GE SLYG81A User manual

INSTRUCTIONS
GEK
-
49813
C
STATIC
,
THREE
-
PHASE
DIRECTIONAL
GROUND
-
DISTANCE
RELAY
TYPE
SLYG
81
A
GENERAL ELECTRIC
Courtesy of NationalSwitchgear.com

GEK
-
49813
CONTENTS
PAGE
DESCRIPTION
APPLICATION
RATINGS
GENERAL
SURGE WITHSTAND
CAPABILITY
POWER
SUPPLY
CONTACTS
TARGET
CHARACTERISTICS
OPERATING
PRINCIPLES
OPERATING
TIME
SENSITIVITY
BURDENS
CIRCUIT
DESCRIPTION
CALCULATION OF
SETTINGS
FIRST
ZONE
RELAY
SETTING
SECOND ZONE
RELAY
SETTING
CONSTRUCTION
RECEIVING
,
HOLDING
AND
STORAGE
ACCEPTANCE TESTS
VISUAL
INSPECTION
MECHANICAL
INSPECTION
CASE
AND
CRADLE
BLOCKS
TARGET
UNIT
TELEPHONE
RELAY
ELECTRICAL TESTS
,
GENERAL
DIELECTRIC
TESTS
DETAILED
TESTING
INSTRUCTIONS
INSTALLATION PROCEDURE
INTRODUCTION
SURGE
GROUND
AND RELAY
CASE
GROUND CONNECTIONS
TEST
PLUGS
INSTALLATION
TESTS
PERIODIC
TESTING
AND
ROUTINE
MAINTENANCE
CONTACTS
ELECTRICAL
TESTS
SERVICING
RENEWAL
PARTS
CAUTION
ADDITIONAL
CAUTION
APPENDIX
I
LIST
OF
FIGURES
3
4
5
5
6
6
6
7
7
7
8
9
9
10
13
13
14
14
16
16
16
16
16
17
17
17
17
18
22
22
22
23
23
24
24
24
24
27
27
27
28
29
Cover
Photo
(
8043551
)
2
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GEK
-
49813
STATIC
,
THREE
-
PHASE
DIRECTIONAL
GROUND
-
DISTANCE
RELAY
TYPE
SLYG
81
A
DESCRIPTION
The
Type
SLYG
81
A
relay
is
a
three
-
phase
,
first
-
or
second
zone
static
ground
-
distance
,
relay
.
It
is
available
with
ratings
of
60
hertz
,
5
amperes
;
50
hertz
,
5
amperes
;
or
50
hertz
,
1
ampere
.
Five
-
ampere
-
rated
relays
are
available
with
continuously
adjustable
ohmic
-
reach
ranges
of
0.1
to
4
ohms
or
0.75
to
30
ohms
.
One
-
ampere
rated
relays
are
available
with
continuously
adjustable
ohmic
-
reach
ranges
of
0.5
to
20
ohms
or
3.75
to
150
ohms
.
DC
power
-
supply
voltages
available
are
48
,
110
,
or
125
.
A
250
volt
rating
is
available
with
an
external
pre
-
regulator
.
Contact
outputs
are
provided
for
tripping
(
two
contacts
,
each
with
target
)
and
there
is
contact
connected
to
positive
for
auxiliary
functions
.
The
relay
is
mounted
in
a
deep
,
large
-
size
,
double
-
ended
drawout
(
L
2
D
)
case
.
The
Type
SLYG
81
A
relay
may
be
used
in
a
"
stepped
distance
"
protection
as
the
first
,
second
or
third
zone
of
ground
protection
.
It
may
also
be
used
as
an
underreaching
or
overreaching
tripping
relay
in
any
of
the
directional
-
comparison
scheme
.
If
the
directional
-
comparison
scheme
uses
ground
-
distance
blocking
relays
,
the
Type
SLYG
82
A
blocking
relay
(
described
in
instruction
book
GEK
-
49814
)
should
be
used
in
the
scheme
to
coordinate
with
the
SLYG
81
A
tripping
relay
.
