GE SFF201A User manual

GEK-90636D
INSTRUCTIONS
Static Frequency Relays
SFF2O1A, B
SFF2O2A, B
SFF2O4A, B

GEK-90636
rrabl
of
Contents
Page
Description
3
Application
4
Under
Frequency
4
Rate
of
Change
5
Over
Frequency
5
Load
Restoration
6
Specifications
7
DC
Control Voltage
7
AC Control
Voltage
7
AC
Measurement
Input
7
Settings
7
Environmental
7
Ratings
8
Burden
8
Contact Ratings
8
Settings
8
Displays
9
Functional
Description
9
Construction
10
Receiving,
Handling
and
Storage
10
Acceptance
Tests
10
General
10
Visual
11
TestEquipment
11
General
Testing
Considerations
11
Relay
Outputs
11
Tests
12
Over
Frequency
Relay
Tests
12
Over
Frequency
Test With
Variable
Frequency
Generator
12
Over
Frequency TestWith
Single
or Line
Frequency
13
Under
Frequency
Relay
Tests
14
Under
Frequency Test
With
Variable
Frequency
Generator
14
Under
Frequency Test
With
Single or
Line
Frequency
14
Rate
of
Change
for
Multiple
Setpoint
Models
Only
15
Rate
of
Change
Test
for
Variable
Frequency
Generators
15
Rate
of
Change Test
for
Single
or
Line
Frequency
16
Restore
Relay
Tests
16
Restore
Test
With
Variable
Frequency
Generator
17
Restore
Test
With Single
or
Line
Frequency
17
Installation
Procedure
17
Surge
Ground
18
Electrical
Tests
18
Settings
18
Trouble
Shooting
18
Servicing
19
Periodic
Checks
and
Routine
Maintenance
19
Renewal
Parts
20
Cover Photo:
8043796
2

GEK-90636
DESCRI PTION
The type SUP relays are
digital frequency relays that measure the system
frequency.
Three versions of the 5FF are available providinç one,
two,
or four
frequency setpoints. Each
S
the frequency measuring elements
is independent, and
can
be
independently
set
for under frequency,
over frequency, or restore operation,
and has
I form
C output contact. Each element may be set for any freQuency over the
ranse
of 40 to
79.9
Nz in 0.1 Hz steps in the SFF2O(-)A and 0.01 Hz
steps
in the
SFF2O(-)B. If a frequency setting outside of the acceptable range is made, that
frequency will be prevented from operating.
A simple rate-of-change (ROC) feature can
be
enabled on the multi-frequency
models. When this feature is enabled, an
output will be
produced
at the higher set
frequency if the next lower frequency setpoint is
reached
before
the timer associated
with the higher
set
frequency can time
out.
For example,
assume that a two setpoint
relay is set to operate at 59 Hz with an
0.75
second delay. and
at 58
Hz with
a I second
delay.
If 58 Hz is reached 0.5 seconds after 59 Hz is reached, the
output
relay
associated with the
59
Hz setting
will operate at that time rather than waiting until
the full 0.75 seconds has expired. Similar performance can
be
obtained between the
second and third setpoints and between
the third and fourth setpoints in the four
setpoint relay.
The minimum operating time for an under
frequency, over frequency, or restore
output to occur is 3 cycles. In addition, an adjustable timer is provided for each
frequency setpoint wherein
a delay can be added to the output. When used in the
under frequency or over frequency mode this time is
used to delay the output,
whereas it is used
to
prolong the
output
when the function is
used in the
restore
mode.
Timer ranges are shown below:
Mpdel Timer
Ranae SteDs
Sfl20(-)A:
0
to
1.55
seconds
.05
second
SF’F20(-)B: 1.0 to 255 milliseconds 1 millisecond
0.lto 25.5
seconds 0.lsecond
The
AC undervoltage cutoff function operates to block all outputs whenever the
input voltage is less than the undervoltage
cutoff setting. The function has a dropout
time
Sapproximately one-half
(1/2)
cycle and a pickup time dapproximately one (1)
cycle. The function
is adjustable over the range 535 to 95 percent inS percent
stçps.
Note that the percentage is based on 120 volts,
the
nominal rating
d’the relay. For
example, if the input voltage is 110 volts, and the cutoff level is
set to 50 percent,
cutoff will occur at 60 volts (50 percent of 120) rather than 55 volts (50 percent of
These
instructions do not
purport
to cover all details or variations in equipment nor to prouide for
evely
possible contingency to be met in connection with installation, operation or maintenance.
Should funher
information
be desired or should particular problems arise
which
are
not covered
sufficiently
flu’ the purchaseri 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
vaiy gnat4y.
a

