GE IFC53M User manual

INSTRUCTIONS
TIME
OVERCURRENT
RELAY
TYPE
IFC53M
GEK-65572
Supplement
to
GEK-45375
GENERAL
‘1’
ELECTRIC

GEK-65572
TIME
OVERCURRENT
RELAY
TYPE
IFCS3M
I NTRODUCT
ION
These
instructions
are a
supplement
to
instruction
book
GEK-45375.
The combination
of the
two books
form instructions
for
the
Type
IFC53M
relay.
These
relays
provide
for
a
target
seal-in
unit
for
both
the time
overcurrent
element
and the
instan
taneous overcurrent
unit.
The Type
IEC53M
relay
is similar
to
the Type
IFC53A
with
the
addition
of
a
right—hand
target
and
seal-in
unit
and
a
high
dropout
instantaneous
unit
mounted
in
the
rear
of
the
relay
unit.
The special
high dropout
instantaneous
unit
is
constructed
without
a
target
and
is
designed
to yield
dropout values
of 80
percent,
or
higher,
of
pickup
current.
The pole
piece
is
constructed
and
secured
with
a
special
wave
washer
so
that
it
can be
rotated
to the
most
favorable
position.
The
unit
may
be
calibrated
in the
standard
manner
once
the
pole
piece
has been
adjusted
for
80 percent
dropout
or
higher.
HI-SEISMIC
HIGH
DROPOUT INSTANTANEOUS
UNIT
The
high dropout
instantaneous
unit
contacts
will
close
30
amperes
at
voltages
less
than
250
volts.
The coil
ratings available
are
shown
in Table
1.
The
high
dropout instantaneous
unit
is
tapped
for operation
on
either
of
two
ranges
(H or
L).
Selec
tion
of the
high
or low
range
is
accomplished
by
means
of a
range
selection
link
located
on
the
top
of
the
support
structure.
TABLE
1
Tap
Continuous
**One
Second
K
Unit
Position
*Range
Rating Rating
(Pjnps)
(mps)
L
2-4
1.9
2-8
70
4900
H
4-8
3.0
L
4-8
4.3
4-16
140
19600
H
8-16
6.9
L
10-20
9.0
10-40
275
75500
H
20-40
16.2
L
20-40
12.6
20-80
275
75500
H
40-80
20.0
*The
range
is
approximate
which
means
that
the 2—4,
4-C may
be
2-5,
4-8.
There
will
always
be
at
least
one drnpere
overlap
between
the
maximum
L
setting
and
the
minimum
H
setting.
Whenever
possible
select
the
higher
range, since
it
has
the
higher
continuous
rating.
Make
sure
that
the
range
selection
link
is
in
the
correct
position
for
the
range
in
which
it
is
to
operate.
These
2nstructloflq
do not
purport
to cover
all
details
or
variations
in
equipment
nor
to
provide
for
ever;
possible
contingency
to
be
met in
connection
with
installation,
operation
or
maintenance.
Should
farther
information
be
desired
or should
particular
problems
arise
which
are
not covered
sufficiently
for
the
ourchaser’s
purposes,
the
matter
should
be referred
to
the General
Electric
Company.
Tc
the
extent
requirod
the products described
herein
meet
applicable
SI,
IEEE and
NEiL21
standards;
but
no such
assurance
is
given
with respect
to
local
codes
and
ordinances
because
they
vary
greatly.
3

