GE JBCV51M User manual

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DESCRIPTION
.
APPLICATION
RATINGS
TIME
OVERCURRENT
UNIT
INSTANTANEOUS
OVERCURRENT
UNIT
(DIRECTIONALLY
CONTROLLED)
DIRECTIONAL
UNIT
INSTANTANEOUS
UNT
(NON-DIRECTIONALLY
CONTROLLED)
TARGET
AND
SEAL-IN
UNITS
CONTACTS
OPERATING
CHARACTERISTICS
PICKUP
RESET
(Tune
Overcurrent
Urift)
OPERATING TIME
BURDENS
CONSTRUCTION
DIRECTIONAL UNIT
LOW
GRADIENT
CONTACT
BARREL CONTACT
TIME OVERCURRENT
UNIT
TARGET
AND
SEAL-IN
UNITS
INSTANTANEOUS
OVERCURRENT
UNIT
(DIRECTIONALLY
CONTROLLED)
INSTANTANEOUS
UNIT
(NON-DIRECTIONALLY
CONTROLLED)
RECEIVING,
HANDLING
AND
STORAGE
ACCEPTANCE
TESTS
VISUAL
INSPECTION
MECHANICAL
INSPECTION
TOP
UNIT
(bc)
MIDDLE
UNIT
(TOC)
BOTTOM UNIT
(DIR)
TARGET
AND
SEAL-IN
UNITS/
INSTANTANEOUS
UNIT
DRAWOUT
RELAYS GENERAL
POWER REQUIREMENTS
GENERAL
TARGET
AND SEAL-IN
UNITS
PICKUP
AND
DROPOUT
TEST
TIME
OVERCURRENT
UNIT
CURRENT
SETTING
TIME
SETTING
PICKUP
TEST
TIME
TEST
DIRECTIONAL
UNIT
POLARITY
CHECK
INSTANTANEOUS
UNIT
(DIRECTIONALLY
CONTROLLED)
PICKUP
SETTING
GEK—4985O
CONTENTS
PAGE
3
INSTANTANEOUS
UNIT (NON-DIRECTIONALLY
4
CONTROLLED)
5 INSTALLATION
5
LOCATION
MOUNTING
5
CONNECTIONS
6
INSPECTION
CAUTION
6
OPERATION
6
TARGET
AND
SEAL-IN
UNITS
7
TIME
OVERCURRENT
UNIT
7
DIRECTIONAL
UNIT
7
INSTANTANEOUS
OVERCURRENT
UNIT
7
(DIRECTIONALLY
CONTROLLED)
7
INSTANTANEOUS
UNIT (NON-DIRECTIONALLY
7
CONTROLLED)
9
PERIODIC
CHECKS
AND
ROUTINE
9
MAINTENANCE
9
TARGET
AND
SEAL-IN UNITS
9
TIME
OVERCURRENT UNIT
10
DIRECTIONAL
UNIT
10
INSTANTANEOUS
OVERCURRENT
UNIT
(DIRECTIONALLY
CONTROLLED)
10
INSTANTANEOUS
UNIT (NON-DIRECTIONALLY
CONTROLLED)
11
SERVICING
11
TARGET
AND
SEAL—IN
UNITS
11
TIME
OVERCURRENT
UNIT
11
DISK
AND
BEARINGS
11
CONTACT
ADJUSTMENT
11
CHARACTERISTICS
CHECK
AND
11
ADJUSTMENTS
12
DIRECTIONAL
UNIT
BEARINGS
12
CUP
AND
STATOR
12
CONTACT
ADJUSTMENTS
12
BIAS
TORQUE
ADJUSTMENT
12
CLUTCH
ADJUSTMENT
12
INSTANTANEOUS
OVERCURRENT
UNIT
13
(DIRECTIONALLY
CONTROLLED)
13
BEARINGS
13
CUP
AND
STATOR
14
CONTACT
ADJUSTMENTS
14
CLUTCH
ADJUSTMENT
14
INSTANTANEOUS
UNIT
(NON—DIRECTIONALLY
14
CONTROLLED)
CONTACT
CLEANING
14
RENEWAL
PARTS
14
15
15
15
15
15
15
15
15
15
16
16
16
16
16
16
16
16
16
16
17
17
17
17
17
17
17
17
17
18
18
19
19
19
19
19
19
19
20
20
2

GEK-49850
PHASE
DIRECTIONAL
OVERCURRENT
RELAYS
WITH
VOLTAGE
RESTRAINT
TYPES JBCV51M
JBCV
5314
JBCV53M(-
)Y1A
JBCV77M
DESCRIPTION
The
Type
JBCV
relays
are
phase
directional
overcurrent relays
with
voltage
restraint.
