Principles
of Operation
v
Y
Functional
Circuit Description
to the overcurrent fault
protection
functions. Trip units with
Static
Trip
lll trip
units use microprocessors
to execute
the communicationscapabilitieshaveanadditional microprocessor
numerical
and logic
operations of
the
fault
protection,
meter-
and
memory which
executes the communications, metering,
ing, and communications
functions,
The
protection
micropro-
and extended
protection
functions.
cessor and its
associated memorycircuits
are
totally dedicated
Basic
Overcurrent
Protection
N,4icroprocessor
Current
Sensors
Static
Trip lll nip
Unil
Static
Trip
lll Tripping
System Functional Block Diagram
Basic
Overcurrent
Protection
Microprocessor
Communications & lvleter ng
Microprocessor
External
15V
dc
Breaker
Control
Wiring
Twisted Pair To
Master Device
-
For CP/CPX Models
Static Trip lllC/CP/CPX
Tripping
System Functional Block Diagram
v