GEK—55572
**Higher
currents
may
be
applied for
shorter lengths
of
time
in
accordance
with
the
formula:
The
high
dropout
unit
coil
is
in
series
with
the
time
overcurrent
unit
coil,
see
Table I,
and
GEK
45375
to
determine
the
current
limiting
element
for
both
continuous
and
short
time
ratings.
The
high
dropout
instantaneous
unit
is
similar to
the
standard instantaneous
unit
except
it
has
no
target,
and
dropout
current
is
approximately
80
-
90
percent
of the
pickup
current.
Fig.
3
Is
a
picture
of
the
high
dropout
unit.
The
adjustable
core
(A)
sets
the
pickup level.
Turning
the
core
down
(clockwise,
top
view)
lowers
the
pickup,
while
turning the
core
up
(counterclockwise,
top
view)
increases
the
pickup.
Before
attempt
ing
to
turn
the
core,
the
locknut
(B)
must
be
loosened.
After
adjusting
the
core,
the locknut
must
be
retightened.
When
loosening
or
tightening
the
locknut,
the
sleeve
(C)
to
which
the
shading
ring
(D)
is
attached
must
be
held to
preveit
it
from
turning.
Rotation
of
the
shading
ring
sets
the
dropout
level
and
thereby
determines
the
quietness
of
operation
in
the
picked
up
position.
The
core
has
been
factory
set
to
obtain
80
percent
dropout
at
the
minimum
setting and
approximately
90
percent
dropout
at
the
maximum set—
tlng.
Should
it
be
necessary
to
change
the
dropout
setting, the
sleeve
(C)
to
which
the
shading ring
CD)
is
attached
must
always
be
turned
in
the
clockwise
direction
(top
view).
This
will
prevent
the
sleeve
and
shading
ring
assembly
from
being
loosened.
The
unit
will
pick
up
at
the
scale-plate
marking
plus
or minus
five
percent
with
gradually
applied
current.
The
operating
time
is
shown
in
Fig.
4.
Fig.
S
shows transient
overreach
characteristics.
The
Hi-Seismic
high
dropout
instantaneous
unit
burdens
are
listed
in
Table
2.
TABLE
2
Hi—Seismic
I
High
Dropout
Movable
Mm.
Burdens at
Mm.
Burdens
in
Ohms
(Z)
Hz
Lead
Pickup
Pickup_(Ohms)
Times_Pickup
Inst.
Unit
Position
Amps
R
Z
3
10
20
(Amps)
L
2-4
2
0.77
0.66
1.02
0.66
0.52 0.52
2-8 60
H
4-8
4
0.26 0.16
0.30
0.23 0.22
0.22
L
2-4
2
0.68
0.56
0.88
0.60
0.48 0.44
2-8
50
H
4—8
4
0.24 0.13 0.27
0.22
0.19
0.19
L
4-8
4
0.22
0.18
0.29 0.18 0.14 0.13
4-16
60
H
8-16
8
0.079
0.030 0.084
0.061
0.056
0.056
L
4-8
4
0.19
0.14
0.024
0.16
0.13
0.12
4-16
50
H
8-16 8
0.069
0.030
0.075
0.056
0.054
0.052
L
10-20
10
0.045
0.027
0.053
0.037
0.032 0.029
10-40
60
H
20-40
20
0.020 0.007 0.021
0.018
0.017
0.017
L
10-20
10
0.039
0.024
0.046 0.032
0.028
0.025
10—40
50
H
20-40 20
0.017 0.006
0.018
0.015
0.014 0.014
L
20-40
20
0.025
0.008
0.027
0.022 0.022
0.021
20-80
60
H
40-80
40 0.018
0.001
O.OU
0.014 0.014
0.013
L
20-40 20
0.021
0.007
0.022
0.018 0.018
0.017
20-80
[50
H
40-80
40
0.015
0.001
O.0l0.O12
0.012
0.011
INSTALLATION
The
outline
and
panel
drilling
diagram
is
shown
in
instruction
book
GEK-45375.
The
internal
connec
tion
diagram
is
shown
in
Fig.
6
of this
supplement.
4

GEK-b5512
TIME
DIAL
SEAL-
IN
TARGET
FOR
TIME
OVERCURRENT
UNIT
E
AL - N
T AROFT
TAP SE[.LCT DR
Fig.
1
(8043607)
TAP
SELECTION
BLOCK
INSTANTANEOUS
UNIT
RANGE SELECTION
LINK
SEAL-IN TARGET
FOR
INSTANTANEOUS
OVERCURRENT
UNIT
SEAL-IN TARGET
TAP SELECTOR
SCREW
Type
IFC53M
Relay,
Renoved
fro
Cise.
Front
‘[lew
N --
5