The
SLYG
81
A
has
a
"
variable
mho
"
characteristic
,
which
provides
an
optimum
accommodation
of
fault
resistance
.
The
functional
block
diagram
is
shown
in
Figure
1
.
The
internal
connections
are
shown
in
Figure
2
and
the
external
connections
are
shown
in
Figure
3
.
These
instructions
do
not
purport
to
cover
all
details
or
variations
in
equipment
nor
provide
for
every
possible
contingency
to
he
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
NEMA
standards
;
but
no
such
assurance
is
given
with
respect
to
local
codes
and
ordinances
because
they
vary
greatly
.
3
Courtesy of NationalSwitchgear.com

GEK
-
49813
APPLICATION
The
SLYG
81
A
utilizes
a
four
-
input
phase
-
angle
comparator
for
ground
-
distance
measurement
for
each
phase
.
The
four
inputs
for
the
phase
-
A
-
to
-
ground
measurement
are
:
(
a
)
OA
-
lo
)
ZRI
+
KOIOZRO
-
TVAG
Operating
Quantity
#
1
Polarizing
Quantity
(
b
)
VRG
Z
90
°
V
3
(
c
)
C
KQIOZRO
~
VQ
.
#
2
Polarizing
Quantity
Overcurrent
Supervision
(
d
)
IQZRO
where
:
is
the
faulted
phase
current
is
the
zero
-
sequence
component
is
the
phase
(
positive
-
and
negative
-
sequence
)
base reach
tap
with
an
impedance
angle
85
°
is
the
neutral
(
zero
-
sequence
)
base reach
with
an
impedance
angle
of
75
°
is
the
"
adjustable
"
phase
-
to
-
ground
restraint
voltage
is
the
"
quadrature
"
voltage
shifted
90
leading
"
A
•
o
ZRI
ZRO
TVAG
VRrZ
90
°
V
3
is
a
ratio
tap
compensate
for
the
magnitude
ratio
between
the
zero
-
and
positive
-
sequence
lines
impedance
is
a
design
constant
(
0.5
per
unit
)
is
the
zero
-
sequence
voltage
atthe
relay
The
use
of
a
four
-
input
comparator
produces
many
advantages
over
previous
designs
in
simplifying
the
application
of
a
ground
-
distance
relay
for
either
first
-
or
second
-
zone
applications
.
The
first
and
second
inputs
(
a
and b
)
to
the
comparator
produce
the
well known
quadrature
-
polarized
ground
-
distance
unit
with
a
"
variable mho
"
characteristic
.
The
"
variable
mho
"
characteristic
increases
in
size
as
the
source
impedance
increases
,
to
accommodate
increasing
fault
resistance
.
The
use
of
the
second
polarizing
quantity
(
c
)
re
*
ricts
the
distance
measurement
to
the
faulted
phase
,
thereby
eliminating
the
need
for
checking
the
unfaulted
phase
unit
for
incorrect
directional
sensing
on
unusual
-
sequence
current
-
distribution
factors
,
or
overreaching
on
heavy
-
load
transfer
.
The
second
polarizing
quantity
(
c
)
also
precludes
the
possibility
of
the
distance
unit
overreaching
on a
double
-
line
-
to
-
ground
fault
with
high
zero
-
sequence
fault
resistance
.
The
high
zero
-
sequence
fault
resistance
can
cause a
fault
beyond
the
reach
of
a
relay
to
appear
within
the
operating
characteristic
of
a
relay
when
only
the
(
a
)
and
(
b
)
inputs
above
are
used
.
K
0
c
Vo
4
Courtesy of NationalSwitchgear.com

GEK
-
49813
The
fourth
input
(
d
)
provides
overcurrent
supervision
to
prevent
operation
on
potential
failure
or
on
the
line
de
-
energizing
transients
that
are
associated
with
lines
with
shunt
reactors
.