GEK-90636
The
relays
can
be
powered
from
either
a
DC
or
AC
source.
External
connections
to
the SFF2O1,
SFF2O2
and
SFF2O4
relays
can
be
seen
in
Figures
1, 2
and
3,
respectively.
Table
I
summarizes the
models
available.
Table
I
Model
Case
Set
SFF
Size
Points
201
S2
1
202
M2
2
204
M2
4
APPlICATION
The
SFF
series
of
frequency
relays
can
be applied
wherever
an extremely
stable
device
is
required
for
the
accurate
detection
of
under
frequency or
over
frequency
conditions.
Under
Krequency
The
under
frequency trip feature
of
the
SFF
relays may
be
used
in load
conservation
schemes where
accuracy and
repeatability
of frequency
measurement
is
important. If
a system
disturbance
results
in
loss of
generating
capacity
such
that
load
exceeds
generation,
system frequency
will
start
to
decay
and
the
system
may
be
in
danger
of collapsing.
Under
frequency
relays
distributed
around
the system
can
be
used
to
detect
this
condition
and
to
disconnect selected
system
load
to
compensate
for
the
loss
of generation.
Sufficient
load
must
be
disconnected
to
enable the remainder
of the
system
to
recover to normal,
or
near
normal
frequency. In
this
way,
restoration
of the
entire
system
will
be facilitated.
An
overall
load
conservation
scheme
can
be
arranged
to
trip
off
selected
load
in
different
ways:
a.
Disconnect blocks
of
load
in
several
steps
with
each
step
occurring
at
a
successively lower
frequency.
b.
Disconnect
blocks
of
load
in
several
steps
on
a time
basis
at
one
frequency
level
so
that
some
load
is disconnected
as each
time
step is
reached.
c.
Any
combination of
the
above.
Each
frequency
measuring
element
in
the
SFF compares
the
period
of
each
cycle
of
the
voltage wave
against
a
crystal
reference and
requires three
successive
cycles
of
under
or over
frequency
before
the
delay
timer
is
started. If
the
input
voltage
wave is
distorted
so
as
to
affect
the period
of
the
wave,
and
if
this
distortion
persists
for the
total
time
setting, it
is
possible
for
the
relay
to make an
incorrect
measurement.
Longer
time delay settings
will
make
this less
likely
to occur.
On
the other
hand,
if
the
frequency
exceeds
the
setting
for
at
least
one cycle
after
the delay
timer
is
4

GEK-90636
started,
arid
before
the
time
delay
is
reached,
the
timer
will
be
immediately
reset
and
a
new
measurement
will
be
started.
An
important
consideration
in
the
application
of
frequency
relays
is
the location
of
the potential
source
from
which
the relay
makes
its
measurement.
It
is
generally
not
good
practice
to
supply
a
relay
from
a
potential
source
that
is
connected
to
one
bus
section
and
use
that
relay
to
disconnect
load
on
another
bus
section.
For
example,
the
voltage and
frequency
of
circuits supplying
motor
load
do
not
go
to
zero immediately
when
the
circuits
are
de-energized.
Rather,
both
the
voltage
and
the
frequency
decay
to
zero and
often
at
different
rates depending
on
the
characteristics
of
the
circuit
and
the
load.
A
frequency
relay
connected
to
such
a
circuit
could
produce
an
output
for
this
condition
if
the
voltage
stays above
the
voltage cutoff
setting
for
the
time delay
setting
(if
any).
If
the
relay
is
connected
to
disconnect
load
on
a
separate
bus section,
then
this load
will
be
inadvertently
disconnected.
A
substation
which
has
a
large
amount
of
motor
load
may
present
a
problem
of
time
coordination
in
load
shedding
applications.
If the
transmission
sources
to
the
substation
are tripped
out,
the
motor
load
would
tend
to
maintain
the voltage
while
the
frequency decreased
as
the motors
were slowing
down.
This
slow
decay
of
voltage
combined
with
a
fast
operating
under
frequency
relay
may cause
the
motor
breakers
to
trip
and
lock
out
unnecessarily.
In
an
unattended station,
restoration
of
the
motor
load would
not
then
be accomplished
by
simply
reenergizing
the transmission
sources.
‘This problem
could be
avoided
by
coordinating
the
settings
of
the
time
delay
of
the
under
frequency
trip
and
the level
of
the
undervoltage
cutoff
function.
The
SFF
relay may
also
be
used
in
an
industrial
installation
that
is
tapped
off
of
a
power company
transmission
circuit
that utilizes
high
speed
automatic
reclosing.
For
faults
on
the line,
both
ends of
the
line
will
be
tripped.
This
will
be
followed
by
a
high
speed
reclose.
It
is
important
for
the industrial
load
to
be
disconnected
prior
to
the
reclosure
to
prevent
damage
to
motors
andlor
generators
that may
have
slowed
down
during
the
interruption.
An
SFF
relay
at
the plant
could
be
used
to
detect
the
drop
in
frequency
that might
occur
during
the
time
that
the
transmission
line
is
open.
The
relay
could
be
used to
trip the
incoming
breaker
to
the
plant
to
separate
it
from
the
power
system
before
reclosing
takes
place.
Each
application
will
have
to be
analyzed
to
determine
the
amount
of
frequency
decay,
if
any,
that
will
occur
during
the
open circuit
period.
Rate
of
Change
The
rate
of
change
feature
is
available
only in
multi-setpoint
models
of
the
SFF
relays,
and
is
usable
only
between
two
adjacent
setpoints;
i.e., Fl
and
F2, F2
and
F3
or
F3
and F4.
This
feature
will
allow
load
to
be
shed
faster
if
the frequency
decays
at
a
rate
faster
than
was
anticipated
when
the
delay
timer
settings
were
determined.
The
rate of
change
feature
is
enabled
by
setting
the
appropriate
ROC switch
to
the
IN
position.
Over
Frequency
The
over
frequency
function
may
be
used
anywhere
that it
is
desired
to
detect
an
over
frequency
condition.
For
example,
it
can
be
used
to
protect
a
generator
against
operation
at
frequencies
above
rated
speed
that
could
be
caused
by an
inadvertent
load
rejection.
Another
possible
application
of
the over
frequency
function
is
in
schemes
to
be
used to
protect
a
generator
against
accidental
energization
at
sub
synchronous
speeds
or
on
turning
gear.
In
such
schemes
the over
frequency
function
would
be
used
to
remove
supplemental
protection
that
is
required
to
be
enabled
only
during
off-line
operation.
5

