Case history of a mill-wide project for NFPA 70E compliance and arc flash hazard mitigation

This paper provides a comprehensive account of a mill-wide project to bring a thirty-plus year old market pulp mill into compliance with NFPA 70E requirements and to mitigate arc flash hazards to levels reasonable to allow effective maintenance. The project spanned three years and was completed in 2011. The major activities to be discussed (and through which the project had to progress) include decision to initiate, data collection or re-creation and update of single line diagrams, creation of database and software model, short circuit analysis, multiple upgrades or replacements to address overdutied equipment, arc flash analysis, protection/co-ordination changes to address let-through energy, equipment upgrades or replacements to address let-through energy and mitigate arc flash hazards and, finally, equipment labeling and training of personnel.