/
INS IANTANEOUS
HIGH
DROPOUT
UNIT WITH
ADJUSTABLL CORE
-M AG N
El
ASSEMBL’ FOR
TIME
OVERCURREN
UNIT
Fig.
2 (8O436O8
Type
IFC53M
Relay,
Removed
from Case,
Rear View
6

ADiUSABLE
CORE
(A)
LOCKNUT(B)
)tL
E’
—
..‘--
-
—SHADING
RiNG(D
Fi 1 .
.3
8O3b363
Construction
of
the high
Dropout
Instantaneous
Linit
1

GE
K-6 557?
c
030
0.025
o.c20
0.015
0010
o.
005
MULTIPLES OF
PICK—UP
0
LI
U,
LI
D
0
OPERATING TIME
.
RANGE FOR
ANY
—
PICKUP
SETTING
00
1
2
3
4
5 6 7
8
9
10
F-€UbR7-5)
O;erting Ti
e Vrsus Current for the
Hich
Dropout Instantaneous
(int

25
1:
--I
4 .-t
•
1.-f
______
TRANSIENT
0VEN.REACH
HNC
REAY
‘TTT
Ti:ii
TiI
Lfljff.-} 4 _u:.
HtL
TTiJTf
.f1t_H
fmHtT.1-.I-n
-fL:
—
L
PCENT
OV
EAC}1
100
ri H
A=
PICKUP
CURR2T
GRADUALI.Y
APPI
TED.
t
B=
CURRENT
SUDDENLY
APPLIED.
H-
-f
t--
20
f:t
-H-4-1
1.
-
i4E:.
.-.--
-I--.
ft
Vt
ii
JiiT
Ii
T_i
t—+
f- 4
4
I
If
-1-’
1—
-
Ht
.H-ll-
1t
.ZE
1
0.
-3 0)
D
c- -5
-3 0) n
‘
C -h (0 =
C
C C
V 0) 0)
3)
C
C
V
I
WI
llII
•i
I
-4.
-4
Tf
4-z
-
,4.
4
V
H:
1
f.1..’
441+-
tt-f-l
+
i
-H-f-i-!
-*H
4.
-‘4--
-
—
-r-t-t
-:
f
4
4
H-
‘4-.
—
4
-
H
:;
it
i
1--
Tfl1f 4
4H-
Ii
I-
4
;4.-44
4
I
j
..4-_.4._._•,
T
t
•—;--
4,
-
-if-.
±±
f-Vt
-f-
15
.-4
3..
IT
:tf
-tY
—
t•!-f..
E
-h-H*
-1--ftt
4
41
ii
‘-4
-4
jiL:j
-.
1::
TEETTr
L1i
h-t-t-r-t-I--t-t
•
-I
CALm.
ll:Fit:
IT
;!
—ti
(Ir
--f-f’
tfI!II,H.f4-:b
‘-I, 7c
i*t-i.
--H-f
H
i-H-u
MAX.
CALTh.—
-H
4..
•,
.
-
•
4
H-f+
----4----I---1--4---
-1-_-1_
-,-j--i-,-
4-.
I—+-,--j-H-—-
4 -tfl-
-
I
—s--’
-‘-$A
H
-
-±tt------f
T
t__+
t
—4-,
-I-I-’
It
-[f-i
r:lo
+11-
fZZl44
4-
1-4
-
1--1-+
ii
F
.1_I
;4...
. 1 -f
1 oH-
‘
20
LI4
—I-
:1W:
I--’
4-
—
:1±1
30
tttfii
140
-
±LLtLHffFJJ
-
t-
14
5-i
I’
4-1-
ItT
---H
60
‘:•
50
j-4NGLE
IN
DrREES
LAG.
L
I
I
I1fI
I I
I
1fIiTTtTTTi
±Vt-
-+
‘-f-rj--I--
-
—
:r
tIT
-+
-
t---
-—:-
1—
‘i:i
-I
---44.--,-.-
go
-
—
‘_11j,4
J 17 O ztt
rEdil
4 :$1tfl
fl4$:
ill
11111
111111:11,

