What is Coordination
put it simply, coordination means that downstream devices
(breakers/fuses) should activate before upstream devices. This
minimizes the portion of the system effected by a fault or other
disturbance. At the substation level, feeder breakers should trip before
the main. Likewise, downstream panel breakers should trip before the
substation feeder supplying the panel
Who should go
for coordination study
If you've ever had a breaker trip for a fault that
should have been cleared by a downstream device, your facility would
benefit from a coordination study.
Many breakers have adjustable trip
units. Do you know where yours are set, and why? If the answer's no, a
Coordination Study is overdue
Why Coordination Study ?
To avoid nuisance tripping a
coordination study is a great solution
reduce unnecessary downtime!
recommended settings for
adjustable trip circuit breakers and relays.
Helps increase coordination (
selectivity) between devices. Identifies deficiencies in system
protection. Provides recommended solutions to help correct problem
discusses the use of system devices with respect to National Electric
Code requirements, and appropriate ANSI/IEEE standards.