The
line
de
-
energizinq
transients
present
a
problem
if
a
relay
operates
on
the
transient
voltages
just
prior
to
a
high
-
speed
reclosure
.
In
addition
,
the
third
and
fourth
inputs
(
c
and
d
)
act
as
a
zero
-
sequence
directional
unit
that
provides
excellent
directional
integrity
.
The
SLYG
81
A
has
an
adjustable
characteristic
that
is
adjusted
by
means
of
the
timer
setting
on
the
characteristic
timer
.
For
short
lines
a
circular
characteristic
is
recommended
,
but
,
for
longer
lines
,
lines
with
unusually
heavy
-
load
transfer
,
or
three
-
terminal
lines
where
very
large
reach
settings
are
applied
,
a
lens
-
shaped
characteristic
is
recommended
.
RATINGS
GENERAL
The
Type
SLYG
81
A
relay
is
designed
for
continuous
operation
in
ambient
temperatures
between
-
20
°
C
and
+
55
°
C
per
ANSI
standard
C
37.90
-
1978
.
In
addition
,
these
relays
will
not
malfunction
nor
be
damaged
if
operated
in
an
ambient
up
to
65
°
C
.
The
current
circuits
of
the
relays
that
are
rated
5
amperes
rms
will
carry
10
amperes
rms
continuously
and
will
carry
250
amperes
rms
for
1
second
.
The
current
circuits
of
the
relays
that
are
rated
1
ampere
rms
will
carry
2
amperes
rms
continuously
and
will
carry
50
amperes
rms
for
1
second
.
The
potential
circuits
are
rated
69
volts
rms
line
-
to
-
neutral
and
can
withstand
110
%
of
this
value
continuously
.
These
relays
are
available
with
either
short
or
long
impedance
ranges
as
shown
in
Table
I
.
TABLE
I
AVAILABLE
REACHES
CURRENT
TRANSFORMER
RATING
ZRI
BASE
REACH
TAP
IN
POSITIVE
-
SEQUENCE
OHMS
ZR
IMPEDANCE
RANGE
IN
POSITIVE
-
SEQUENCE
OHMS
TYPE
0.1
0.1
to
1.0
0.2
to
2.0
0.4
to
4.0
5
AMP
SHORT
0.2
0.4
0.75
0.75
to
7.5
1.5
to
15
3
to
30
5
AMP
LONG
1.5
3.0
0.5
0.5
to
5.0
1.0
to
10.0
2.0
to
20.0
SHORT
1
AMP
1.0
2.0
3.75
3.75
to
37.5
7.5
to
75.0
15.0
to
150.0
1
AMP
LONG
7.5
15.0
5
Courtesy of NationalSwitchgear.com

GEK
-
49813
Selection
of
the desired base
-
reach
tap
(
ZRI
)
is
made
by
means
of
the
four
tap
screws
at
the
lower
rear
of
the
relay
(
see
Figure
4
)
.
All
four
tap
screws
(
0
A
,
0
B
,
0
C
,
and
neutral
)
must
be
in
equal
ohmic
-
tap
positions
.
The
relay
reach
(
ZR
)
of
the
relay
is
continuously
adjustable
,
within
the
range
shown
in
Table
I
for
a
particular
tap
,
by
means
of
a
three
-
gang
precision
potentiometer
at
the
lower
front of
the
relay
(
see
Figure
5
)
.
The
10
-
turn
dial
of
this
potentiometer
is
calibrated
in
percent
restraint
setting
(
T
)
and
is
adjustable
from
10
%
(
fully
counterclockwise
)
to
110
%
(
fully
clockwise
)
.
The
maximum
recommended
setting
is
100
%
.
An
enlarged
picture
of
the
dial
is
shown
in
Figure
15
.
The
relay
reach
is
given
by
equation
(
1
)
:
Relay
Reach
=
ZR
=
100
x
ZRI
(
D
T
where
T
=
Restraint
setting
in
percent
ZR
=
Relay
reach
in
ohms
ZRI
=
Base
reach
tap
in
position
-
sequence
ohms
The
relay
should be
within
5
%
of
the
value
given
by
equation
(
1
)
if
the ambient
temperature
is
within
the
rated
range
of
-
20
°
C
to
+
55
°
C
.