GEK-65572
LNSTANTANEOUS
HI DROPOUT
N
= SHORT
FINGER
Fig. 6 (o275A4554-a)
Internal
Connection Diagram
for
Type
IFC53M
Relays
INDUCT
ION
SI
*
*
2
(0
10

GE
Power
Management
215
Anderson
Avenue
Markham,
Ontario
Canada L6E
1B3
Tel: (905)
294-6222
Fax:
(905)
201-2098
www.ge.comlindsyslpm

GEK—45375J
TIME
OVERCURRENT RELAYS
Types
IFC51A
and
51B
IFC53A
and
53B
IFCJ7A
and
778
INSTRUCTIONS
GE
Protection
and
Control
205
Great
Valley
Parkway
Malvern,
PA
19355-1337

GEK-45375
CO
N TENTS
DESCRIPTION
3
APPLICATION
3
CONSTRUCTION
5
RATINGS
6
TIME
OVERCURRENT
UNIT
6
HIGH-SEISMIC
INSTANTANEOUS
UNIT
7
HIGH-SEISMIC
TARGET
AND
SEAL-IN
UNIT
8
CONTACTS
8
BURDENS
9
CHARACTERISTICS
10
TIME
OVERCURRENT
UNIT 10
HIGH-SEISMIC
INSTANTANEOUS
UNIT
10
HIGH-SEISMIC
TARGET
AND
SEAL-IN
UNIT 10
RECEIVING,
HANDLING
AND
STORAGE
10
ACCEPTANCE
TESTS
11
VISUAL
INSPECTION
11
MECHANICAL
INSPECTION
H
DRAWOUT
RELAY
TESTING
12
GENERAL
POWER
REQUIREMENTS
12
TIME
OVERCURRENT
UNIT
12
HIGH-SEISMIC
INSTANTANEOUS
UNIT
13
HIGH-SEISMIC
TARGET
AND
SEAL-IN
UNIT
14
INSTALLATION
15
INSTALLATION
TESTS
15
PERIODIC
CHECKS
AND
ROUTINE
MAINTENANCE
16
TIME OVERCURRENT
UNIT
16
HIGH-SEISMIC
INSTANTANEOUS
UNIT
16
HIGH-SEISMIC
TARGET
AND
SEAL-IN
UNIT
16
CONTACT
CLEANING
16
COVER
CLEANING
17
SYSTEM
TEST
17
SERVICING
17
TIME
OVERCURRENT
UNIT
17
HIGH-SEISMIC
INSTANTANEOUS
UNIT
19
HIGH-SEISMIC
TARGET
AND
SEAL-IN
UNIT 19
RENEWAL
PARTS
20
LIST OF
FIGURES
40
—2-

