GE AKR-75 Series - Fuse Rollout Elements; Table 4 Fuse Rollout Elements

GEr-86151
B
FUSE ROLLOUT
ELEMENTS
When
the
system
available short
circuit current
exceeds
the rating
of an
AKR-75 or
-100
breaker,
current
limiting
fuses
can
be used in series
with
the breaker
to increase
the
short
circuit rating of the combination.
When used, such
fuses
are
housed in
a separate
drawout compartment
located adjacent
to the breaker compartment; they are mounted
on
a
drawout
carriage similar
to a breaker frame and
referred to as a fuse
rollout element
(FRO).
A typical model
is
shown
in Fig.
6.
As listed in Table
4,
these FRO's are available
in four
drawout styles, each employing the same
type
drawout
mechanism
as
its
companion breaker.
The FRO is racked
into and
out of
its
compartment
just
like
a breaker.
However,
the
fuse
and breaker compartments each are equipped
with
keylocks to
prevent
racking the FRO when
its
associated
breaker
is closed.
All FRO models except the AKD
type feature
a
hinged,
oerforated
steel
screen
in front of the fuses. This
panel
can
*"S
be opened to allow access to the fuses
only
when the FRO is
in the WITHDRAWN
oosition.
In all other
oositions an
inter-
ference
angle attached
to
its left
side
prevents
the
panel
from
being opened.
Unlike the other three types, AKD fuse
rollouts do
not
employ
a screen
in front
of the fuses. lnstead
of acting
directly
on the
racking
mechanism,
the keylock is arranged to
prevent
inadvertent
opening of the
compartment door. So
long
as the breaker is
closed, the FRO
compartment
door
cannot
be opened. lf the breaker is
open, the key
can be
removed
and inserted in
the FRO
compartment lock; the
FRO
compartment door then
can be opened
and the element
racked
at will.
Operation
of
the
breakercompartment
keylock is
the same
for
all models. With
the breaker
open,
the key
can
be
re-
moved; this
extends the lock
bolt, thereby maintaining
the
breaker
in a trip free
state while in
the CONNECTED
oosi-
tion.
The
breaker can be racked
at will reoardless
of the
keylock
position.
TABLE 4 FUSE ROLLOUT ELEMENTS
-
600VAc. 50/60
Hz.
11
4.
t
,$
tr..
$ $
i\:
{,t
"x
tt.'.
',
'
\.-i:.J
\$$
Fig.
6 Fuse
rollout
element TAK94FCA (AKD-S,
6 type)