They
are
used
primarily for
the
protection of
feeders
and
transmission
lines.
They
are
available
with
inverse,
very
inverse
or extremely inverse
time
characteristics.
All
the
JBC
relays
contain
a
time
overcurrent
unit
of the
induction
disk type,
an
instantaneous
over-
current
cup
type
unit
and
an instantaneous
directional
cup
type
unit.
The
directional
unit
is quadrature
polarized
and
it directionally
controls
the
operation
of the
time
overcurrent
and
the
instantaneous
over—
current
units. Because
the
directional unit
is
voltage
restrained,
the
JBCV
relays
are
suitable
for
use
in those
applications
where
the
maximum
load
current
can
be
greater
than
the
minimum
available
fault
cur
rent.
Two
target
seal-in
units
are
provided
in
each
of
the
relays.
The
operating
coil
of each
of
these
units
respectively
is
connected
in
series
with the
contacts
of
the
time
overcurrent
unit
and
the
instantaneous
overcurrent
unit.
The
contacts
of each
seal—in
unit
respectively
are
connected
in parallel
with
the
con
tacts
of
the
time
overcurrent
unit
and
the
instantaneous overcurrent
unit
to provide
protection
for
them
and
the
associated control
spring.
Those
relays
having
the
designation
ViA
following the
model
number
also
‘contain
a
Hi—Seismic
instan
taneous
unit
of
hinged
armature
construction.
This
unit
is non—directional
and
has
a self-contained
hand
reset
target that
will
show
whenever the
unit
has
operated.
All
the
JBCV
relays
are
mounted
in
standard ill
size
drawout
cases;
the
outline
and
panel
drilling
dimensions
for
which
are shown
in
Fig.
24.
Internal
connections for
the relays
are
shown
in
Fig.
5,
6
and 7.
Typical external
connections
are
shown
by
Figs.
8
and 9.
Table
I below
lists
the
various models
and
ranges
that
are
available.
TABLE
I
EXTENDED
RANGE
JBCV
RELAYS
Relay
Time
Hi-
Pickup
Range
Int.
Model
Characteristic
Seismic
Hi—Seismic
Time Inst.
Cup
Conn.
JBCV51M(-)A
Inverse
No
-
-
2-16
2—16,
10—80
Fig.
5
JBCV53M(-)A
Very
Inverse
No
-
1.5-12 2-16,
10-80
Fig.
5
JI3CV53M(-)Y1A
Very
Inverse
Yes
6—150 1.5—12
2—16
Fig.
6
JBCV77M(-)A
Extremely
mv.
No
-
1.5-12
2-16,
10—80
Fig.
7
These
instructions
do
not
purport
to
cover
all
details
or
variations
in
equipment
nor
to
provide
for
every
possible
contingency
to
be
met
in
connection
with
installation,
operation
or
maintenance.
Should
further
information
be
desired
or
should
particular
problen’s
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
NEM.4
standards;
but
not
such
assurance
is
given with
respect
to local
codes
and
ordinances
because
they
vary
greatly.
3

GEK-49850
APPLICATION
The
Type
JBCV
relays
are
phase
directional
overcurrent
relays
that
are
used
primarily
as
phase fault
detectors
in
transmission
line
or
feeder
protective
relaying
schemes.
JBCV
relays are
used
for
phase
fault
protection
when
it
is
‘rcessary
to
distinguish
between fault
conditions
and
maximum
load.
The
relay
is
prevented
from
trippg
on
heavy
load
currents
because
the
directional
unit
will
be restrained
due
to
the
system
voltage being
maintained.
When
a
fault
occurs,
the
restraining
torque
in
the
directional
unit
will
collapse as
the
voltage
drops,
thus
permitting
the
relay
to
trip
even
at
fault
currents
below
the
maximum
load
current.
Each
relay
contains a
time
overcurrent
unit
and
an
instantaneous
overcurrent
unit
that
are
both
torque
controlled
by
the
instantaneous
directional unit.
The
directional
unit
is
quadrature
polarized;
i.e.,
the
“a’
phase
relay
uses
‘a”
phase
current and
‘b—c”
voltage,
etc. The
angle
of
maximum
torque of
the
direc
tional unit
is
approximately
45
degrees;
i.e.,
maximum
torque
will
occur
for relay
current
lagging
the
unity
power
factor
position
by 45
degrees, or
conversely,
leading
the
quadrature voltage
by 45
degrees.