GE
K-
45375
TIE
OVERCURRENT RELAYS
TYPES
IFC51A
and 518
IFC43A
and
53B
IFC77A
and
778
DESCRI
PTION
The
type
IFC
relays
covered
by
these
instructions
are
extended
range,
single
phase,
time
overcurrent
relays.
The
various
time-current
characteristics
available
are
as
follows:
IFC51A,
IFC51B
— Inverse
time
IFC53A,
1FC538
— Very
inverse
time
IFC77A,
IFC77B
-
Extremely
inverse
time
The
IFC51B,
538
and
778 relays
also include
a
hinged-armature
instantaneous
overcurrent
unit,
which
provides
instantaneous
tripping at
high
current
levels.
The
instantaneous
unit
is
not
included
in
the
IFC51A,
53A
or
77A
relays. Both the time
overcurrent
unit
and the
instantaneous
overcurrent
unit
are described
in
detail
in
the
section
on
CONSTRUCTION.
Each
relay
is
equipped
with
a
dual-rated
target
and
seal-in
unit.
When
semi
flush
mounted
on
a
suitable
panel, these
relays
have
a high
seismic
capability,
including
both
the
target
seal-in
unit
and the
instantaneous
overcurrent
unit
when
it
is
supplied.
Also,
these
relays
are
recognized
under
the
Components
Program
of
Underwriters
Laboratories,
Inc.
The
relay
is mounted
in
a
size
Cl
drawout
case
of
molded
construction.
The
outline
and
panel
drilling
are shown
in Figures
23
and
24.
The
relay
internal
connections are
shown
in
Figure
4
for
the IFC51A,
53A and
77A, and
in
Figure
5
for
the IFC51B,
53B and
77B.
APPLICATION
Time
overcurrent
relays
are
used
extensively
for
the
protection
of
utility
and
industrial
power
distribution
systems
and frequently
for
overload
backup
protection at
other
locations.
The
EXTREMELY
INVERSE
time
charactersistics,
Figures
10
and
22, of
the
IFC77A
and
77B
relays
are designed
primarily
for use
where
they
are required to
coordinate
rather closely
with
power
fuses,
distribution
cutouts
and
reclosers.
They
also
provide
maximum
tolerance
to
allow
for
cold load
pickup
such
as
results
from
an extended
service
outage,
which
results
in
a
heavy
accumulation
of
loads
of
automatically
controlled
devices
such
as refrigerators,
water
heaters,
water
pumps,
oil
burners,
etc.
Such
load
accumulations
often
produce
inrush
currents
considerably
in
excess
of
feeder
full
load
current
for
a
short
time
after
the
feeder
is
energized.
These
instructions
do not
purport
to
cover
all
details
or
variations
in
equipnt
flat
to provide
for
every possible
continqenry
to
be
met
jn connection
with
installation.
operation
or
wsintananCe
Should
further
information
be
desired
or should
particular problee’
arise
which
are
not
covered
sufficientl
for
the purchasers
purposes,
the
matter
should be
referred
to
the
General
Electric
CoaflY.
Do
the
extent
required
the
products
described
herein
meet
applicable
ANSI,
IEEE
and
NE
standards,
but
no such
assurance
is
given
with respect
to local
codes
and
ordinances
because
thei
vary gr.atly.
-3—

GEK—45375
The
EXTREMELY
INVERSE
time
characteristic
often
permits
successful
pickup
of
these loads
and
at
the
same
time
provides
adequate
fault
protection.
The
VERY
INVERSE
time
characteristics,
Figures
7
and
21,
of
the
IFC53A
and
53B
relays
are
likely
to
provide
faster
overall
protection
in
applications
where
the
available
fault
current
magnitude
remains
fairly
constant
due
to
a
relatively
constant
generating
capacity.
The
variation
in
the
magnitude
of
fault
current
through
the
relay
is therefore
mainly dependent
upon
the
location
of
the
fault
with
respect
to
the
relay.
The
INVERSE
time
overcurrent
characteristics,
Figures
6
and
20,
of
the IFC51A
and 513
relays
tend
to
make
the
relay
operating
time
less
dependent
upon
the
magnitude
of
the
fault
current
than
in
the
case of
VERY
INVERSE
and
EXTREMELY
INVERSE
devices.
For
this
reason,
INVERSE
type
relays
are
likely
to provide
faster
overall
protection
in
applications
where
the
available
fault
current
magnitudes vary
significantly
as
a
result
of frequent
changes
in
the
source
impedance
due
to
system
loading
and
switching.
The
usual
application
of
these
relays
requires
three relays
for
multiphase
fault
protection,
one
per
phase,
and
a
separate
relay
residually
connected
for
single—phase-to—ground
faults.
Typical
external
connections
for this
appli
cation
are
shown
in
Figure
9.
Use
of
a
separate
ground
relay
is
advantageous
because
it
can
be
set
to
provide
more
sensitive
protection against
ground
fa
u 1
t
s.
In
the
application
of
these
relays
with
downstream
automatic
reclosing
devices,
the
relay
reset
time
should
be
considered.
This
is
the
time
required
for
the
relay
to
go from
the
contacts—fully-closed
position
to
the
fully—open
position
when
set
at
the
number
10 time
dial.
At
lower
time
dial
settings
the
reset
times
are
proportionately
lower.
The
reset
time
of
all
VERY INVERSE
and
EXTREMELY
INVERSE
relays
is
approximately
60
seconds.
The
reset
time
of
all
INVERSE
relays
covered
by
these
instructions
is approximately
12
seconds.
When
setting
these
relays
to
coordinate
with
downstream
relays,
a
coordination
time
of
from
0.25
to 0.40
seconds
is
generally
allowed,
depending
on
the
clearing
time
of
the
breaker
involved
and
how
accurately
the
relay
time
can be
estimated.
These
coordination
times
include,
in
addition
to
breaker
clearing
time,
0.10
seconds
for
relay
overtravel
and
0.17
seconds
for
safety
factor.
For
example,
if
the
breaker
clearing
time
is
0.13
seconds
(8
cycles),
the
coordination
time
would
be 0.40
seconds
(0.13
+
0.10
+
0.17).
If
the
relay
time
is
set
for
the
specific
current
level
at
the
site,
and
if
it
has been
tested,
the
safety
factor
may
be
reduced
to 0.07
seconds.
Then
if the
downstream
breaker
time
is 5
cycles
(0.08
seconds),
a
minimum
of 0.25
seconds
(0.08
+
0.10
+
0.07)
could
be
allowed
for
coordination.
If
relay
coordination
times
are
marginal
or
impossible
to
obtain,
use the
relay
overtravel
curves
of
Figures
10,
11
or 12
to
refine
the
relay
settings.
First
determine
the
relay
operating
time
necessary
to
just
match
the
operating
time
of
the downstream
relay
with
which
coordination is
desired.
Determine
the
multiple
of
pickup
and
the
necessary
time
dial
setting
to
provide
this
relay
operating
time.
Use
the
appropriate
curve
of
Figure
10,
11
or
12
to
determine
the
overtravel
time
in
percent
of
operating
time,
and
covert
this
into
real
time.
Add this
time
to
the
breaker
time
and
the
safety factor
time
and
the
original relay
operating
time
to
determine the
final
relay
operating
time.
Set the
relay
to
this
value.
—4-

