ABB 511 Series - Addend. A,1(p.22)

IB
7.2
.
1.7
-
1
A
Addendum
A
(
Rev
1
)
Page
1
Type
51
Catalog
Series
423
Time
-
Overcurrent
Relays
(
with
Thyristor
Output
)
INTRODUCTION
Type
51
Time
-
Overcurrent
Relays
with
catalog
numbers
starting
with
423
are
similar
to
relays
of
the
223
series
,
but
offer
totally
drawout
construction
with
integral
test
facilities
.
Current
transformer
shorting
is
accomplished
by
a
direct
-
acting
spring
and
blade
assembly
upon
removal
of
the
relay
from
its
case
.
Sequenced
disconnects
eliminate
any
possibility
of
nuisance
tripping
during
withdrawal
or
insertion
of
the
relay
.
Basic
operation
,
external
connections
,
and
electrical
specifications
for
the
423
series
are
the
same
as
for
the
223
series
.
OBSERVE
ALL
PRECAUTIONS
listed
in
the
basic
instruction
book
,
IB
7.2
.
1.7
-
1
A
,
page
2
.
Precaution
#
9
as
applicable
to
the
423
series
should
read
:
“
9
.
The
entire
assembly
of
the
overcurrent
relay
is
removable
.
This
assembly
should
insert
smoothly
.
Do
not
use
excessive
force
.
”
CONNECTIONS
Typical
external
connections
are
as
shown
in
Fig
.
1
,
page
6
of
IB
7.2
.
1.7
-
1
A
.
NOTE
that
while
the
same
numbered
connection
points
are
used
in
the
423
series
units
,
their
relative
position
on
the
rear
terminal
block
of
the
relay
is
NOT
the
same
.
See
internal
connection
diagram
shown
below
.
External
test
devices
as
shown
in
Fig
.
3
,
page
17
are
generally
not
required
with
the
423
series
units
.
INTERNAL
CONNECTIONS
:
Type
51
Catalog
Series
423
NOTE
:
User
to
remove
links
LT
or
LI
only
if
external
contact
to
be
used
to
torque
-
control
the
relay
.
Remove
LT
for
control
of
51
element
.
Remove
LI
for
control
of
50
element
.
For
single
phase
units
omit
coil
1
-
2
and
5
-
6
.
For
two
phase
units
omit
coil
3
-
4
.
Courtesy of NationalSwitchgear.com