What is all the Fuss About NEC Article 708?

What Is All The Fuss About NEC Article 708?

Glenn Myres, PE

The 2008 NEC includes a landmark article that has significant impact on the electrical systems of many facilities throughout the United States. Article 708, Critical Operations Power Systems, includes stringent requirements for new or significantly upgraded facilities that are determined to be “critical infrastructure”.

How do you know if your facility is classified as “critical infrastructure”? The NFPA Task Group on Emergency and Standby Power Systems for Homeland Security wrestled with this question as they worked to determine what constitutes a critical operations facility. Simultaneously, the Department of Homeland Security (DHS) developed the National Infrastructure and Key Resources Protection Plan (NIPP), which defined 17 Critical Infrastructure and Key Resource Sections. Included is a broad spectrum of infrastructure which people expect to continue to function despite man-made or natural disasters. A listing of these facilities includes emergency response facilities like fire, police, and hospitals as well as transportation systems and water and wastewater utilities. Also included are more diverse infrastructure, including critical agriculture and food facilities, banking and finance, chemical, commercial, and communications facilities, defense industrial facilities, energy infrastructure, government facilities, information technology facilities, national monuments and icons, nuclear reactors, nuclear material and waste facilities, postal and shipping, and public health and healthcare facilities. All these types of facilities are necessary for today’s society to continue to function in the face of adversity or disaster. A determination of criticality can be made using the evaluation criteria of the NIPP and the 17 supporting Sector Specific Plans (SSP).

Article 708 does not define when a Critical Operations Power System is required, but instead defers to “municipal, state, federal, or other codes, any governmental agency having jurisdiction or by facility engineering documentation establishing the necessity for such a system.”

Ultimately, Code-Making Panel 20 (CMP-20) was convened specifically for the purpose of writing Article 708. CMP-20 consisted of the Task Group plus other technical individuals. CMP-20 members created Proposal 20-1, which defined the electrical system requirements for critical infrastructure. This proposal was originally slated to become Article 585, but later was designated Article 708 shortly before incorporation into the 2008 NEC.

In order to understand Article 708, comprehension of two definitions is important. The first, Critical Operations Power Systems (COPS), is defined as “Power systems for facilities or parts of facilities that require continuous operation for the reasons of public safety, emergency management, national security, or business continuity.” The second, Designated Critical Operations Areas (DCOA), is defined as “Areas within a facility or site designated as requiring critical operations power.”

When a facility or part of a facility is classified as “critical infrastructure” what does Article 708 require? Some of Article 708’s stringent requirements include:

A risk assessment must be performed, and a mitigation strategy must be developed to address defined risks
All COPS feeders must be 1-hour fire rated (minimum), must be separate from non-COPS wiring, and must be physically protected from damage
COPS equipment rooms must be 2-hour fire-rated and must be above the 100 year flood plain
Access to COPS equipment must be limited to qualified personnel only
A second on-site source of power for the DCOA must be capable of operating the DCOA for three days (72 hours). Four acceptable alternatives are listed in Article 708: storage batteries, a generator set, an uninterruptible power supply, or a fuel cell system. Note that a second utility source is not included as an acceptable alternative.
Enhanced requirements for selective overcurrent coordination and ground fault protection
COPS and non-COPS systems must be kept separate, including separate transfer switches, separate conduit systems, etc.

Article 708 also goes farther than the NEC has ever gone before by requiring a commissioning plan, Authority Having Jurisdiction (AHJ) (usually the Electrical Inspector) witnessed initial baseline testing, AHJ witnessed and documented periodic testing, and an on-going documented maintenance program.

Article 708 sets a new higher minimum standard for electrical systems for our country’s critical infrastructure. This truly is a landmark article.

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Glenn Myres has a BSEE and is a registered Professional Engineer in six states. He has 40 years experience in consulting engineering, plant engineering, and plant maintenance. He is currently responsible for the electrical engineering designs created by Malcolm Pirnie in the mid-west and mid-east areas of the United States.

Malcolm Pirnie Inc. is one of the largest consulting firms in the United States concentrating solely on environmental disciplines. With a staff of more than 1,700 engineers, scientists, planners, management consultants, and support personnel, the firm is devoted exclusively to environmental engineering — water and wastewater engineering, solid and hazardous waste management, water and energy efficiency, financial management, and air pollution control — and management consulting to enhance the performance of public and private organizations in meeting their environmental responsibilities. In addition to our corporate headquarters in White Plains, New York, Malcolm Pirnie has more than 50 branch and field offices throughout the United States, providing convenient access to the nation's major population centers.

http://www.pirnie.com/