SURGE
-
WITHSTAND
CAPABILITY
These
relays
will
withstand
ANSI C
37.90
A
-
1974
surge
test
without
incorrect
operation
or
damage
to
any
component
.
POWER
SUPPLY
Models
are
available
with
ratings
of
48
'
cits
DC
(
38
to
56
volts
)
,
110
volts
DC
(
88
to
120
volts
)
,
or
125
volts
DC
(
100
to
140
volts
)
.
The
power
supply
contains
a
DC
-
to
-
DC
converter
to
provide
isolation
between
the
DC
input
control
power
and the solid
-
state
circuitry
of
the
relay
.
On
relays
with
DC
control
voltage
in
excess
of
125
volts
,
an
external
pre
-
regulator
is
used
.
This
reduces the
control
voltage
to
125
volts
,
suitable
for
input
to
the
relay
terminals
.
CONTACTS
All
three
of
the
output
contacts
of
the
Type
SLYG
81
A
will
make and
carry
30
amperes
for
tripping
duty
,
but
their
continuous
-
current
ratings
are
limited
by
the
target
ratings
as
listed
in
Table
III
.
The
interrupting
ratings
are
given
in
Table
II
.
6
Courtesy of NationalSwitchgear.com

GEK
-
49813
TABLE
II
INTERRUPTING
RATINGS
OF
OUTPUT
CONTACTS
AMPS
AC
VOLTS
INDUCTIVEtt
NON
-
INDUCTIVE
115
0.75
2.0
230
0.5
1.0
DC
VOLTS
48
1.0
3.0
125
0.5
1.5
250
0.25
0.75
t
+
The
inductive
rating
is
based
on
an
L
/
R
ratio
of
0.04
second
TARGET
Targets
having
0.6
and
2
ampere
taps
are
provided
for
the
output
contacts
between
studs
11
and
12
and
between
studs
13
and
14
.
The
ratings
of
each
of
these
targets
are
qiven
in
Table
III
.
TABLE
III
TARGET
RATINGS
0.6
Amp
Tap
2.0
Amp
Tap
Minimum
Operating
Carry
Continuously
Carry
30
Amps
for
Carry
10
Amps
for
DC
Resistance
60
Hertz
Impedance
0.6
amps
1.2
amps
0.5
sec
.
5
secs
.
0.78
ohm
6.2
ohms
2.0
amps
2.6
amps
3.5
secs
.
30
secs
.
0.18
ohm
0.65
ohm
CHARACTERISTICS
OPERATING
PRINCIPLES
The
mho
characteristic
in
the
SLYG
81
is
obtained
by
converting
relay
currents
into
voltage
signals
(
IZ
)
,
combining
these
IZ
signals
with
signals
proportional
to
the
line
voltage
(
V
)
,
and
measuring
the
angle
between
the
appropriate
combinations
to
obtain
the
desired
characteristic
.
Currents
are
converted
into
IZ
signals
by
means
of
transactors
(
XA
,
XB
,
XC
,
and
Xo
)
that
are
air
gap
reactors
with
secondary
windings
.
The
transactors
are
tapped
on
the
primary
to
provide
the
basic
ohmic
tap
selection
of
0.1
,
0.2
or
0.4
ohms
for
the
5
ampere
short
-
reach
relay
or
0.75
,
1.5
or
3
ohms
for
the
5
ampere
long
-
reach
relay
.
The
1
-
ampere
-
rated
relay
taps
are
0.5
,
1.0
,
or
2.0
ohms
for
the
short
-
reach
relay
and
3.75
,
7.5
and
15
ohms
for
the
long
-
reach
relay
.
