How to design track busway systems for power distribution in facilities
Industrial power distribution must adapt to new circumstances, and track busways combine performance, functionality and flexibility along with adherence to key industry standards
Whether designing a new industrial facility or retrofitting an existing one, safety, sustainability and functionality are always key factors. Building on those factors, it’s important to take into consideration the need for flexibility to allow the facility to be reconfigured and scaled as production and operational needs change in the future.
One area that hasn’t traditionally been as flexible as it should be is power distribution throughout the facility. Often, power is distributed via busduct or “pipe and wire,” which are not versatile options, especially for a facility that will face future layout and equipment changes.
Track busways, innovated in the 1980s, present an excellent alternative that offers design versatility along with operational reliability and future flexibility when installed. Track busways provide the same high-performance power delivery as traditional pipe and wire systems to meet the demands of the facility while also providing for future scalability and flexibility for power load changes once the facility is in operation.
In a recent survey conducted by Starline, 84% of industrial facilities represented will make at least one significant change to their layouts every 6-12 months. Although track busways are commonly specified and installed in data centers, they offer significant advantages for many industrial and similar facilities including all kinds of manufacturing, distribution centers, indoor agriculture, laboratories, transportation centers and more.
What is track busway?
Open-channel track busway systems are modular, consisting of a U-shaped aluminum shell with copper or aluminum bus bars mounted along the interior wall with a continuous access slot or “open channel,” which runs along the bottom for inserting plug-in units. Track busway systems can be laid out to suit the facility’s needs, using various combinations of straight, elbow and tee sections.
Straight sections are the main busways that deliver power to equipment, workstations or other areas within the facility. Standard lengths for these are typically 5, 10 or 20 feet. Elbows are used to join two straight sections with a horizontal 90-degree turn on a busway run. Tee sections can connect three straight sections in a 90-degree branch leg on a busway run. Finally, power feed units, which are typically placed at the beginning of a busway, run to supply power from the panel board or other source.
Plug-in units integrate circuit breakers and the electrical outlets that supply power to various locations throughout the facility, such as to workstations on a factory floor. The upper paddle of the plug-in unit is inserted into the open channel in the bottom of the track busway, then the unit is turned to lock into place and connect the electrical busbars, which are mounted inside the busway section. Equipment can be plugged directly into the unit or drop cords run from the unit to the equipment.
Proper busway design considerations
To specify track busway correctly for facilities, there are several considerations that must be considered. Chief among them are safety considerations and performance optimization. The motto “safety first” will inevitably be spoken at some point in most any facility where track busway is specified and for good reason. Those working in industrial facilities will have increased exposure to risk simply due to the nature of their work, but the power distribution systems in their environments do not need to contribute to that risk. The elements of a busways system should guarantee safety for employees, equipment and the facility itself.
There are two important aspects to consider:
Load capacity and electrical requirements: Feeding into both the safety considerations and the need for optimal performance, the first step in specifying a track busway system is to understand the electrical load demands of the building. The designs needed for power distribution systems in industrial facilities are often unique compared to other facilities. Primary mechanical systems may run on higher voltage systems than production equipment and base building needs may have even lower voltage needs.
When it comes to the track busway, all of the necessary components in a complete electrical distribution system are incorporated into the plug-in units such as breakers, connectors, power outlets, metering, surge protection and more. The point of these units in industrial facilities is to bring the power sources to the machines and other equipment that will be operated, rather than having to run power all the way back to the source inside of a distant panel.
Track busways can deliver power of 40-1,200 amps, up to 600 volts alternating current (Vac) or V direct current (dc). However, the most common use in manufacturing is 100-225 amp busways. Depending on the length and power rating needed within the facility, a single busway section could support multiple plug-in units that can each support multiple power cords to deliver electricity to myriad equipment or workstations throughout the facility.
Installation flexibility and space considerations: Industrial facilities often feature expansive spaces and likely offer plenty of room for power distribution systems, but when you add in sprinkler systems, ventilation, air or water lines and a variety of other utility needs depending on the facility, the linear configuration and simplified runs of track busway become more attractive.
Track busways offer efficient use of space with lightweight, compact profile sizes and the flexibility of tees and elbows to create limitless multidirectional overhead power grids. Busway systems are not hard-wired to ceilings or walls, enabling a facility to be purpose-built but with all the flexibility its power system needs for future configuration changes when it is in full operation. In Figure 1, the traditional pipe and wire installation is shown next to a busway installation, clearly showing that track busway offers more space to configure other systems for the facility in a straightforward manner.
Codes and standards
When specifying power distribution for industrial facilities, codes and standards compliance is a top priority. Industrial facilities will often have Ingress Protection, National Electrical Manufacturers Association, International Electrotechnical Commission and CSA Group (formerly Canadian Standards Association) standards that apply to them. These vary based on how the facility will operate and what kind of internal environment it will have. There are general industrial standards to understand along with busway-specific standards to consider when specifying track busway systems in a facility.
