Mike Anthony is a senior electrical engineer with the Architectural and Engineering Services, University of Michigan, Ann Arbor, Michigan.  He can be reached at maanthon@umich.edu.

The skies are filling with friends of National Electric Code (NEC) now that 2005 NEC  Handbook has been published by the National Fire Protection Association. A new “ Flash Protection” industry has been spawned around a single paragraph in Article 110.16, and an up-to-the moment cadre of experts is ready to come to your campus. Electrical professionals throughout higher education may ask for money to meet the flash protection requirement so facility executives should know the basics.

The key idea is that people need to be protected from the hazards of electricity that arise even when you do not touch a live part. A common example of a flash hazard would be plugging in a space heater when the control dial is “ON.” This would cause a flash at the outlet site. Most electrical injuries occur because of flash (an instantaneous ionization of the air around a conducting surface) and not from accidental contact.

Persons within a “ flash protection boundary” need to wear personal protective equipment (PPE)—a so-called “moon suit”—in order to protect themselves from incidental energy (measured in calories per square centimeter). The mathematics that determine the boundary shows up in one of the NEC’s related standards—NFPA 70E, Standard for Electrical Safety in the Workplace. You will find this standard referenced as a fine print note in Article 110.16. All fine print notes in the NEC handbook are offered to users of the code for reference only. Fine print notes are not NEC requirements.

During the writing of the 2005 NEC Handbook, the committee responsible for the flash protection requirement debated whether detailed calculations for the selection of a moon suit ought to be moved from a fine print note into the main body of Article 110.16. The practical effect of this move would have been to require flash protection boundary calculations for every panelboard in every building on every campus in America. By abstaining on a vote to accept the proposal to require these calculations, the APPA code advocacy representative effectively gave the industry (and others) another three years to grasp the implications of, and prepare for, a more rigorous flash protection requirement. Right now the 2005 NEC Handbook only requires marking (with a sign) that a flash hazard exists.

Even this apparently modest requirement has drawn new questions of which the following are typical:

Where do you put the arc flash sign—on the inside or the outside?

It is easy enough to put the mark on free-standing switchgear in a petrochemical plant where few people are at risk. For the uncountable numbers of flush mounted panelboards mounted in, say, public corridors, the NEC is silent. Facility owners may not be so keen to have flash protection signs on flush mounted panelboards on fine architectural walls. Some people believe that the sign itself invites trouble. Recommendation: put a small sign of your own making on the outside and another sign on the inside of the panelboard detailing the PPE required. A second fine print note below Article 110.16 refers to ANSI Z535.4-1998 – Product Safety Signs and Labels as a guide. All the flash protection sign manufacturers will conform to this standard.

Do we need a short circuit study? No. The 2005 NEC Handbook only requires a warning mark. Recommendation: If you decide to exceed the 2005 requirement, a short circuit study may be the least expensive part of determining flash hazard. The costliest part may be in getting accurate as-built circuit diagrams necessary to do the short circuit study. Begin assembling workgroups to verify circuitry within your buildings.

How do we protect our people from flash hazards? Get them personal protective equipment. At the high end, an XX-Large 40 calorie/cm2 outfit with hood, jacket, bib overall, and storage bag runs about $1000. Add to this the cost of gloves and boots. Recommendation: Review your policies regarding who gets near the switchgear required to be labeled. There might be panelboards installed in dormitory corridors where there is student access. You may decide, for example, that qualified electricians should be the only people resetting circuit breakers. Unlike security guards or maintenance personnel, qualified electricians are trained to clear faults before attempting to close breakers again. Reclosing a circuit breaker can cause flash even on a 208/120V panelboard. Article 100 of the NEC suggests that even a 20A breaker would require a moon suit. Discuss with your electricians the degree to which “over-outfitting” electricians with moon suits causes greater hazard when working on smaller panelboards.

Fine minds, when placed around a table, are capable of producing complete nonsense. Our industry, and others, needs more time to prepare for a change of this magnitude. The cost of implementing rigorous flash protection marking is incalculable if you assume that every piece of switchgear in America will require $100 of engineering, material, and labor to meet a requirement for a warning sign as shown on the next page. It is not a matter of “if” but a matter of “when” this requirement becomes part of the NEC codes.

In recent decades the power industry adapted quickly to new information regarding polychlorinated biphenyls (PCBs) and harmonics. While solving one problem, electrical professionals learned about even greater problems (and more promising opportunities) along the way. One immediate consequence of the raised level of debate on flash protection is that at least one manufacturer has discovered a low-cost way to modify the control systems for substation secondary switchgear sections so that flash hazards are reduced by eliminating time delays between circuit breaker action. The impetus for this innovation would not have existed had not the flash protection issue first emerged in the NEC committee meetings.

I look forward to more positive, unintended consequences. Facility executives can make substantial progress in electrical safety by doing the simple things well. Updating circuit diagrams is always a good idea even without a flash protection clause in the NEC. Updating circuit diagrams is drudgery, but the organization that helps its electrical professionals master the drudgery is in the best position to innovate.