GEK-90636
CAUTION
It
should
be
recognized
when
applying
the
over
frequency
function in
this
fashion
that
a
loss of
I)C
to
the
relay
will
cause
the
output
relay
to
reset,
thus
enabling
the
associated
off-line
protection.
Load
Restoration
If
a
load
shedding
program has
been
successfully
implemented,
the
system
frequency
will
stabilize,
and
through
system
control
will
recover
to
normal.
The
recovery
to
normal
is
likely
to be
quite
slow
and
may
extend
over
a period
of
several
minutes.
As
the frequency
approaches
normal
the
restore
function
in
the SFF
relay
can
be
used
to automatically
begin
the
load
restoration
process.
The
amount
of load
that
can
be
restored
is determined
by the
ability
of
the
system
to
serve
it. The
availability
of
generation, either
locally
ol- through
system
interconnections,
determines whether
or not
the
shed
load
can
be successfully
restored.
A load
restoration
program
usually
incorporates
substantial time
delay,
which
must
be
provided
by
a timer
external
to
the
SFF
relay.
The
amount
of
time
delay
to
use
is
related
to
the amount of time
required
to
add
generation
or
to close
tie
lines
during
emergency
conditions.
Also,
both
the time
delay
and
the
restoration
frequency
setpoints
should
be
staggered
so that
all
of the
load
is
not
reconnected
at the
same
time.
Reconnecting loads
on
a distributed
basis
also
minimizes
power
swings
across
the
system
and
thereby
minimizes the
possibility
of initiating
a
new
disturbance.
Since
the
restoration timers
will
be
set
for
long
time
delays,
it
is
essential
that
they
do
not
reset
as
a result
of
transient
system
frequency
oscillations
that
may
momentarily
reset
the
restore
output
function. For
this
reason,
the
restore
function
is
provided
with
an
adjustable
time
delay
reset
before
the contacts
change
state
whenever
the
function
is
subjected to a
frequency
change
from
above
the
setpoint
to
below
the setpoint.
This
delay
is adjustable
and should
be
kept
very
brief,
only
long
enough
to
ride over
momentary
under
frequency conditions.
The
restore
frequency
setting
of the
function
will
most
likely
be
at
or
very
close
to
rated
frequency. If the
continuous
variations in
normal
frequency
are such
that
the
restore
function
output
relay
will
pick
up and
drop
out
continually,
the
life
of the
relay
may
be
shortened. To
prevent
this,
a
contact
converter
designated
CC
is
provided
to control
the
restore
output.
CC
is to
be energized
by an
external
device
after
load
shedding has
occurred
and
when
it is
desired
to
restore
load.
CC
should
be
kept
energized
until
all
of the
load
that
was
shed
has
been
restored
at
which
time
it
should
be
de-energized.
In
this
way,
the
restore
output
relay
will
only
be
operated
after
an
under
frequency
condition
has
been
detected and
until
the
load
that
was shed
has
been
restored. During
normal
frequency conditions,
CC
will
be
de-energized
and
the
restore
function
will
not operate
due to
minor
changes
in
frequency.
6

GEK-90636
SPECIFICATIONS
DC
Control
Voltage
Nominal
48, 110,
125,
220,
250
Minimum
37
Volts
Maximum
280 Volts
AC Control
Voltage
Nominal
110-120
Vrms
Minimum
45
Vrms
Maximum
132
Vrms
AC Measurement
Input
Nominal
120
Vrms
Minimum
42
Vrms
(35%
of
nominal)
Maximum
132
Vrms
(110% of
nominal)
Settings
Frequency
SFF2O(-)A:
Setpoint
40.0
to
79.9
Hz in
0.1
Hz
steps
SFF2O(-)B:
Setpoint
40.0 to
79.9 Hz
in 0.01
Hz
steps
Repeatability
±0.002
Hz
Timing
SFF2O(-)A:
Setpoint
0
to 1.55
seconds
in 0.05
second
steps
SFF2O(-)B:
Setpoint
1 to
255
milliseconds in 1
millisecond steps
Setpoint
0.lto 25.5
seconds in
0.1
second
steps
Repeatability
± 3%
Undervoltage
Setpoint
35% to
95%
in 5%
steps
based
on l2OVrms
nominal
Setpoint
Accuracy ±5%
Repeatability
±3%
of
setting
from
35% to
90%
Rate
of
change
(multi-setpoint
models
only)
Frequency
1
to
frequency
2:
IN
or
OUT
Frequency
2
to frequency
3:
IN
or OUT
Frequency
3 to
frequency
4:
IN
or OUT
Environmental
Operating
-20°C
to
+55°C
95% relative
humidity
(noncondensing). Note
that
the
unit
will
not malfunction,
nor
be damaged,
in
ambient
up to
+
65°C
Storage
-40°C
to + 75°C
95%
relative
humidity
(noncondensing)
Surge
ANSI
C37.90
(SWC
and Fast
Transient)
IEC 255
GE RFI
7