Although not an exhaustive list, a few of the codes and standards to understand include:
IP ratings: Ingress protection (IP) ratings were developed by the IEC and are a universal system that identifies the environmental conditions in which certain electrical or mechanical components, equipment or systems can be used. The first number in an IP rating is the level to which the system is protected against ingress from solids such as dust, other particles or even probes. The second number in an IP rating is the level to which the system is protected against ingress from water or liquids.
Two common IP ratings required for power distribution systems in industrial facilities are IP54 and IP44. IP44 means there is protection against access from probes as small as 1.0 millimeter and protection against water splashed in all directions. IP54 means that there is limited ingress of dust permitted by the system and it is protected against splashing from all directions with limited ingress permitted.
Industrial facilities often have more dust in their environments that can cause problems in power distribution systems if it collects inside the components. This necessitates a system that can keep dust and larger particle debris out. Depending on the functions of the facility, there may also be liquid splashing or spraying within the environment, so the busway must be able to keep that liquid out. These facilities are also all subject to standards that require sprinkler systems, which mandates splash- or sprinkler-proof power distribution.
Because the environments requiring IP44- and IP54-rated products are quite similar, IP54-rated products are increasingly being specified for both requirements because they comply with the highest standards for the environment where they will be installed.
NEMA ratings: For industrial environments, equipment enclosure standards are also important to understand. NEMA defines the standards that are used across North America. NEMA ratings that begin with 3, 4 or 6 mean that the enclosure is suitable for outdoor use. NEMA 3R-rated enclosures are weather-resistant and protect against falling dirt and precipitation such as rain. When it comes to power distribution systems like track busways, the NEMA 3R rating reinforces the splashproof capability indicated by an IP44 or IP54 designation.
IEC 61439-1 and IEC 61439-6: The IEC standard 61439 outlines definitions, service conditions, construction requirements, technical characteristics and verification requirements for low-voltage switchgear and control gear assemblies. This internationally recognized standard is broken down into multiple sections. This focuses on part 1 and part 6 of the standard, relevant to track busway specification.
Part 1, or IEC 61439-1, simply outlines the general requirements for switchgear, energy distribution, control and switching equipment. Certification to this IEC standard is a baseline need for power distribution systems. Part 6, or IEC 61439-6, outlines the specific standards that busway systems (or busways) must meet. Most busway systems produced for these environments have been designed to these standards, and engineers should make sure that the systems they specify comply with both Part 1 and Part 6 of IEC 61439.
UL 857 and CSA C22.2 No 27: UL 857 and the CSA 22.2 No 27 both apply to the service-entrance, feeder and branch-circuit busways as well as fittings rated 600 or lower voltage or 6,000 or lower amperage. This certification complies with a variety of other standards including the Canadian Electrical Code, Part 1 (CE Code, Part 1), NFPA 70: National Electrical Code and the Mexican Standard for Electrical Installations NOM-001-SEDE, covering myriad international standards for safety.
Specifying track busway systems with either or both UL 857 and CSA 22.2 No 27 certifications, specifically for facilities in North America, can provide confidence that they have been tested to the included standards by independent laboratories.
Chicago Electrical Code: Although electrical codes vary from city to city, the Chicago Electrical Code is known to be one of the more stringent codes. Article 368 of this code specifies requirements and installation for busways.
One provision in this code specifies that busways are not to be installed in rooms or areas where automatic sprinkler systems are installed, because, when activated, it would cause water to come into contact with the busway. The exception outlined in the code is if the busway is listed as weatherproof or raintight. Busways with the IP ratings outlined above would classify as exceptions, permitting them to be installed in areas with automatic sprinkler systems.
Integrating busways with existing building systems
In addition to distributing power to manufacturing machines, workstations or other industrial equipment, track busways can prove a valuable and flexible resource to be specified for other building systems including bringing power for lighting, security cameras, speakers, monitors, data-related equipment or really anything that may have an unexpected load.
Power monitoring capabilities built into the plug-in units will also serve the facilities well in the future, with data on voltage, amps, power factor and other key metrics available to enable smarter energy usage decisions. This information is invaluable for facilities to meet sustainability goals and other environmental initiatives. Plug-in units that can integrate with building management systems are ideal for reliable performance and load balancing.
Industrial facilities continue to grow in complexity as technology and practices advance. Designing for this requires the ability to set the facility operator up for success in the future with built-in flexibility and intelligence, while also focusing on safety and sustainability. One way to meet those advances with power distribution in these facilities is to use systems that can streamline, simplify and scale like track busway. Collaborating with all the players involved including the electrical contractors and system manufacturers can lead to success.