The
differences
between
the various
models
covered
by
this
instruction
book
are
shown
in
Table
I.
Inverse
time
relays should
be
used
on
systems
where
the
fault
current
flowing
through
a
given
relay
is
influenced
largely
by
the
system
generating capacity
at
the
time
of
the
fault.
Very
inverse
time
and
ex
tremely
inverse
time
relays
should
be
used
in cases
where
the
fault
current
magnitude
is
dependent mainly
upon
the
location
of
the
fault
in
relation
to
the
relay,
and
only
slightly
or
not
at
all
upon
the
system
generating
setup.
The
reason
for
this
is
that
relays
must
be
set
to
be
selective
with
maximum
fault cur
rent
flowing.
For
fault
currents
below
this
value,
the
operating
time
becomes
greater
as
the
current is
decreased.
If
there is
a
wide
range
in
generating
capacity,
together
with
variation
in
short-circuit
current
with
fault
position,
the
operating
time
with
minimum
fault
current may
be
exceedingly
long
with
very
inverse
time
relays
and
even
longer with
extremely
inverse
time
relays.
For
such
cases,
the
inverse
time
relay is
more
applicable.
The
choice
between
very
inverse
and
extremely
inverse
time
relays
is
more
limited
than
between
them
and
the
inverse time
relay
as
they
are
more
nearly
alike
in
their
time—current
characteristic
curves.
For
grading
with
fuses
the
extremely
inverse time
relay should
be
chosen
as
the
time—current
curves
more
nearly match
the
fuse
curve.
Another advantage
of
the
extremely
inverse
relay
is
that
it
is
better
suited
than both
the
inverse and
very
inverse
relays
for
picking
up
cold
load.
For
any
given cold
load
pickup
capability,
the
resulting
settings
will
provide
faster
protection
at
high
fault
currents
with
the
extremely
inverse
relay
than with the
less
inverse
relays.
The
operating
time of
the
time
overcurrent
unit
for
any
given
value
of
current
and
tap
setting
is
de
termined
by
the
time
dial
setting. This
operating
time
is
inversely
proportional
to
the
current
magnitude
as
illustrated
by
the
time
curves
in
Figs.
11,
12
and 13.
Note
that
the
current
values
on
these
curves
are
given
as
multiples
of the
tap
setting. That
is,
for
a
given
time
dial
setting,
the
time
will
be
the
same
for
80 amperes
on
the
eight
ampere tap
as
for
50
amperes
on
the
five
ampere
tap,
since
in
both
cases,
the
current
is
ten
times
tap
setting.
If
selective
action of
two
or
more
relays is
required,
determine
the
maximum
possible
short-circuit
current
of
the
line
and
then
choose a
time
value
for
each
relay
that
differs
sufficiently
to
insure the
proper
sequence in
the
operation
of
the
several
circuit
breakers.
Allowance
must
be made
for
the
time
involved
in
opening
each
breaker
after
the
relay
contacts
close.
The
instantaneous
cup
unit
is
torque
controlled
by
the
directional
unit.
When
it
is
used
for
direct
tripping,
it
will
only
be
necessary
when
determining
a setting
to
consider
the
maximum
current
that
the
instantaneous
unit
will
see
for
a
fault
at
the
remote
terminal.
The
instantaneous
cup
unit
has
low
tran
sient
overreach.
It
should
be
set
with
a
margin
of
at
least
10
percent above
the
maximum current for
a
remote fault
neglecting transient
overreach.
The
‘(lA
relays
contain
a
Hi-Seismic
instantaneous
overcurrent
unit.
This
unit
may
be
set
high
to
pro
vide
direct
tripping for
heavy
internal
faults.
In
determining the
setting for
this
unit
when
it
is
used
for
direct
tripping,
it
will
be
necessary
to
consider
the
maximum
external
fault
for
faults at
each
end
of
the
line
because
the
unit
is
non-directional.
The
unit
should
be
set
with
a suitable
margin
above
the
maximum
external
fault
taking
into
account
the
effects
of
transient
overreach
as
illustrated
in
Fig.
16.
The
red
jumper
leads
between
studs
18
and
19
and
19
and
20
are
located
inside
the
case
on
the
cradle
block
and
may
be
removed
to
provide
external
torque
control
of
the
time
overcurrent
unit
(TOC)
and
the
instantaneous
overcurrent
unit
(bc)
respectively.