GEK-9063
RATINGS
Burden
Table
II
Burdens
Model
Case
Set Power Supply
Measurement
SFF
Size
Points
DC
AC
AC
________
VA
VA
48
125
250
120
201 S2
1
3.2
3.5 6.3 8.1
1
202
M2
2
4.9
5.2
8.0
10.6
1
204
M2
4
8.4 8.7
11.5
15.7
1
Contact
Ratings
Make
and carry
30
amps
for
1 second.
DC
Break
60
Watts
Resistive
Break
25
VA
(40
ms
L/R)
AC
277
Volts
maximum
5
Amperes
Target
supervision
unit
0.1
amp
operate
level
with
less
than
0.6
volt
drop
at 30
amps.
SWFTI
NGS
The
following
settings,
which
must
be
set
in
each application,
are
made
from
the
front
of
the
relay
without
the
need
for
pulling
boards
or
removing
the
nameplate.
It
is
only
necessary
to remove
the
front
cover
from
the relay.
Frequency
A
three
or
four digit thumbwheel
switch
on
the front
panel
allows
the
frequency
of each
setpoint
to
be
set.
Note:
if
a
setting
is
made
outside
of the
stated
range,
that
frequency
setpoint
will
be
prevented
from
operating.
Function
A
three
position
slide
switch
permits
the
choice of
under,
over,
or restore
modes of
operation.
When
the
restore
mode
is chosen
the timer
is switched
to
dropout
delay and
the contact
converter
input
is enabled.
Rate
of
Change
(Multi
frequency
models
only)
A
two position
recessed
switch
selects
the
rate of
change
function.
This
function
is
only
valid for
under
frequency
operation.
It
is
disabled
when
over
frequency
or
restore
modes
are
chosen.
Time
Delay
An
array
of
two-position
toggle
switches
allows
setting
the
output
delay.
The
setting
is equal
to
the
sum of
the
switches
in
the
UP
position.
Voltage
Cutoff
An array
of
two-position
toggle
switches
calibrated
in 5%
steps
is
used
to choose
the
undervoltage cutoff
level.
The
cutoff
setting
is equal
to
the
sum
of
the
switches
in the
UP
position.
8

GEK-
90636
DISPLAYS
jp
The
trip indicators
are
red LED’s
which are supervised
by
the
passage
of trip
current.
One
is
provided
for
each
tripping
element.
Table
HI
Model
Target
Description
201
Fl
Frequency
1
output contact
operated
202
Fl
Frequency
I
output
contact operated
ROC
Rate of
change
caused
Fl
contact
to
operate
F2
Frequency
2
output
contact
operated
204
Fl
Frequency
1
output
contact
operated
ROC
Rate
of
change
caused
Fl
contact
to
operate
F2
Frequency
2
output
contact
operated
ROC
Rate
of
change
caused
F2
contact
to
operate
F3
Frequency
3
output
contact
operated
ROC
Rate
of
change
caused
F3
contact
to
operate
F4
Frequency
4
output
contact
operated
Test
Amber
LED’s
light
to indicate
when
the
frequency
detection
circuit
has
an
output and
if an output relay
is
energized
(TB).
In
Service
A normally
lit green
LED indicates
the
regulated
DC
and
start-up
circuity
are
operational.
FUNCTIONAL
DESCRIPTION
The
potential
source
connected
to studs
5 and 6
is
stepped
down
to
6.9 VRMS
filtered
and converted
to a
square wave.
It
is
this square
wave
that
is
measured
by
the frequency element.
The frequency
measuring
circuit
compares
the
period
of the
incoming
square
wave
against
a
crystal
reference.
If
the source
frequency
differs
from
the
setpoint
for
more
than
three
consecutive periods
or cycles
the circuit
gives
an output. If
the
under
voltage supervision
has not
operated
this output
starts
a time
delay
(which
can
be
set
to
0)
which in
turn drives
the
output
contact.
The
rate of
change
feature if
selected
will
bypass
the time
delay if
the
next lower
frequency
element
has
operated.
The
rate of change
path
is
F4
to F3,
F3
to F2,
and F2
to Fl. Therefore when
the
frequency
settings
are made,
F4
should
be
less
than F3,
etc.
This does
not
preclude
setting
one element
for
restore, another
for
over, and
the remaining
two
for under
in
a
four
frequency relay.
It is
only
important
that the under
frequency
elements
be
adjacent
(F1-F2,
F2-F3,
F3-F4)
if rate
of
change is
desired. Block
diagrams
of
each
model can
be
found
in
Figures
4,
5
and
6. Internal
connection
diagrams
for
each
model
can be
found
in
Figures 10,
11 and
12.
9

