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(ROSSLYN, Va.)—The National Electrical Manufacturers Association (NEMA) has published ABP 1-2010 Selective Coordination.

This new white paper, developed by NEMA’s Low-Voltage Distribution Equipment Section, provides guidance to design professional engineers and Authorities Having Jurisdiction (AHJ) on how to comply with the 2008 National Electrical Code (NEC) requirements in articles 620, 700, 701, and 708. The paper specifically addresses compliance with these requirements for low-voltage overcurrent protective devices.

NEC defines selective coordination as “localization of an overcurrent condition to restrict outages to the circuit or equipment affected, accomplished by the choice of overcurrent protective devices and their ratings or settings.”

ABP 1 outlines an organized approach and provides critical information on this complex and often misunderstood requirement. The key elements to a successful design and approval of the installation require the interactions of the user or customer, design professional engineer, and the AHJ. Much of this information has been provided as feedback on what processes have been successfully implemented in the field.

As the 2008 edition of NEC continues to be adopted by more jurisdictions, the value of this information and the techniques employed can provide an improved understanding and awareness of the requirements and how to successfully implement effective solutions. It has become increasingly important to isolate overcurrent conditions to the closest upstream overcurrent protective device to minimize the disruption of power in critical life and health safety systems.

Manufacturers have provided detailed technical information on how to select and verify that the overcurrent protective devices offered in the market can be used to satisfy the requirements of the system specifications and the intent of NEC. This paper provides a wealth of technical information on the steps and methods to understanding the requirements of the electrical system, the interpretation of the AHJ, competing and conflicting requirements, and design guidelines that have been successfully implemented.

ABP 1 may be downloaded at no charge by visiting www.nema.org/stds/abp1.cfm.

NEMA is the association of electrical and medical imaging equipment manufacturers. Founded in 1926 and headquartered near Washington, D.C., its approximately 450 member companies manufacture products used in the generation, transmission and distribution, control, and end use of electricity. These products are used in utility, industrial, commercial, institutional, and residential applications. The association’s Medical Imaging & Technology Alliance (MITA) Division represents manufacturers of cutting-edge medical diagnostic imaging equipment including MRI, CT, x-ray, and ultrasound products. Worldwide sales of NEMA-scope products exceed $120 billion. In addition to its headquarters in Rosslyn, Virginia, NEMA also has offices in Beijing and Mexico City.

Press/Public Relations Contacts:

NEMA Communications Department

Email: communications@nema.org