If
external
torque
control of
either
or both
units
is
4

GEK-49850
required,
remove
the
red
Jumper
lead
associated
with the
unit(s)
to
be
controlled,
and
connect
the external
control
contacts
between
the
appropriate studs.
Note
that
the
units
will
still
be
torque
controlled
by
the
directional
unit
in
addition
to
the
external
control.
RAT
INOS
Ratings
of
the
operating
current
circuits
of
the
TOC
(time
overcurrent),
directional
controlled
IOC
(instantaneous overcurrent)
and
the
directional
units
are
shown
individually.
However,
since
all
operating
current
circuits
are
normally connected
in
series,
the
operating
coil
ratings
of
all
three units
should
be
considered
in
determining
the
rating
of the
entire operating
circuit.
TIME OVERCURRENT
UNIT
The
one second
ratings
of
the
TOC units,
relay
terminals
2
and
4,
are
all
260
amperes.
taps
and
the continuous
ratings
are
shown
in
Tables
2,
3
and 4.
Note
that
separate
tables
the JBCV51,
JBCV53 and
JBCV77
models.
TABLE
2
The
available
are
given for
CONTINUOUS
RATING
OF
INVERSE
TIME
OVERCURRENT
UNIT
CONTINUOUS
RATING
OF
EXTREMELY
INVERSE
TIME
OVERCURRENT
UNIT
1.5
—
12.0 AMP
RANGE JBCV77
J
TAP
1.5
2.0
2.5
3.0
4.0 5.0
6.0
7.0
8.0
10.0
12.01
RATING
9.5
10.5
11.5
12.5 14.0
15.5
17.0 18.0
19.0
20.0
2O.j
INSTANTANEOUS
OVERCURRENT
UNIT (DIRECTIONALLY
CONTROLLED)
Ranges and
ratings
of the
IOC
units,
relay
terminals
2
and
3
are
shown
in
Table
have
dual
ratings
obtained
by
series
or
parallel
connections.
5.
The
operating
coils
TABLE
3
CONTINUOUS
RATING
OF
VERY
INVERSE TIME
OVERCURRENT
UNIT
TABLE
4
5

GEK-
49850
DIRECTIONAL UNIT
The
directional
unit
operating
coil,
relay
terminals
5
and
6,
has
a five
a 200
ampere
one
second
rating. The
potential
polarizing
circuit,
terminals
circuit,
terminals
9
and
10,
are continuously
rated.
INSTANTANEOUS
UNIT (NON-DIRECTIONALLY
CONTROLLED)
The
instantaneous
unit
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
leads
T
and
E
at
terminal
15.
See
Table
6
and
the
applicable
interntal
connections
referenced
in Table
1.
For
the
H range,
connect
lead
T
to
terminal
15
and
lead
E
to
the
auxiliary
terminal
that
is
mounted
on
terminal
15.
For
range
L,
reverse
leads
T
and
E.
TABLE
6
CONTINUOUS
AND
ONE
SECOND RATINGS
OF
NON-DIRECTIONALLY
CONTROLLED
IOC
UNIT
One
**
Continuous
Second
Instantaneous
Range
Range
Rating Rating
Unit
(Amps)
(Amps)
(Amps) (Amps)
6
-
150
L
6
— 30
10.2
260
H
30
-
150
19.6
**The
range
is
approximate,
which
means
that
6-30,
30—150 may
be
6-28,
28-150. There will
always
be
at
least
one
ampere
overlap
between
the
maximum
L
setting and
the
minimum
H
setting.
When
ever
possible,
always
select
the
higher
range,
since
it
has
the
higher
continuous
rating.
TARGET
AND
SEAL-IN
UNIT
The
rating
and
impedance
of
the
seal-in
unit
for
the 0.2 and
2 ampere
taps
are
given
in
Table
7.
The
tap
setting used
will
depend
on
the
current
drawn
by
the
trip
coil.
The
0.2
ampere
tap
is
for
use
with
trip
coils
which
operate
on
currents
ranging
from
0.2
up
to
2.0
amperes,
at
the
minimum control
voltage.
If
this
tap
is
used
with
trip
coils requiring
more than
two
am
peres, there is
a
possibility
that
the
resistance
of
seven
ohms
will
reduce
the
current
to
so
low
a
value
that the
breaker
will
not
be
tripped.