GEK-90636
CONSTRUCTION
The components
of
the
relay
are
mounted
on
a cradle assembly
that
can easily
be
removed
from
the
relay
case.
The
cradle
is
locked
in the
case
by
latches
at
the top
and
bottom.
The
electrical
connections between the
case blocks
and
the cradle
b1ocks
are
completed
through
removable
connection
plugs to
permit
testing
the
relay
in
its
case.
The
cover is
attached
to the
front
of
the case
and
includes
two
interlocking
arms
that
prevent
the cover
from
being
replaced
until
the
connection
plugs
have
been inserted.
The
case
is
suitable
for semi-flush
mounting
on
panels.
Hardware
is
available
for
all
panel
thicknesses
up
to two
inches.
A
panel
thickness of 1/8
inch
will
be
assumed
unless
otherwise
specified
on the
order.
Outline
and
panel
drilling
dimensions
for
the
SFF2O1
are
shown
in
figure
8 and
for
the
SFF2O2
and 204
figure
7.
The
printed
circuit
boards are
mounted
behind
the nameplate
and
can
be accessed
by
removing
the
four screws
securing
the
nameplate.
The
boards
are mounted
horizontally in
guides.
Each
board
is labeled
to
correspond
to
a given location.
Use
GE
part number
286A2847P1
card
puller
or other
suitable means
to
remove
the
circuit
boards.
If
you
do
not have
a
card
puller,
be
careful
not
to damage
or
bend
any
components when removing the
boards.
The
output
relays
are
mounted
in
sockets
on
a
board
fixed to
the
back
of
the
cradle.
If
a relay requires
replacement
unclip the
retaining
wire
and pull
the
relay
out
of
the
socket.
The
input
transformer
is
mounted
on
the bottom
plate
of the
relay
cradle.
RECEIVING,
HANDLING
AND
STORAGE
This
relay
contains
electronic
components
that
could
be
damaged
by
electrostatic
discharge
currents if
those
currents flow through
certain
terminals
of
the
components.
The
main
source
of
electrostatic
discharge
currents
is
the
human
body,
and the
conditions
of low humidity,
carpeted
floors
and
isolating
shoes
are
conducive
to the
generation
of
electrostatic
discharge
currents.
Where these
conditions
exist,
care should
be
exercised
when
removing
and
handling
the
modules
to
make
settings
on
the
internal
switches.
The
persons
handling
the
module
should
make
sure
that
their body
has
been
discharged, by touching
some
surface
at
ground
potential,
before
touching
any
of
the
components
on
the modules.
These
relays,
when not
included
as
part
of
a control
panel,
will
be
shipped
in
cartons
designed
to protect them
against
damage.
Immediately
upon
receipt
of
a
relay
examine
it
for
any
damage
sustained in
transit.
If
damage
resulting
from
handling
is
evident,
file a
damage
claim
at
once with
the transportation
company
and
promptly
notify
the
nearest
General
Electric Sales Office.
The
relays
should
be stored
in
their
original
cartons.
If
the relays
are not
to
be
installed
immediately, and
in
a
place
that
is free from
moisture,
dust
and metallic
chips.
ACCEPTANCE
TESTS
General
The
relay should
be examined
and tested
upon
delivery
to
insure
that
no
damage
has been
sustained
in
shipment
and
that
the
relay
is
functioning
correctly.
10

GEK-90636
Visual
Remove
the relay
from
its
case
and check
for
signs
of physical
damage
such
as
broken
or
cracked
parts.
CAUTION:
Every
circuit
in the
drawout
case
has an
auxiliary
brush.
it is
especially
important
on circuits
with shorting
bars
that
the
auxiliary
brush
be bent
high
enough
to
engage
the
connecting plug
or
test
plug
before
the
main
brushes
do.
This
will
prevent
the secondary circuits
from
being
open-
circuited
during
insertion
of the
connection
plug.
A drawout
case
relay
may
be
tested
without
removing
it,
from
the
panel,
by using
a
12XLAI3A
test
plug.
This
plug
makes
connection
to
the relay
only
and
does
not
disturb
any
shorting
bars
in
the
case. The
12XLA12A
test
plug
may
also
be
used.
Although
this
plug
allows
greater
flexibility,
it
requires
shorting
jumpers
since
connections are made
to
both
the
relay
and
the external
circuits.
‘Pest Equipment
1
DC
voltage
source
rated
at 48V
to
250V
with
less
than
5%
ripple
2.
Variable
frequency
generator
or
line
frequency
rated
at
48
to
l2OVrms,
40
to
70
hertz
3.
Limiting
resistor,
or load
box for
trip
target
indicator
test.
Rated
from
100Q-
3KQ,
25
Watts.
General
Testing
Considerations
The
relay
can
be
tested
with
a
variable
voltage/frequency
generator
or with
the
line
frequency.
The acceptance
test
have
taken
into account both
contingencies.
Each
test
has
a section
for line
frequency testing
and or
for
variable
frequency
generators.
When
utilizing
variable
frequency/voltage
generators
refer
to the
test equipment
manufactures
manual
for specific
operation
instructions
of the
test
apparatus.
Testing
with
line
frequency
requires
that
the frequency
setpoints
of
the
relay
be
set
above
or
below
the
line frequency
depending
on
the
fault
being
simulated.
Relay
Outputs
Test
Targets
The
test
target
LEDs
are labled
Test
Fl,TB
to
F4,TB,
see
figure
17,
19
(front
panels).
The
test
targets
indicatEWe
status
of
the
output
relay
(TB)
and
the
frequency
measuring
element
(F-).
The
“F”
test
indicator
will
light
when
the
frequency
deviates
from
the
setpoint
for
3 consecutive
cycles.
The
“TB”
indicator
lights
when
the
timer
is producing
an output
to
operate
the
output
relay.
Trip
Targets
The trip
target
LEDs
are labeled
F1,RC
to F4,RC.
They
will
latch
“on”
when
the
relay trips
and
there
is over
lOOma
through
the normally
open
contacts.
They
are
reset
with
the
target
reset
switch
or
by
the
removal
of the
relay
power.
11

