Type of Events Momentary 3-Phase 2-Phase 1-Phase Number of Events 20 15 15 12 11 10 10 9 9 8 8 6 5 4 3 3 3 3 2 2 1 1 0 0 0 1994 1995 0 1996 1997 Year © 2009 Electric Power Research Institute, Inc. All rights reserved. 0 61 1998 0 1999 0