The
two
ampere
tap
should
be
used
with
trip
coils
that
take
two
amperes
or
more
at
minimum
control
voltage,
provided
the
current
does
not
exceed
30
amperes
at
the
maximum
control
voltage.
If
the
tripping
current
exceeds
30
amperes,
the
connections
should
be
arranged
so
that
the
induction
unit
contacts
will
operate
an
auxiliary
relay
which
in
turn
energizes
the
trip
coil
or
coils.
On
such
an
application,
it
may
be
necessary
to
connect
a
loading
resistor
in
parallel
with
the
auxiliary
relay
coil
to allow
enough
current
to
operate
the
target
seal—in
unit.
TABLE
5
CONTINUOUS
AND
ONE
SECOND
RATINGS
OF
DIRECTIONALLY
CONTROLLED
IOC
UNIT
Total
Pickup
Continuous
One
Second
Range
Connections
Range
Rating Rating
(Amps)
Amps
(Amps)
(Amps)
2-16
Series
2-8
5.0
200
Parallel
4—16
6.5
260
10-80
Series
10-40
9.0
220
Parallel
20-80
15.0
260
ampere
continuous
rating and
7
and
8,
and
the
restraint
6

GEK-
49850
TABLE
7
SEAL-IN
UNIT
RATINGS
0.2
TAP
2.0
DC
RESISTANCE
÷
10%
(OHMS)
7
0.13
MIN.
OPERATING
(AMPERES)
+
0-25%
0.2 2.0
CARRY
CONT.
(AMPERES)
-
0.3 3.0
CARRY
30
AMPS
FOR
(SEC.)
-
0.03
4.0
CARRY
10
AMPS
FOR
(SEC.)
—
0.25
30.0
60
HZ
IMPEDANCE
(OHMS)
—
52.0 0.53
CON
TACT
S
The
current—closing
rating
of the
induction
unit
contacts is
30
amperes
for
voltages
not exceeding
250
volts.
Their current-carrying rating
is
limited
by
the
tap
rating
of
the
seal—in
unit.
OPERATING
CHARACTERISTICS
PICKUP
At
rated
voltage
and
maximum
torque
angle,
the
directional
unit
will
pick
up
at
9
+ 10
percent
amperes.
At
restraint
voltages
less
than
rated,
the
operating
current
is also less.
This
relationship
is
shown
by
the
curve
in
Fig.
10.
Pickup
of the
TOC
units
is
defined
as
the
current required
to
close
the
contacts from
the
0.5
time
dial
position.
The
pickup
value
is
within
five
percent
of
tap
value.
The
pickup
of the
directionally
controlled
IOC
unit
can
be adjusted
over
an
eight—to—one
range
as
indicated
in Table
5.
RESET
(TIME
OVERCURRENT
UNIT)
Inverse
time
overcurrent
units
reset
at
90
percent
of
the
minimum
pickup
current,
very
inverse
time
units
at
80
percent
and
extremely inverse
time
units
at
85
percent.
When
the
relay
is
de-energized,
the
time
required
for
the
disk
to
completely
reset
to
the
number
10
time
dial
position is
approximately
six
seconds
for
inverse
time
relays
and
60
seconds
for
very
inverse-
time
and
extremely
inverse-time
relays.
OPERATING TIME
The
time
curves
of
the
TOC
units
are
shown
in
Figs.
11,
12
and
13
respectively
for
inverse-time,
very
inverse-time
and
extremely
inverse-time
relays.
For
the
same
operating
conditions,
the
relay will
operate
repeatedly
within
one
or
two
percent
of
the
same
time.
The
time
curves
for
the
directionally
controlled
IOC
units
are
shown
in
Fig.
14.
The
time—current
characteristic
of
the
Hi—Seismic
non—directionally
controlled
TOC
unit
is
shown
by
Fig.
15
and
its
transient
overreach
characteristic
is
shown
by
Fig.
16.
BURDENS
Tables
8
and
9
give
the
directional
unit
burdens of the
potential
and
current
circuits
respectively.
Table
10
gives the
total
burden
of the
time
overcurrent
unit
plus
the
instantaneous
overcurrent
unit.
7

GEK-49850
TABLE
8
DIRECTIONAL UNIT
POTENTIAL
CIRCUIT
BURDENS
AT
60
CYCLES
AND
RATED
VOLTS
VOLT
POWER
WATTS
CIRCUIT
AMPERES
FACTOR
Polarizing
15.2
0.93
14.1
Restraint
5.9
0.66
3.9
IMPED.