GEK-45375
Once
the current
in
the
relay operating
coil
is
cut
off, the
relay
contacts
will
open
in
approximately
6 cycles
(0.1
second)
with normal
adjustment
of
contact
wipe.
This
permits
the
use
of
the relay
in conjunction
with
instantaneous
reclosing
schemes
without
risk
of
a
false
retrip
when
the
circuit
breaker
is reclosed
on a circuit
from
which
a fault
has just
been
cleared.
The
instantaneous
overcurrent unit
present
in
the
IFC51B,
53B
and 77B relays
has a
transient
overeach
characteristic
as illustrated
in
Figure
13.
This
is
the result
of
the
DC
offset
that
is usually
present
in the
line
current
at
the
inception
of a fault.
When
determining
the
pickup
setting
for
this unit,
the
transient
overreach
must be
taken
into consideration.
The
percent
transient
overreach
should
be applied
to
increase
the
calculated
pickup
setting
proportionately
so
that
the instantaneous
unit will
not
overreach
a
downstream
device
and
thereby
cause
a
loss
of
coordination
in
the system
protection
scheme.
The
operating
time
characteristics
of
this
unit are
shown
in Figure
14.
CONSTRUCTION
The
IFC
induction
disk
relays
consist
of
a
molded
case,
cover,
support
structure
assembly,
and
a
connection
plug
to
make
up
the
electrical
connection.
See
Cover
Figure
and
Figures
1,
2, 3 and
19.
Figures
2
and 3
show
the induction
unit
mounted
to
the
molded
support
structure.
This disk is
activated
by
a
current—operating
coil mounted
on either
a laminated
EE-
or
a
i-Magnet.
The
disk
and shaft
assembly
carries
a
moving
contact,
which
completes
the alarm
or trip
circuit
when
it touches
a
stationary
contact.
The
disk
assembly
is restrained
by a
spiral
spring
to give
the
proper
contact
closing
current.
Its
rotation
is
retarded
by a
permanent
magnet
mounted in
a
molded
housing
on
the
support
structure.
The
drawout
connection/test
system
for
the Cl
case,
shown
in Figure
19,
has
provisions
for
14
connection
points,
and
a visible
CT
shorting
bar located
up
front.
As
the connection
plug
is
withdrawn,
it
clears
the
shorter
contact
fingers
in
the
output
contact
circuits
first.
Thus,
the trip
circuit
is
opened
before
any
other
circuits
are
disconnected.
Next,
current
circuit
fingers
on
the case
connection
block
engage
the
shorting
bar
(located
at
the
lower
front
of
the
case)
to short-circuit
external
current
transformer
secondary
connections.
The
window
provides
visual
confirmation
of CT
shorting.
The
connection
plug
then clears
the
current
circuit
contact
fingers
on
the
case and
finally
those
on
the
relay
support
structure,
to
de-energize
the
drawout
element
completely.
There
is
a High-Seismic
target
and
seal-in
unit mounted
on
the
front
to the
left
of
the
shaft
of the
time
overcurrent
unit
(see
Figure
1).
The
seal—in
unit
has its
coil
in
series
and
its
contacts
in parallel
with
the contacts
of
the time
overcurrent
unit,
such
that when
the induction
unit
contacts
close,
the
seal—in
unit
picks
up
and
seals in.
When
the
seal—in
unit picks
up,
it
raises
a
target into
view,
which latches
up
and
remains exposed
until
released
by
pressing
a reset button
located
on the
upper
left side
of the
cover.
—5—

