This is compounded by the high variability from site to site, and the extreme weather conditions in some regions. 90 percent of the outages are less than 5 minutes in duration. 99 percent of the outages are less than 1 hour in duration. Total cumulative outage duration is approximately 100 minutes per year. Consider all equipment, all power lines, all data lines, and all connection points.
Short term decreases in voltage levels.
This is the most common power problem, accounting for 87 percent of all power disturbances according to a study by Bell Labs. Utilities also create sags as a means of coping with extraordinary power demands, like high air conditioner use on a steamy summer's day. Sags also reduce the efficiency and life span of electrical equipment, particularly motors. Complete loss of utility power. Loss of utility power means the connected equipment goes down.