VOLT-
POWER
(OHMS)
AMPERES
FACTOR
0.12
I
3.00
I
0.52
RANGE
BURDENS
AT
MIN.
PICKUP
BURDEN
OHMS
(Z)
TIME
———
MIN.
TAP
OF
TOC
UNIT
CHARACTER-
TOC
IOC
IOC
UNIT
3
TIMES
10
TIMES
AT 5
ISTIC
UNIT
UNIT
CONNECTIONS
R
**
+VA
P.F.
MIN.
P.U.
MIN.
P.U.
AMPS
2-16
Series
2-8
0.61
2.01
2.10
8.4
0.29 1.21 0.85
53
Parallel
4-16
0.42
1.54
1.60
6.4
0.26 0.76 0.43
40
Inverse
2-16
10-80
Series 10-40
0.45
1.58
1.65
6.6
0.27 0.81
0.48
41
Parallel
20-80 0.38
1.45
1.50
6.0
0.25
0.67
0.34
38
2—16
Series
2—8
0.47
1.10
1.20
2.7
0.39
1.20 0.53
30
Very
Parallel
4-16
0.28
0.63
0.69 1.6
0.41
0.69
0.47
17
Inverse
1.5-12
10-80
Series
10-40
0.31
0.67
0.74
1.7
0.42
0.74
0.52 19
Parallel
20-80
0.24 0.54 0.59
1.3
0.41
0.59
0.38
15
2-16
Series
2-8
0.33 0.72
0.79
1.8
0.42 0.79
0.70
20
Extremely
Parallel
4-16
0.13 0.25
0.28
0.5
0.46
0.28
0.28
7
Inverse
1.5-12
10-80
Series
10-40
0.16
0.29
0.33
0.7
0.49 0.33 0.33
8
Parallel
20-80
0.10 0.16
0.19
0.4
0.53
0.19
0.19
5
**The
impedance values
given
are
those
for
the
nhiriinium
tap
of
each
relay.
The
impedance
for
other taps,
at
pickup
current
(tap
rating),
varies inversely
approximately
as
the
square
of
the
current
rating.
Example:
for
the
very
inverse
relays, 1.5/12
amperes, with
impedance
of
the
1.5
ampere
tap
of
1.20
ohms,
the
impedance
of
the
three
ampere
tap,
at
three
amperes,
is
approximately
(1.5/3)2
X 12O
= 0.3
ohms.
+Sorne
companies
list
relay
burdens only
as
the volt-ampere
input
to
operate
at
minimum
pickup. This
column
is
included
so
a
direct
comparison
can
be
made.
It
should
not
be
used in
calculating
volt—ampere
burdens
in a
CT
secondary
circuit, since
the
burden at five
amperes
is
used
for
this
purpose.
*Calculated
from
burden
at
minimum pickup.
TABLE
9
DIRECTIONAL
UNIT
CURRENT
CIRCUIT
BURDENS AT
60
CYCLES
AND 5
AMPS
TABLE
10
BURDENS
OF
OVERCURRENT
UNITS
(TIME
AND
INSTANTANEOUS)
AT
60
CYCLES
8

GE K-4
9850
TABLE
11
BURDEN OF
NON-DIRECTIONALLY
CONTROLLED
INSTANTANEOUS
UNIT
Inst
Unit
Ran
e
Mm.
Burdens
at
Mm.
Burdens
Ohms
(Z)
HZ
Range
Pickup
Pickup (Ohms)
Tinies
Pickup
p
,
p
(Amps)
R
Z
3
10 20
L
6-30 6
0.110 0.078 0.135 0.095
0.081 0.079
6-150
60
H
30-150 30
0.022
0.005
0.023 0.022
0.022 0.022
CONSTRUCTION
Type
JBCV
relays
are
single
phase, directional
overcurrent
relays
with
voltage
restraint.
They
are
available
with
inverse,
very
inverse
or
extremely
inverse
time-current
characteristics.
The
JBCV
relays
consist
of
three
main
units, an
instantaneous
overcurrent
unit
(top)
of the induction-cup
type,
a
time
overcurrent
unit
(middle)
of
the
induction—disk
type,
and
an
instantaneous
power—directional
unit
(bottom)
of
the
induction-cup
type.
The
directional
unit
is potential
polarized
and,
by
means of
its
closing
con
tacts,
directionally
controls
the
operation
of
both
the
time
overcurrent
and
instantaneous
overcurrent
units.