GEK—45375
The
IFC
‘SB”
model
relays,
in
addition
to
the
above,
contain
a
high-seismic
instantaneous
unit
(see
Figure
1).
The
instantaneous
unit is
a
small
hinged—
type
unit
which is
mounted
on
the
front
to the
right
of
the
shaft
of
the
time
overcurrent
unit.
Its
contacts
are
normally connected
In
parallel
with
the
contacts
of
the
time
overcurrent
unit,
and
its
coil
is
connected
in
series
with
the
time
overcurrent
unit.
When
the
instantaneous
unit
picks
up, it
raises
a
target
which
latches
up
and
remains
exposed
until
it
is
released.
The
same
reset
button
that
releases
the target
seal—in
unit
also
releases
the
target
of
the
instantaneous
unit.
A
magnetic
shield,
depicted
in
Figure
1,
is
mounted
to
the support
structure
of
inverse
and
very
inverse
time
overcurrent
IFC
relays
(IFC51
and
1FC53),
to
eliminate
the proximity
effect
of
external
magnetic
materials.
Both
the
High-Seismic
target
and
seal-in
unit
and
the
High—Seismic
instantaneous
unit
have the
letters
“Hi—G”
molded
into
their
target
blocks
to
distinguish
them
as
High—Seismic
units.
Seismic
Fragility
Level
exceeds
peak
axial
acceleration
of
lOg’s
(4g ZPA)
when
tested
using
a
biaxial
multi—
frequency
input
motion
to
produce
a
Required
Response
Spectrum
(RRS)
in
accordance
with
the
IEEE
Proposed
Guide
for
Seismic
Testing
of
Relays,
P501,
May,
1977.
RAT
I
NGS
The
relays
are
designed
for
operation
in
an
ambient
air
temperature
from
-20°C
to
+55°C.
TIME
OVERCURRENT
UNIT
Ranges
for
the
time overcurrent
unit
are
shown
in Table
I.
TABLE
I
Relay Frequency
(Hertz)
Current
Range (Amperes)
IFC51A
&
B
0.5
-
4.0
IFC53A
&
B
50
and
60
IFC77A
&
B
1.0
-
12.0
The
current
taps
are
selected
with
two sliding
tap
screws
on
an
alphabetically
labeled
tap block.
The
tap screw
settings
are
as
listed
in
Table
II,
on
page 20,
for
each
model
of
relay
and
tap
range.
The
one—second
thermal
ratings
are
listed
in Table
III.
-6-

