Why Does the NEC Prohibit Overcurrent Device Installation in Clothes Closets?

February’s “Code Question of the Month” column addressed overcurrent device installation in clothes closets. The questions were: (1) May service equipment (overcurrent devices in a panelboard) be installed in a walk-in clothes closet? (2) May panelboards in apartments or condominiums be installed in clothes/walk-in closets? The author, Charles M. Trout, was correct in his response that installing overcurrent devices in clothes closets violates section 240-24(d). I must, however, strongly disagree with his opinion that overcurrent devices should be permitted in clothes closets. Clearance issue. If a panelboard were to be installed in an average clothes closet, it must be centered in front of the door so that, with the door open and the closet empty, the installation could meet the minimum workspace clearances per 110-26. With the door open into the living space, the 3-foot requirement should easily be met. Also, a minimum width of 30 inches of working space directly in front of the panel is required. The average clothes closet has a door opening of less than 30 inches. Walk-in clothes closets may be addressed differently. Walk-in closets in large custom homes, which represent the minority of dwelling unit closets, will certainly seem large enough to contain a panelboard (overcurrent devices) and provide storage. However, Code Making Panel 10 (CMP-10) recognized that, “There is no way to control how this space would be used since it has been designed for storage, even in a large custom home.” Homeowners will make use of every square foot of storage space in every closet. Closet organizers of the metal cage type, cardboard boxes, toys, and shoe racks fit quite neatly in that space in front of the gray box left empty by the builder. Accessibility to overcurrent devices must also be considered. Removal of hanging clothes, boxes, decorations, toys, shoe racks, and other household items to gain access does not meet the definition of “readily accessible.” Closets in dwelling units of all sizes of homes are subject to a singular rule. The larger and the more closet space(s) in a dwelling unit, the more boxes, clothes, Christmas decorations, toys, and household supplies we find stored. A local firefighter can verify that closets in most dwelling units are filled to capacity. Location of overcurrent device. Overcurrent devices provide three types of protection. • Overload protection for any current that exceeds the device’s rating. This is the only function that the architect, occupant, and average installer envision ever taking place within a panelboard. • Ground fault protection. • Short-circuit protection, which can be in the tens of thousands of amperes. A short circuit near the interrupting rating of a circuit breaker can cause the circuit breaker to vent. An overcurrent device subjected to a short circuit in excess of the interrupting rating of the device may result in an explosion with a tremendous arc flash. Both situations can result in a fire within the panelboard and in any easily ignitable material in the vicinity. Panelboard trims and covers are, in many cases, left open or off completely in dwelling units. While any location in a dwelling unit could result in a fire in the above-described scenario, the most logical approach is to prohibit such devices from being installed in areas, which will most certainly contain “easily ignitable material.” Lower impedance ratios on utility transformers and larger services of shorter length in today’s new homes are providing for higher levels of available short circuit current at the service equipment. Builders, architects, and homeowners have no idea of the dangers involved. It is our responsibility as electrical contractors, inspectors, and CMP members to provide the safest, most practical installations possible, through proper application of the National Electrical Code (NEC). Removal of the words “such as clothes closets,” which is provided as an example for “easily ignitable material,” would send a message to the builders of America that placing service equipment and panelboards in clothes closets is permitted. This is a safety-driven requirement. There is far more to consider when choosing the location of overcurrent devices than “locations, which are aesthetically acceptable to architects or occupants.” Architects must take into account all applicable codes and standards and provide adequate space for all electrical and mechanical equipment. All homeowners are transient, and will forever argue with builders and electrical contractors over rules, which they perceive as being without merit. This rule is good code, because it is practical, easy to read, and enforceable. • Practical: The NEC is making it clear that it is unacceptable to locate overcurrent devices in the vicinity of easily ignitable material, such as in clothes closets. • Easy to read: The user of this code is given an example of a space, which is considered to contain “easily ignitable material.” • Enforceable: The present text of 240-24(d) provides the authority having jurisdiction and the electrical inspector with clear language to enforce this safety-driven requirement. DOLLARD, chairman of Code Making Panel 10 and Code instructor at IBEW Local 98 in Philadelphia, can be reached at jimdollard98@aol.com.

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