All
units
are
mounted
in
the
L2,
(large
double—ended)
drawout
case.
The
IOC
(instantaneous
over—
current) unit
and
the
TOC
(time
overcurrent)
unit
each
have
an
associated
target
and
seal-in unit.
The
JBCV53M(-)Y1A,
as
shown
by
Table
1,
has
an
additional
IOC
unit
which
is
of
the
hinged
armature
type.
DIRECTIONAL UNIT
The
directional
unit
is
of
the
induction-cylinder
construction
with a
laminated
stator
having
eight
poles
projecting
inward
and
arranged symmetrically
around
a
stationary
control
core.
The
cup-like
aluminum
induction
rotor
is
free
to
operate
in
the
annular air
gap
between
the
poles
and
the
core.
The
poles
are
fitted
with
voltage
restraint,
current operating,
and
potential
polarizing
coils.
The
principle
by
which
torque
is
developed
is
the
same as
that
of
an
induction
disk
relay
with
a
wattinetric
element,
although,
in
arrangement
of
parts,
the
unit
is
more
like
a
split—phase
induction
motor.
The
induction—cylinder
construction
provides higher
torque
and
lower
rotor
inertia than
the
induction—disk
construction,
resulting
in a
faster
and
more
sensitive
relay.
Low
Gradient
Contact
The
directional
unit
contacts
(left
front),
which
control
the
time
overcurrent
unit
are
shown
in
Fig.
17. They
are
of
the
low
gradient
type
specially
constructed
to
minimize
the
effects
of
vibration.
Both
the
stationary
and
moving
contact
brushes
are
made
of
low
gradient
material
which,
when
subjected
to
vibration,
tend to
follow one
another,
hence,
they
resist
contact
separation.
The
contact
dial
(A)
supports the
stationary
contact
brush
(B)
on
which
is mounted
a conical
contact tip
(C).
The
moving
contact
arm
(D)
supports
the
moving contact
brush
(E)
on
which is
mounted a
button
contact
tip
(F).
The
end
of
the
moving
contact
brush bears
against
the
inner
face
of
the
moving
contact
brush
retainer
(B).
Similarly,
the
end
of
the
stationary
contact brush
bears
against
the
inner
face
of
the
stationary
contact
brush retainer
(H). The
stationary
contact
support (K)
and
the
contact dial
are
assembled
together
by
means
of
a
mounting
screw
(L)
and
two
locknuts
(N).
Barrel Contact
The
directional
unit
contacts
(right
rear),
which
control
the
instantaneous
overcurrent
unit,
are
shown
in
Fig.
18.
They
are
specially
constructed
to
suppress
bouncing.
The
stationary
con
tact
(B)
is
mounted
on
a flat
spiral
spring
(F) backed
up by
a
thin
diaphragm
(C).
These
are
both
mounted in
a
slightly
inclined
tube
(A). A
stainless
steel
ball
(B)
is
placed
in
the
tube
before
the
diaphragm
is
assembled.
When
the
moving
contact hits
the
stationary
contact, the
energy
of
the
former
is
imparted
to
the
latter
and
thence
to
the
ball,
which
is
free
to
roll
up
the
inclined
tube.
Thus,
the
moving
contact
comes to
rest
with
substantially
no
rebound or
vibration.
To
change
the
stationary
contact
mounting
spring, remove
the
contact barrel
and
sleeve
as
a
complete
unit
after
loosening
the
screw
at
the
front
of
the
contact
block. Unscrew the
cap
(E).
The
contact
and
its
flat
spiral
mounting
spring
may
then
be
removed.
9

GE
K-49850
TIME
OVERCURRENT
UNIT
The
inverse
time
and
very
inverse
time
overcurrent
units consist
of
a
tapped
current
operating
coil
wound on
a
U—magnet
iron
structure.
The
tapped
operating
coil
is
connected to
taps
on
the
tap
block.
The
U-magnet
contains
wound
shading
coils
which
are
connected
in
series
with
a directional
unit contact.
When
power
flow
is
in
such
a
direction
as
to
close
the
directional
unit contacts,
the
shading
coils
act
to
produce
a
split-phase
field
which, in
turn,
develops
torque
on
the
operating
disk.
The
extremely
inverse
time
overcurrent
unit
is
of the
wattmetric
type
similar
to
that
used
in
watthour
meters except
as
follows:
the
upper
portion
of
the iron
structure
has
two
concentric
windings
on
the
mid
dle
leg
of
the
magnetic
circuit.