GEK-90636
Relay Contacts
The relay
contacts
consist
of normally
open
(NO)
and normally closed
(NC)
contacts
for
each
of
the
frequency
measuring
units.
Tests
For
the following
test.s
refer to figure
9 for
test
connections, and
to figure
17
and
20
for
the front
views
of
the
SFF2O1, and 204
respectively.
For
the SFF202
refer
to the
SFF204
front
view.
Test the
relay in
accordance with
the function
it is
set
for.
Such
as
Over
Frequency,
Under
Frequency,
Rate
of
Change
or
Restore.
Note: The
trip
LEDs
will only
light and
seal in if lOOma of
current flows
through the
output
contacts.
Over
Frequency Relay
Tests
The relay will
trip when the
frequency under
test exceeds
the frequency
setpoints
for
more than
three cycles.
Table
IV
________________
Switch
Settings
Set
Under
Point
t
Frequency
Mode ROC
Time
Voltage
Delay
Cutoff
SFF2O1
Fl
5Oor6Ohz
over
-
1.5sec
35%
SFF2O2
Fl
50 or
60hz over
out
1.5sec
35%
F2
50
or 60hz
over
- 1.5sec
SFF2O4
Fl
50 or
60hz over
out l.5sec
35%
F2
50 or
60hz
over
out
1.Ssec
F3
50
or
60hz
over out
1.5sec
F4
50
or 60hz over
- 1.5sec
T
The
relay can
be tested
at other frequencies
if
desired.
To
do
so,
set
the
frequency
and adjust the
inputs based on
that setting.
Over Frequency
Test
With Variable
Frequency
Generator
1.
Apply
the rated supply voltage
between stud(1)
and
stud(2)
(either
polarity).
2.
Set
the frequency
generator
at
(0.5hz)
below
the setpoints.
For example,
set
the frequency
to 59.5hz
for 60hz
and 49.5hz for
50hz
rated setpoints.
Apply the
frequency
source
at
115
Vrms between
stud(5)
and
stud(6).
Then increase
the
frequency
(0.5hz) above
the setpoint.
Maintain
the
frequency
at
the
higher
setting
for
3 cycles
plus 1.5sec
to produce
an output.
Verify
that the
following
occurs
during
the
over
frequency. The
test target
LEDs
“Fl”
to
“F4” light.
The “TB”
test targets
and
the
trip target LEDs
“Fl”
to
“F4”
light
after the
1.5
second
time delay.
And
the output
relay contacts
have
tripped,
as
indicated by
the trip
targets.
12

GEK-90636
3.
Remove
the
input
test
frequency, and
note
that
the
contacts
and LEDs
have
dropped
out.
4.
Reset the
target
LEDs.
5.
Remove
the
supply
voltage.
6.
Set
the
undervoltage
switch
setting
to
95%,
and
repeat
the
above
test
starting
at
step
1.
With
the
undervoltage
set
at
95%
there
should
be
no
trips,
or
target
LEDs
on
during
the
over
frequency.
The
undervoltage
cutoff
will
disable
all
outputs.
Over
Frequency
Test With
Single
or
Line
Frequency
Before
applying the
line
or
single
frequency
source,
set
the
frequency
setpoint(s)
(0.5hz) below
the
frequency
input
that
you
use.
Such
as
59.5hz
for
60hz
and
49.5hz
for 50hz
rated
line. This
simulates
an
over
frequency.
1.
Apply
rated
supply voltage
between
stud(1)
and
stud(2),
non
polarity
sensitive.
2.
Apply
the
test
line
frequency
at
ll5vrms
between
stud(5)
and
stud(6).
As
the
line
frequency
is
applied
verify
that
the
test
target
LEDs
“Fl”
to
“F4”
light,
the
“TB”
test targets
and
the
trip
target
LEDs
“Fl”
to
“F4”
light after
the
1.5
second
time
delay
setting.
And
the output
relay
contacts
have
tripped,
as
indicated
by
the
trip
targets.
3.
Remove
the
input
test
frequency,
and
note
that
the
contacts and
test
LEDs
have dropped
out.
4.
Reset
the
targets.
5.
Remove
the
supply
voltage
6.
Set
the
undervoltage
switch
setting
to
95%,
and
repeat
the
above
test
starting
at
step
1.
With
the
undervoltage
set
at
95%
there
shouki
be
no
trips,
or
target
LEDs
during the
over frequency.
The
undervoltage
cutoff
will
disable all
outputs.
Table
V
Switch
Settings
Set
T
Under
Point
t
Frequency
Mode
ROC
Time
Voltage
Delay
Cutoff
3I’F1J1
Fl
50 or
60hz
under
-
l.5sec
35%
SFF2O2
Fl
50
or
60hz
under
out
l.5sec
35%
F2 50
or 60hz
under
-
l.5sec
SFF
204
Fl
50
or 60hz
under
out
1.5sec
35%
F2
50
or
60hz
under
out
l.5sec
F3
50
or
60hz
under
out
1.Ssec
F4
50
or 60hz
I
under
l.5sec
.—.
I
-
---
-
-I
—
r
The
relay
can
ne
tested
at
other
frequencies
if
desired.
To
do
so,
set the
frequency
and
adjust
the
inputs
based
on
that
setting.
13

