Akr-54-30 Breaker With Sst Trip Device - GE AKR Series Maintenance Manual Supplement

Power Circuit Breokers,
GEI-86134
a
1..
:"
,*"ii
rl
I
i
1.
Flux shift
Trip
Device
2. Allen-head
Screws
3.
Stud Connector
4.
Current
Sensor
5.
Tap
Terminal
Board
6.
Programmer Unit
7.
Clamp
Bolt
8.
Sensor
Stud
Fig.
17.
AKR-54-30 breaker with
SST
trip
deuice
Application
of
the
Grorurd
Fault
element on 4-
wire
systems
with neutral grounded
at
the trans-
former requires
an
additional, separately mounted
sensor
(Fig.
19)
inserted in the neutral conductor;
its
secondary
is
connected
to a
fourth primary
winding
on the ground differential tralsformer.
See
Fig.
2?.
This "fourth-wire" neutral
sensor
is
an
electrical duplicate of the phase
sensor, includ-
ing
taps.
Therefore,
when
taps are
changed
on the
phase sensors, those on the neutral sensor must
be
correspondingly positioned.
FIux Shift
Trip
Device
-
a
low-energy, electro-
m@n
receipt of a
trip
signal
from
the programmer
unit, trips
the breaker
by
actuating the
trip
sha-tt.
See
Fig.
22.
All
components except the neutral sensor are
mounted on
the
circuitbreaker.
The phase sensors
are located
on
the
breaker's
back
frame.
The
pro-
grammer unit
and
the flux shift trip
device are
mounted on
the
breaker's front frame.
These com-
ponents
are interconnected by
wiring
harness
and
disconnect
plugs, as
shown on
the cabling diagrams
(Figs.
25 and 26).
When used,
the neutral
sensor
is
separately
mounted
in
the bus
or
cable compartment
of
the
switchgear.
In drawout construction,
its
output is
automatically
corurected
to
the
breaker
via
second-
ary
disconnect
blocks.
See
Fig.
20.
15