Why implementing Article 708 as it exists in the 2011 NEC at an existing facility will be very difficult and expensive
It shouldn’t be news to those who keep up with the NEC that Art. 708 [Critical Operation Power Systems (COPS)] was added to the Code in the 2008 edition. What may be news to some, however, is that in the 2008 proposal stage, chemical plants, refineries, oil terminals, or any other facility where a failure or outage may affect the nation’s economy or security, was included in the scope of Art. 708.
Applying Art. 708 to industrial installations, such as refineries and petrochemical plants, is especially difficult, because the flavor of the written text is obviously centered around buildings. It’s a bit like the proverbial square peg fitting into a round hole. There is obviously much work to be done on Art. 708 if it is to apply to industrial locations. But since we now have Code requirements — and we know they’re supposed to apply to these critical locations — we must try to use the rules as they exist today, until something better eventually evolves.
The first term that is essential to become familiar with is a Designated Critical Operations Areas (DCOAs). They’re defined in 708.2 as, “Areas within a facility or site designated as requiring critical power.” Parts, if not all, of an operating facility can be DCOAs. As such, they will need to comply with Art. 708. When confronted with these new requirements, a few questions come to mind:
1) Who will enforce these rules?
2) Who will pay for it?
3) Is Art. 708 applicable to existing facilities?
Unfortunately, the answer to the first question isn’t clear yet. The Department of Homeland Security (DHS) was an integral part of the proposal that placed Art. 708 in the Code; therefore, it would be logical to assume that the DHS will be able to enforce the NEC — much like OSHA does with NFPA 70E. As of press time, it wasn’t known if the DHS has enforced Art. 708 in the United States, particularly in industrial locations.
As for who will foot the bill for what could be millions or possibly hundreds of millions of dollars in expenses, one can only assume that the plant owner will get the honor. As with anything else though, if this rule starts to be enforced on a large scale, there will probably be enough push back from the industry to enact tax incentives or rebates from the government to compensate the owners for at least some of their cash outlay. How this part of the equation plays out is anyone’s guess. But the real key to controlling the cost will be determining what the DCOA consists of. Once the authority having jurisdiction (AHJ) determines what the DCOA consists of, risk assessments can be done, mitigation planning can begin, and plans can be made for program management.
To address the third question, the Code is typically not retroactive unless a major change is made to the electrical system. In cases where major revisions are made, the AHJ typically enforces the latest Code adopted by the jurisdiction. If the DHS is in fact the AHJ, presumably it would have the authority to make existing facilities bring their electrical installations up to Code and possibly meet Art. 708 requirements.
The intent of Art. 708 is to protect the electrical and electrical control systems in an industrial plant from hazards — either man-made or natural. As these disasters must be properly managed, NFPA 1600, “Standard on Disaster/Emergency Management and Business Continuity Plans” should also be consulted. NFPA 1600 lists the minimum requirements for a documented disaster management program. NFPA 1600 is certainly a focal point of Art. 708, but there are other NFPA standards that may be applicable as well, such as NFPA 110, “Standard for Emergency Standby Power Systems” and NFPA 730, “Guide for Premises Security.”
Currently, Art. 708 does not allow the use of cable trays, cable bus, or bus duct. The Code allows feeders to be installed in rigid metal conduit, intermediate metal conduit, or type MI cable. It also allows some types of PVC conduit to be installed, as well as electrical metallic tubing and some types of flexible tubing. Feeders must be protected from fire in a listed electrical circuit protective system for a period of at least 2 hr. If that isn’t possible, the other choices are to protect the circuit with a listed fire-rated assembly that has a minimum rating of 2 hr, or encase the raceways in a minimum of 2 in. of concrete.
As hard as it may be to meet the circuit protection requirements for feeders, consider this — a DCOA must be protected against downtime with an alternative power system. The alternate power source must be able to operate the COPS for a minimum of 72 hr at full load with a steady-state voltage of ±10% of nominal utilization voltage. For a small plant that may have a load of 300MVA, for example, that equates to an enormous amount of generating capacity. By the time one considers the affected industrial plant will have no cable tray, no cable bus, no bus duct, etc. — combined with all of the other requirements that Art. 708 imposes — it actually may become uneconomic to continue business at the
existing plant. It may also inhibit the building of new plants in the United States.
It is my opinion that Art. 708 needs to have major modifications made to it to allow U.S. businesses to be competitive while maintaining adequate levels of security and reliability. The intent of Art. 708 is to provide a more robust, hardened, and well-protected electrical system. As with most rules in the Code, however, it is a work in progress. There is no doubt over the years Art. 708 will continue to evolve.
Trying to implement Art. 708 as it exists in the 2011 NEC at an existing facility will be very difficult and expensive. It remains to be seen who will enforce these requirements and when it will begin. However, since the Department of Homeland Security was an integral part in it being placed in the Code, it’s probably not a matter of ifthese requirements will be used but when.
Guidry is a principal technical specialist for Fluor Enterprises, Inc. in Sugar Land, Texas. He can be reached at email@example.com.