GE
K-90
636
Under
Frequency
Relay
‘l’ests
rphe
relay will
trip
when
the
frequency
under
test
is
below
the
setpoint(s)
for
more
than
three
cycles.
Under
Frequency
Test
With Variable
Frequency
Generator
1.
Apply
rated
supply
voltage
between
stud(1)
and stud(2).
2.
Set
the
frequency
generator
at
(0.5hz) above the
setpoints.
For
example,
set
the
frequency
to
60.5hz
for
60hz
and
50.5hz for
50hz
rated
setpoints.
Apply
the
frequency
source
at
ll5Vrms
between stud(5)
and
stud(6).
Then
decrease
the
frequency
(0.5hz) below the
rated
setpoints.
Maintain
the frequency
at
the
lower
setting
to
produce
an
output.
Verify
that
the
following
occurs
during
the
under
frequency.
The
test
target
LEDs
“Fl”
to “F4”
light.
The
“TB”
test
targets
and
the
trip
target
LEDs
“Fl”
to
“F4”
light
after the
1.5
second
time
delay.
And
the
output relay
contacts
have
tripped,
as
indicated
by
the
trip
targets.
3.
Remove
the
input
test
frequency,
and
note
that
the contacts and
test
target
LEDs
have
dropped
out.
4.
Reset the
targets.
5.
Remove
the
supply
voltage.
6.
Set
the
undervoltage
switch
setting
to
100%,
and
repeat
the
above
test
starting
at
step
1.
With
the undervoltage set
at
100% there
should
be
no
trips,
or
target LEDs
during
the
under
frequency.
The
undervoltage
cutoff
will
disable
all
outputs.
Under
Frequency
Test
With
Single or
Line
Frequency
Before
applying
the
line
or
single
frequency
source.
Set
the
setpoint(s)
(0.5hz)
above
the
frequency
input
used.
This
simulates
an
under
frequency.
1.
Appiy
the
rated
supply voltage between
stud(1)
and
(2).
2.
Apply
the
test or
line
frequency
at
ll5vrms
between
stud(S)
and
stud(6).
As
the
line
frequency
is
applied
verify
that
the
test
target
LEDs “Fl”
to
“F4”
light, the
“TB”
test targets
and the
trip
target
LEDs
“Fl”
to
“F4”
light
after
the
1.5
second
time
delay
setting.
And
the
output relay
contacts have
tripped,
as
indicated
by
the
trip
targets.
3.
Remove
the
input
test
frequency,
and
note that
the
contacts and
test
target
LEDs
have
dropped out.
4.
Reset the
targets.
5.
Remove
the supply
voltage
6.
Set
the undervoltage
switch
setting
to
100%,
and
repeat
the
above
test
starting
at
step
1.
With
the
undervoltage
set
at
100%
there
should
be
no
trips,
or
target
LEDs
during
the
under
frequency.
The
undervoltage
cutoff
will
disable
all
outputs.
14

GEK-90636
Rate
of
Change
(ROC)
for
Multiple
Setpoint
Models
Only
The
rate
of
change
feature
allows
the
relay
to
trip
faster
than
its set
time
delay
if
the
frequency change
is
faster and
larger
in
magnitude
the limits set
on
successive
frequency
setpoints.
Example:
Fl
is
set
to 59.8,
F2
is
set
to
58.0,
and
the
time
delays
on
Fl
and
F2
are
1.5
seconds.
If
the
frequency
were
to
go
from
60
to
59.7hz
only
Fl
would
trip
after
a
delay
of
1.5
seconds.
But
if the
frequency
was
to change
from
60
to
58hz
in
.25
seconds
the
relay
would
trip
without waiting
for
the time
delays.
The
rate
of
change
from
Fl
to
F2
was
faster
than
the
time
delay
of
Fl.
Table
VI
________________
Switch
Settings
Set
[
F
Under
Point
t
Frequency
Mode
ROC
Time
Voltage
Delay
Cutoff
F’F2U2
El
5Oor6Ohz
under
in
1.5sec
35%
F2
50
or
60hz
under
-
0.Osec
SFF2O4
Fl
50
or 60hz
under
in
1.5sec
35%
F2
50
or
60hz
under
in 1.2sec
H
F3
I
50
or
60hz
under
in
0.8sec
F4
50 or
60hz
under
-
I
0.Osec
t
The
relay
can
be
tested
at other
frequencies
if desired.
To
do so,
set
the
frequicy
and
adjust the
inputs
based
on
that
setting.
It is
essential
that
the
trip
targets
are
enabled
by
the
lOOma
of
current
through
the
normally
open
relay
contacts
for
this
test.
Rate
of
Change
Test
for
Variable
Frequency
Generators
1.
Apply
rated
supply
voltage
between
stud(1)
and
stud(2).
2.
Set
the
frequency
generator
at
(0.5hz)
above
the
setpoints.
For
example,
set
the
frequency
to 60.5hz
for
60hz
and
50.5hz
for
50hz
rated
setpoints.
Apply
the
frequency
source
at
115
Vrms
between
stud(5)
and
stud(6).
Then
decrease
the
frequency
(0.5hz) below
the
setpoint with
zero
time
delay.
When the
frequency
has
been
reduced, verify
that
the
following
occurs. The
test
target LEDs
“Fl”
to
“F4”
and
the
“TB”s light
with
with
no
time
delay.
(The
rate
of change
has
overridden
the set
time
delays
on
the
TB
outputs).
The
“RC”
trip
targets
light
with
no
delay,
and the
trip
target
LEDs
“Fl”
to
“F4”
light
in
a
delayed
sequence according
to
their
time delay
settings.
Note:
After
1.5
seconds
all LEDs
should
be
lit.
3.
Remove
the
input
test
frequency,
and
note
that
the
contacts
and
test target
LEDs
have dropped
out.
4.
Reset the
targets.
5.
Remove
the
supply
voltage
15