7
Courtesy of NationalSwitchgear.com

GEK
-
49813
The
Z
of
the
IZ
quantity
is
the
transfer
impedance
of
the
transactor
and
is
equal
to
VOUT
/
'
IN
-
The
transactor
secondaries
have
loading
resistors
across
them
.
These
resistors
provide
the
desired
angle
between
VOUT
and
IIN
-
This
angle
determines
the
base
reach
of
the
relay
.
Two
additional
quantities
(
"
IOZRO
"
and
"
CKOIOZRO
-
VO
"
)
are
also
compared
to
provide
security
for
faults
other
than
single
-
line
-
to
-
ground
.
The
phase
angle
between
the
four
signals
is
compared
in
a
"
Coincidence
Logic
"
(
CL
)
circuit
that
puts
out
a
rectangular
voltage
pulse
when
these
signals
are
coincident
.
The
width
of
this
block
of
voltage
is
measured
by
an
"
Integrating
Timer
"
(
IT
)
circuit
which
provides
a
trip
-
signal
output
when
the
pulse
width
exceeds
a
preset
duration
.
If
the
timer
is
set
for
90
°
(
that
is
,
4.16
milliseconds
in
a
60
hertz
system
or
5
milliseconds
in
a
50
hertz
system
)
,
a
circular
R
-
X
characteristic
is
obtained
.
If
the
timer
is
set
for
less
than
90
°
,
an
expanded
(
tomato
shaped
)
characteristic
is
obtained
.
If
the
timer
is
set
for
more
than
90
°
,
a
contracted
circle
(
lens
shaped
)
is
obtained
.
Relays
are
shipped
from
the
factory
with
the
timer
set
for
90
°
.
The
timing
diagram
for
a
typical
condition
is
shown
in
Figure
8
.
If
the
100
%
restraint
setting
is
used
and
Kp
is
set
equal
to
the
ratio
of
Zo
'
/
Zi
’
,
phase
-
to
-
neutral
reach
of
the
relay
at
the
angle
0
is
equal
to
the
IZ
base
-
reach
tap
chosen
.
If
a
voltage
tap
other
than
100
%
is
chosen
,
reach
is
increased
in
inverse
proportion
to
the
voltage
tap
.
For
example
,
if
the
50
%
voltage
tap
is
used
,
relay
operation
still
occurs
for
the
same
voltage
applied
to
the
measuring
circuit
,
but
since
the
actual
line
voltage
is
twice
this
amount
,
the
relay
reach
is
twice
as
great
.
Relay
reach
at
the
angle
of
maximum
reach
can
be
calculated
from
the
expression
:
ZR
=
Zfilx
100
T
where
:
T
=
restraint
setting
in
percent
ZRI
=
base
-
reach
tap
setting
in
positive
-
sequence
ohms
ZR
=
relay
-
reach
in
positive
-
sequence
ohms
To
set
the
relay
for
the
desired
reach
,
it
is
necessary
first
to
select
the
proper
"
Base
Reach
Tap
"
.
This
tap
should
be
the
highest
"
Base
Reach
Tap
”
that
is
smaller
than
the
desired
ohmic
reach
.
The
setting
of
the
"
Base
Reach
Tap
"
is
explained
under
the
section
titled
CONSTRUCTION
in
this
book
.
After
the
"
Base
Reach
Tap
"
is
selected
,
the
"
Percent
Restraint
Setting
"
may
now
be
chosen
to
produce
the
required
relay
reach
.
OPERATING
TIME
Operating
time
is
a
function
of
the
length
of
line
being
protected
,
the
source
impedance
and
the
location
of
the
fault
.
Figure
9
shows
the
average
operating
time
for
a
Type
-
SLYG
81
A
relay
when
set
for
first
zone
protection
of
a
typical
100
mile
radial
transmission
line
with
a
source
impedance
equivalent
to
a
25
mile
line
.
Figure
10
shows
the
average
operating
time
for
the
same
line
when
the
relay
is
set
for
second
-
zone
protection
.
