area network or even over the Internet. also are higher in such a configuration. Electrical contractors typically budget about 45 minutes per circuit to add a relay in series with the branch circuit breaker. An eight-circuit lighting control panel would require about six hours to install—the same time it would take to install an intelligent lighting control panelboard. A 42-circuit lighting control panel would take more than 31 manhours to complete and introduces many more opportunities for mistakes, which adjacent to a lighting panelboard, intelligent lighting control panelboards may be reconfigured via programming changes without the need for costly wiring modifications. While reconfiguring a lighting control panelboard may be done remotely by facility personnel, physically rewiring an adjacent control panel will require an electrical contractor and often involve shutdown of the equipment. Additionally, because some intelligent lighting control panelboards feature remote access 58 Consulting-Specifying Engineer • MARCH 2009
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