More than ever, today’s electrical systems are one of the most important part of any office building, industrial plant, hospital or other facility. A major blackout cannot be tolerated. For this reason, selective coordination is critical, and required by the NEC®, for some installations. The following address Code requirements for selective coordination and other related areas.
Here is a checklist for assuring compalince with 2014 NFPA, National Electrical Code requirements for selwective coordiantion found in articles 620, 645, 695, 700, 701, 708 and "coordination" per article 517.
Visit this web page for details on this online design tool that greatly simplifies the selective coordination design process, including coordination between fuses and upstream Eaton circuit breakers.
Selective coordination enforcement
An article from the July-August 2010 issue of the IAEI NEWS covers selective coordination enforcement and overcurrent protective device basics. This article was written by Tim Crnko, Manager, Eaton's Bussmann Division Training and Technical Services.
Selective coordination increases reliability
The 2005 and 2008 National Electrical Code (NEC®) expanded the mandatory requirements for overcurrent protective device selective coordination to include power circuits supplying vital life-safety loads and national security/public safety power systems.
This article by Tim Crnko, Manager, Training and Technical Services provides insight into the need for selective coordination.
Why selective coordination is mandatory
National Electrical Code requirements for selective coordination are mandatory for certain electrical systems where maximum reliability of power is critical. The materials included in this section provide insight into the relationship between selective coordination, system reliability and life safety. The reasoning for why selective coordination is mandatory.
Understanding selective coordination
This excerpt from Bussmann Division's 2008 SPD covers basic and advanced topics related to system coordination. Information is presented as an aid to understanding selective coordination of overcurrent protective devices.
Selective coordination articles
Articles on Selective Coordination including third party articles published in IAEI News and the necdigest provide important insight into the requirements and design of selectively coordinated systems, and the electrical systems where they are required.
- IAEI News July/Aug. 2010 - "Selective Coordination Enforcement: Overcurrent Protective Device Basics"
- IAEI News Nov. /Dec. 2007 - Selective Coordination: Responsibilities for the AHJ
- necdigest December 2007 - Keep the Power on for Vital Loads
Selective coordination code requirements
The 2008 edition of the NEC® includes selective coordination requirements for Elevator Circuits, Emergency Systems, Legally Required Standby Systems, and Health Care Facilities found in the 2005 NEC® as well as additional requirements for Critical Operations Power Systems (COPS). Detailed information on these systems and the 2008 Code requirements can be found in this document.
- 2008 NEC® Coordination Requirements
- Selective Coordination Checklist
- 2005 NEC® Coordination Updates
- NEC® 240.12 System Coordination
- NEC® 517.17 Selectivity - health care facilities requirements for ground fault protection
- NEC® 620.62 Elevator Coordination
- NEC® 700.16 Emergency Lights
Quik-Spec Coordination Panelboard (QSCP)
The Bussmann series Quik-Spec™ Coordination Panelboard was designed specifically to meet the various code requirements for selective coordination in a fully fused system.
Available with up to 400 Amps for a 600Vac or less system with up to 200kA SCCR, this panelboard features ampacity rejecting branch circuit disconnects up to 100amps.
Fuse to fuse and fuse to circuit breaker coordination ratios
This application note contains tested fuse and circuit breaker combinations that deliver selective coordiation between downstream Bussmann series fuses and upstream Bussmann series fues and Eaton circuit breakers.
2008 NEC® coordination updates
The 2008 edition of the NEC® contains all the requirements from 2005 with additional stipulations for Critical Operations Power Systems (COPS). This document covers all the relevant Code sections and how to comply with all 2008 Selective Coordination requirements.
Selective coordination and system reliability
This article addresses the role of the overcurrent protective device in system reliability.
Sample coordination study
A coordination study requires considering many electrical system components. This sample study covers fuses, transformers, conductors and others.