APC BK600EI Power Supply User Manual


 
Page 17
Utility voltage sags are temporary amplitude reductions of the normal line voltage level.
Utility voltage sags can be caused by local high power demand equipment such as
elevators, air conditioners, shop tools and electric heaters. Brownouts, defined as long
lasting utility voltage reductions, are sometimes initiated by the power company itself.
During the hot season, the utility may choose to reduce the line voltage in order to cope
with the huge power requirements of home and commercial use air conditioners.
Blackouts are defined by a complete loss of power. Often, blackouts are caused by
accidents or acts of nature. However, they can also be created by overloaded “branch”
circuits (building wiring segregated by fuses or circuit breakers), faulty circuit breakers or
even a tripped-over line cord!