Data centers are poised to become the largest power users globally by 2025, consuming one-fifth of the world’s power. As more companies shift critical infrastructure to the cloud and as edge computing drives the growth of multitenant and colocation facilities, the need to provide effective power distribution in these facilities will only continue to grow as well.
These developments will put enormous pressure on data center operators to identify opportunities to save on energy costs and operate a more efficient power infrastructure. Whether it’s multitenant, colocation or another type of facility, data center managers must ensure that power is adequately and efficiently distributed while maintaining worker safety and reducing the overall physical footprint of power-distribution equipment.
Traditionally, data centers have relied on cable and conduit to distribute power, and this approach has worked (and still does work) reasonably well for many facilities. But as data center power demand grows, it’s worth considering what alternative solutions better suit operators’ need for efficiency, safety and maximized physical space. In recent years, it has come to mean looking at busways.
In this article I’ll look at some advantages of busways over traditional power distribution for data centers. I’ll also examine important features to seek out when looking to implement busway in your facility.
What Is Busway?
At the highest level, busway is a highly efficient method for distributing electrical power throughout a facility—particularly when it comes to loading or extending power from an existing distribution system.
Busway comes in various shapes, sizes and forms, but in general, all busway solutions feature the same core elements. First are the conductors, also called busbars, which are solid bars of either copper or aluminum that carry electrical current. Next is the housing: the metal enclosure that contains the conductors. Finally, we have the insulation, the main component that protects against electrical faults by separating conductors from one another and from the unit’s housing. Most busway products feature either air-insulated or epoxy-insulated designs.
Busway comes in two basic styles:
- Feeder busway. Available in a wide variety of configurations, feeder busways are the main elements of a busway system, and they include both straight lengths and fittings such as elbows, tees, and offsets.
- Plug-in busway. Available in straight lengths only, plug-in busways feature the added ability to support one or more bus plugs at fixed positions. Bus plugs allow for power to be tapped off the busway system through an overcurrent device (i.e., breaker/fuse) to easily feed downstream loads.
Busway is especially attractive for data centers, as they house racks full of servers, uninterruptible power supplies (UPSs) and other electrical equipment. Historically, cable and conduit has been the primary way of distributing power to this equipment. They’re often embedded beneath the floor, making moves, additions or changes expensive and time consuming. With busway, supporting new or rearranged systems is as easy as adding more pieces, relocating bus plugs or replacing feeder segments with plug-in sections.
Busway vs. Cable/Conduit: The Benefits
Beyond those already mentioned, the use of busway in lieu of cable/conduit offers multiple advantages:
- Ease of installation. Installing cable and conduit is complex, labor-intensive work that only highly specialized electricians can perform. Busway, by contrast, is a far simpler technology that most electricians with only rudimentary mechanical skills can assemble without expert help (it’s ideal in edge data centers that are typically less well staffed than traditional facilities). Busway assembles quickly with as few as one bolt per connection. Installers can add up to 10 feet of busway at a time compared with routing multiple runs of conduit, and having to go back and pull cable through the pipes.
- Lower implementation cost. Paying specialized electricians for the hours of effort required to bend and route conduit is a costly proposition—one that busway all but eliminates. In fact, many busway manufacturers have total-ownership-cost calculators on their product web pages to help customers determine the financial benefits. Facilities that use busway can divert that cost savings into upgrades and other expenses that truly benefit the business.
- Space savings. Space is always at a premium in power facilities. Busway offers a compact technology relative to cable and conduit that leaves more room for other, potentially revenue-generating uses. For example, a typical 2,000-ampere service could take up 99 square inches with cable and conduit versus less than 38 square inches with busway.
- Cost-effective adaptability. Once cable and conduit are in place, moving, expanding and reconfiguring systems in response to growth or new requirements is both expensive and disruptive to daily operation. With busway, facilities installing new equipment can simply add new bus plugs to their existing busway, while companies that need to move equipment can quickly and easily reconfigure their existing busway or even replace feeder busway with plug-in busway where required. This flexibility allows minimal interruption of service compared with a traditional cable solution.
In all, these benefits can prove highly attractive to data center operators looking to maximize available facility space while reducing capital expenditures, all with a demonstrable benefit that helps improve the businesses’ profitability.
What to Look For in Busways for the Data Center
Now that we’ve established the advantages of busway technology over cable and conduit, let’s consider the features that ensure a solution is right for the data center in question. When looking to capitalize on busway’s considerable benefits, data center owners and operators should seek out products that feature these attributes:
- Certified safety. At the bare minimum, any busway worth using should be certified by UL, the Canadian Standards Association or the International Electrotechnical Commission (IEC). Products that don’t meet these standards haven’t undergone certified testing for safe operation and may pose a risk to the facility implementing them.
- Indoor and outdoor options. Depending on the data center, you’ll likely want busway to serve your needs both inside and outside the facility. Reputable busway manufacturers typically offer options for both, so make sure to seek out those who do.
- Wide variety of current ratings. Varying applications require varying current ratings, which can shift over time as the facility grows and power-distribution needs change. The best busway solutions enable any current rating the facility might need, both now and in the future.
- High fault-current ratings. To protect sensitive electrical equipment such as servers, busway must be capable of handling the available fault-current rating of a given power-distribution system.
- Broad range of plug options. Look for product families whose bus plugs offer breaker, fusible-switch, contactor and starter options for every requirement, as well as multiple surge-protection and metering alternatives.
- Flexible configuration options. Variety is equally important when it comes to power distribution, so choose busway products capable of handling both single- and three-phase power, with or without a neutral bar, or even with a 200-percent neutral option. Selecting products that support integral, internal and isolated grounding options is also critical.
- Ease of installation. All busway products are easier to install than cable and conduit, but best-in-class offerings further simplify deployment by providing thoughtful extras such as alignment pins that prevent operators from installing bus plugs out of rotation as well as clearly labeled stickers that illustrate where segments connect.
- Alternative options for connecting directly to other electrical equipment. Most busway manufacturers require facilities and contractors to connect other products such as group metering and panelboards using cable runs between bus plugs and distribution equipment. The most sophisticated busway solutions, however, save money and floor space while shortening installation times by allowing companies to connect group metering and panelboards directly into a nearby busway segment instead.
- Comprehensive services and support. Finally, although busway is an intuitive and largely do-it-yourself technology, users occasionally require planning and implementation assistance. Make sure to buy only from vendors with the experience and resources to offer expert support and services when needed (e.g., busway-measurement services, final field-fit services and commissioning).
As the need for power in data centers continues to grow, so too will the need for effective and efficient solutions to distribute it while keeping costs low and maximizing physical space. Though cable and conduit has been the default option for distributing power to data center electrical equipment for many years, busway offers an extensive list of practical and financial advantages for operators that can help them offset the growing need for power to serve their facilities.
Data center professionals looking to simplify power distribution and increase agility while reducing costs and conserving space should take a close look at busway solutions that offer the features, support and capabilities to meet their unique and evolving needs.
About the Author
Steve Lovell is the Product Line Manager for Busway—part of the Commercial Distribution Products and Assemblies business, Electrical Systems and Services Group, Electrical Sector—for Eaton. Lovell joined Eaton in 1996 through the Westinghouse Distribution and Control Business Unit acquisition and has held positions of increasing responsibility, including LVA product manager, field project manager, project engineer and division sales engineer. He holds a bachelor’s degree in electrical engineering from North Carolina State University.