8
Courtesy of NationalSwitchgear.com

GEK
-
49813
SENSITIVITY
Sensitivity
is
defined
as
the
steady
-
state
rms
voltage
or
current
(
at
the
relay
terminals
)
required
for
a
particular
quantity
to
pick
up
the
relay
if
all
quantities
are
in
the
optimum
phase
relationship
.
The
nominal
sensitivities
for
the
sign
in
the
SLYG
81
A
relay
are
as
follows
:
Polarizing
#
1
Sensitivity
(
Quadrature
Polarizing
)
Sensitivity
is
10
%
of
rated
voltage
Polarizing
#
2
Sensitivity
Sensitivity
is
1.25
volts
(
-
VQ
+
CKQIOZRO
)
1
.
2
.
3
.
Overcurrent
Supervision
Sensitivity
IOZRO
3
|
0
0.2
—
amperes
FOTZRI
=
3
ohms
,
3
!
Q
=
0.2
ZRI
Operate
Circuit
Sensitivity
4
.
See
Figure
11
for
sensitivity
in
terms
of
V
|
_
N
(
%
T
)
100
To
determine
current
sensitivity
,
the
ratio
of
lo
to
l
0
must
be
known
or
assumed
,
and
the
ratio
of
Zoi
_
to
Zu
_
must
be
known
.
The
current
sensitivity
can
then
be
determined
from
the
formula
:
(
|
0
-
IQ
)
ZRI
+
IQKQZRO
=
0
J
_
6
1
-
X
where
actual
reach
nominal
reach
X
=
For
example
,
if
l
0
=
3
loand
KOZRO
=
3
ZRI
then
2
/
3
l
0
ZRI
+
I
0
ZRI
=
0.16
1
-
X
if
X
=
0.8
,
5
/
3
I
0
ZRI
=
0
J
6
=
0.8
1
-
.
8
For
ZRI
=
3
ohms
,
10
=
0.16
amperes
L
=
0.48
0
ZRI
BURDENS
The
potential
-
circuit
burden
per
phase
at
69
volts
rms
line
-
to
-
neutral
voltage
is
as
follows
:
0.2
volt
-
amperes
0.17
watts
0.10
vars
Q
Courtesy of NationalSwitchgear.com

GEK
-
49813
The
impedance
of
each
current
circuit
,
measured
at
its
rated
current
,
is
shown
in
Table
IV
below
.
The
values
are
given
in
ohms
.
TABLE
IV
5
AMPERE
RATED
RELAY
1
AMPERE
RATED RELAY
PHASE
GROUND
PHASE
GROUND
Z
0.030
0.018
0.210
0.160
0.027
R
0.018
0.200
0.150
0.013
X
0.002
0.065
0.050
The
overall
current
drains
of
the
DC
control
-
power
input
(
Studs
19
and
20
)
are as
follows
:
RATED
VOLTAGE
IN
DC
VOLTS
RELAY K
2
INPUT
CURRENT
IN
MILLIAMPERES
Dropped
Out
Picked
up
Dropped
Out
Picked
Up
Dropped
Out
Picked
Up
Dropped
Out
Picked
Out
48
200
48
315
110
90
110
175
125
80
125
155
250
260
t
260
t
250
t
Input
to
studs
A
and
C
of
external
pre
-
regulator
.
CIRCUIT
DESCRIPTION
The
internal connections
for
the
Type
-
SLYG
81
A
relay
are
shown
in
Figure
2
.
The
terminal
numbers
at
the
top
and
bottom
OT
this
diagram
represent
the
external
connections
to
the
relay
.
The
external connections
can
be
grouped
as
shown
in
Table
V
.
TABLE V
EXTERNAL
CONNECTIONS
TERMINAL
NUMBERS
1
through
8
DESCRIPTIONS
AC Current
Inputs
Contact
(
Other
End
Connected
to
#
19
)
Surge
Ground
Contacts
with
Targets
AC
Potential
Inputs
DC
Control
Power
Input
9
10
11
through
14
15
through
18
19
through
20
10
Courtesy of NationalSwitchgear.com