GE IAC User Manual

GEK
-
86054
TIME
OVERCURRENT
RELAYS
TYPES
:
IAC
66
A
,
IAC
66
B
,
IAC
66
C
DESCRIPTION
a
long
time
induction
overcurrent
unit
,
an
The
relays
contain
three
units
:
instantaneous
overcurrent
unit
,
and
a
target
and
seal
-
in
unit
.
APPLICATION
The
IAC
66
A
,
B
,
and
C
relays
are
used
to
protect
a
motor
against
two
abnormal
conditions
.
The
time
induction
overcurrent
unit
(
51
/
TOC
)
protects
against
motor
overloads
.
The
unit
has
a
long
-
time
inverse
characteristic
which
is
designed
to
coordinate
with
the
motor
heating
characteristic
,
coordination
to
insure
against
false
tripping
on
motor
starting
currents
,
and
yet
still
provide
adequate
protection
against
motor
overloads
.
The
usual
setting
for
pickup
is
125
to
150
%
of
the
motor
rating
.
The
instantaneous
overcurrent
unit
(
50
/
I
0
C
-
A
)
provides
fault
protection
,
pickup
of
this
unit
must
be
set
higher
than
the
maximum
momentary
motor
inrush
current
,
with
an
adequate
margin
,
such
as
50
%
or
more
.
Typical
pickup
settings
for
the
two
overcurrent
units
are
as
below
:
Application
requires
The
TABLE
I
PICKUP
SETTING
(
MULTIPLES
OF
MOTOR
FULL
LOAD
CURRENT
)
UNIT
1.15
to
1.4
51
/
TOC
Time
overcurrent
unit
Normal
Dropout
Instanta
-
neous
Overcurrent
Unit
8
to
15
50
/
I
0
C
-
A
The
IAC
66
C
relay
is
similar
to
the
IAC
66
A
and
IAC
66
B
relays
except
that
the
time
unit
and
instantaneous
unit
contacts
are
brought
out
separately
.
These
instructions
do
not
purport
to
cover
all
details
or
variations
in
equipment
nor
provide
for
every
possible
contingency
to
be
met
in
connection
with
installation
,
operation
or
maintenance
.
Should
further
information
be
desired
or
should
particular
problems
arise
which
are
not
covered
sufficiently
for
the
purchaser
’
s
purposes
,
the
matter
should
be
referred
to
the
General
Electric
Company
.
To
the
extent
required
the
products
described
herein
meet
applicable
ANSI
,
IEEE
and
N E M A
standards
;
but
no
such
assurance
is
given
with
respect
to
local
codes
and
ordinances
because
they
vary
greatly
.
3
Courtesy of NationalSwitchgear.com

GE IAC Specifications

General

Brand	GE
Model	IAC
Category	Relays
Language	English