One
of
these is
a tapped
current
winding
connected
to
taps
on
the
tap
block;
the
other
is
a
floating
winding
which
is
connected
in
series
with
the
directional
unit
contacts,
a
resistor,
a
capacitor
and
the
two
coils
on
the
lower
legs
of
the
magnetic
circuit.
When
power
is
in
such
a
direction
as
to
close
a directional
unit
contact,
the
unit
develops
torque
on
the
operating
disk.
The
disk shaft
carries
the
moving
contact
which
completes
the
trip
circuit
when
it
touches the
sta
tionary contact
or
contacts.
The
shaft
is
restrained
by
a
spiral spring
to
give
the proper
contact-closing
current, and
its
motion
is
retarded
by
a
permanent
magnet
acting
on
the
disk
to
produce
the
desired
time
characteristic.
The
variable
retarding
force
resulting
from
the
gradient
of the
spiral spring is
compen
sated
by
the
spiral
shape
of
the
induction
disk,
which
results
in
an
increased
driving
force
as
the
spring
winds
up.
The
torque
control
circuits
of
both
the
time
overcurrent
and
instantaneous
overcurrent units
are
wired
to
terminals
on
the
relay
contact
block.
These
terminals
are shorted
together
by
internally
connected
red
jumper
leads
when
the
relays
leave
the
factory
(see
Figs.
5 to
7
inclusive).
If
external
torque
con
trol
is
desired, these
jumper
leads
should
be
removed.
TARGET
AND
SEAL-IN
UNITS
The
seal-in
units
for
both
the
TOG
and
lOG
contacts
of
the
JBCV51M, JBCV53M
and
JBCV77M
relays
are
mounted
on
the
lOG
middle
unit.
On
the
JBCV53M(-)Y1A
relay
the
right
hand
seal—in
unit
is
replaced
by
the
non—directionally
controlled
lOG
unit
and
the
seal—in
unit
is
moved
to
the
left
side
of
the
directional
(lower) unit.
The
left
seal-in
unit
operates
in
conjunction
with
the
time
overcurrent
unit
contacts
and
is
labeled
TIME”. Its
coil
is
in
series and
its
contacts
in
parallel
with
the
main
contacts of
the
time
overcurrent
unit
so
that
when
the
main
contacts close,
the
seal—in
unit
will
pick
up
and
seal
in
around
the
main
con
tact.
The
right seal-in
unit,
labeled
“INST.
operates
in
conjunction
with
the
instantaneous
overcurrent
unit.
Its
coil
is
in
series
with
the
instantaneous
unit
contact and
a
contact of
the
directional
unit,
and
its
contact
is
connected
to
seal
in
around
these
two
contacts
when
the
unit
operates.
Both
seal—in units
are
equipped
with
targets
which are
raised
into
view
when
the
unit operates.
These
targets
latch
and
remain exposed
until
manually
released
by
means
of
the button
projecting
below the
lower—
left
corner
of
the
cover.
INSTANTANEOUS
OVERCURRENT
UNIT
(DIRECTIONALLY
CONTROLLED)
The
instantaneous
overcurrent
unit
is
similar
in
construction
to
the
directional
unit
described
above,
differing
only
in
coil turns
and
connections.
The
four corner
coils
consist of
two
windings,
an
inner
winding
consisting
of
a
large number
of
turns
of
fine
wire, and
an
outer
winding
having
a
few
turns
of
heavy
wire.
The
outer
windings
of
the
corner
coils
are
connected
either
in
series or
in
parallel with
the
side
coils
by
tap
links
provided
on
the
relay; these
series or
parallel
combinations
are
connected
in
series
with
the
operating
coil
of
the
TOG
unit.
The
inner
windings
of
the corner
coils
are
all
connected
in
series,
and
in
turn
are
connected
in
series
with
a
capacitor
and
a
contact
of
the
directional
unit.
This
circuit
thus
controls
the
torque
of the
instantaneous
overcurrent
unit.
When
the
directional
unit
contacts are
open,
the
instantaneous
overcurrent
unit
will
develop
no
torque.
When
the
directional
unit
contacts
are
closed,
the
instantaneous
overcurrent
unit
will
develop
torque in
proportion
to
the
square
of
the
current.
The
instantaneous
overcurrent
unit
develops
operating
torque
in
a
direction
opposite
to
that of
the
directional
unit. This
makes
the
relay
less
susceptible
to
the
effects
of
shock.
10