GEK—45375
TABLE
III
Model
Time
Overcurrent
Unit
One Second
Rating
Any
Tap
K
L
(Amperes)
(Amperes)
IFC51
0.5 - 4.0
128
16384
1.0
- 12.0
260
67600
1FC53
0.5
- 4.0
140
19600
1.0
- 12.0
260
67600
1FC77
0.5 - 4.0
84
7056
1.0 - 12.0
220
48400
Ratings
less
than
one
second
may be
calculated
according
to
the formula
I
JK/T,
where
T is the
time
in
seconds
that
the
current
flows.
The
continuous
ratings
for the
time
overcurrent
unit
are shown
in Tables
IV
and
V.
TABLE
IV
0.5
—
4.0 Ampere
Range
Ratings
Tap
Model
0.5 0.6 0.7
0.8
1.0 1.2
1.5 2.0 2.5 3.0
4.0
4 1FC51
1.6 1.8
2.0
2.1 2.3
2.7 3.0
3.5
4.0 4.5 5.0
1FC53
3.8 4.0 4.2
4.4 4.7 5.0
5.3
5.8
6.2 6.6
7.1
1FC77
2.5 2.7 3.0
3.2
3.6 4.0 4.5
5.2
5.9
6.5 7.5
TABLE V
1.0
- 12.0
Ampere
Range
Ratings
Tap
Model
1.0
1.2
1.5
2.0 2.5
3.0
4.0
5.0
6.0
7.0 8.0
10.0
12.0
IFCS1
3.7
4.1
4.6
5.3
6.0
6.5 7.6 8.5
9.3 10.0
10.8
12.1 13.2
1FC53
6.8
7.1 7.7
8.3 8.8
9.4
10.3
11.0
11.6
12.4
12.6
13.5
14.41
1FC77
5.8 6.4
7.2
8.4
9.4
10.4 12.1
13.6
15.1 16.4
17.6 19.8
21.
HIGH-SEISMIC
INSTANTANEOUS
UNIT
The
instantaneous
coil is
tapped for
operation
on
either
one of two
ranges
(H
or L).
Selection
of the
high or
low
range
is determined
by
the
position
of
the
link
located
on the top
of the
support
structure
(see
Figure
2 and
Table
VI).
-7-

GEK—45375
TABLE
VI
One
High—Seismic
Continuous
Second
Instantaneous
Link
Range
Rating
Rating
Unit
(Amps)
Position
(Amps)
(Amps) (Amps)
K
2
-
50
L
2
-
10
2.7
130
16,900
H
10
-
50
7.5
6
-
150
L
6
30
10.2
260
67,600
H
30
-
150
19.6
The
range
is
approximate,
8-50.
There
will
always
maximum
L
setting
and
the
sure
to
select
the higher
rating.
which
means
that
the 2—10,
10-50
may
be 2-8,
be
at
least
one
ampere
overlap
between
the
minimum
H
setting.
Whenever
possible,
be
range,
since
it
has
the higher
continuous
Higher
currents
may
be
applied
for
shorter
lengths
of
time
in
accordance
with
the formula:
I
=
v’K/T
Since
the
instantaneous
unit
coil
is
in
series
with
the
time
overcurrent
unit
coil,
see Tables
III,
IV,
V
and
VI
to
determine
the
current—limiting
element
for
both
continuous
and
short—time
ratings.
HIGH-SEISMIC
TARGET
AND
SEAL—IN
UNIT
Ratings
for
the target
and
seal-in
unit
are
shown
in
Table
VII.
TABLE
VII
Tap
0.2
2
DC
Resistance
±
10%
(ohms)
8.0
0.24
Mm.
Operating
(Amps)
+0
-60%
0.2 2.0
Carry
Continuous
(Amperes)
0.3
3
Carry
30
Amps
for
(sec.)
0.03
4
Carry
10
Amps
for
(sec.)
0.25
30
60
Hz
Impedance
(ohms)
68.6
0.73
If
the
tripping
current
exceeds
30
amperes,
an
auxiliary
relay
should
be used,
the
connections
being
such
that
the tripping
current
does
not
pass through
the
contacts
or
the
target
and
seal-in
coils
of
the
protective
relay.
CONTACTS
The current-closing
rating
of
the
contacts
is
30
amperes
for
voltages
not
exceeding
250
volts.
The
current-carrying
rating
is
limited
by the
ratings
of
the
seal—in
unit.
-8-