GEK-90636
6.
Set the
undervoltage
switch
setting
to
100%,
and
repeat
the
above
test
starting
at
step
1.
With
the
undervoltage
set
at
100%
there
should
be
no
trips
or
target
LEDs
during the
under
frequency. The
undervoltage
cutoff
will
disable
all
outputs.
Rate
of
Change
‘Pest
for
Single
or
Line
Frequency
Before
applying
the
line
or
single
frequency
source.
Set
the
setpoint(s)
(0.5hz)
above
the
frequency
input
used.
1.
Apply
rated
supply
voltage
between stud(1)
and
stud(2),
non polarity sensitive.
2.
Apply the
test
line frequency
at
ll5vrrns
between
stud(5)
and
stud(6).
When
the
frequency
has
been
applied
verify
that
the
following
occurs.
The test
target
LEDs
“Fl”
to
“F4”
and
the
“TB”s
light
with
no
time
delay.
(The
rate
of
change
has
overridden
the
set
time
delays).
The
“RC”
trip
target
LEDs
light
with
no
delay, and
the
trip
target
LEDs “Fl”
to “F4”
light
in
delayed
sequence according
to
their
time
delay
settings.
Note:
After
1.5
seconds
all
LEDs
should
be
lit.
3.
Remove
the
input test
frequency,
and
note
that
the
contacts
and
test
target
LEDs
have
dropped
out.
4.
Reset
the
targets.
5.
Remove
the
supply
voltage
6.
Set the
undervoltage
switch
setting
to 100%,
and
repeat
the
above test
starting
at
step
1.
With
the undervoltage
set
at
100%
there
should
be
no
trips
or
target
LEDs
during
the
under
frequency.
The
undervoltage
cutoff
will
disable
all
outputs.
Table
VII
Switch
Settings
Set
Under
Point t
Frequency
Mode
ROC
Time Voltage
Delay
Cutoff
SFF’20
1
Fl
50
or
60hz
restore
-
1.5sec
35%
SFF2O2
Fl
5Oor6Ohz
restore
out
1.5sec
35%
F2
50
or
60hz
restore
-
1.5sec
SFF2O4
Fl
50
or
60hz
restore
out
1.5sec 35%
F2
50
or
60hz
restore
out
l.5sec
F3
50
or
60hz
restore out
1.5sec
F4
5Oor6Ohz
restore
-
1.5sec
t
The
relay
can
be
tested at
other
frequencies
if
desired.
To
do
so,
set
the
frequency
and
adjust
the
inputs
based
on
that
setting.
Restore
Relay
Tests
The
restore
circuit
will only
produce
an
output
ifthe contact
converter
connected
to
pins
10
and
20
is
energized.
16

GEK-90636
Restore
Test
With
Variable
Frequency
Generator
LApply
rated
supply
voltage
between
stud(1)
and
stud(2).
2.
Connect
a
DC
source
rated
at
48V
to
250V
between
stud(10)
and
stud(20). Your
power
supply
voltage
will
suffice
if
it
is
DC.
3. Set
the
frequency
generator
at
(0.5hz)
above
the
setpoints.
For
example,
set
the
frequency
to
60.5hz
for
60hz
and
50.5hz
for
50hz
rated
setpoints.
Apply
the
frequency
source
at ilSVrms
between
stud(5)
and
stud(6).
And
note
that
the
test
targets
‘Ti”
to “F4”
and
“TB”
LEDs
are
lit.
Next, decrease
the
frequency
(0.5hz)
below
the
setpoint.
The
test
target
LEDs
“Fl”
to
“F4”
will
go
out
but
the
“TB”
LEDs
will
remain
lit
(output
contact(s)
are
closed)
for
the
1.5 second
delay
setting.
4. Remove
the
input
test
frequency.
5. Remove
the
supply
voltage
6. Set
the
undervoltage
switch
setting
to
95%,
and
repeat
the
above
test starting
at
step
1.
With
the
undervoltage
set
at
95%
there
should
be
no
trips
or
target
LEDs
during
the
test.
The
undervoltage
cutoff
will
disable
all
outputs.
Restore
Test
With
Single
or
Line
Frequency
1.
Before
applying
the
line
or
single
frequency
source.
Set
the
frequency
setpoints
(0.5hz)
below
the
frequency
used.
Apply
rated
supply
voltage
between
stud(1)
and
stud(2).
Connect
a
DC
source
rated
at 48V
to 250V
between
stud(10)
and
stud(20).
Your
power
supply
voltage
will
suffice
if
it
is DC.
2.
Apply
the
test
line
frequency
at
li5vrms
between
stud(5)
and
stud(6).
And
note
that
the
test
targets
“F”
and
“TB”
LEDs
are
lit.
With
the
test
or
line
frequency
still
applied,
increase
the
frequency
setpoints
to
(0.5hz)
above
the
rated
line
frequency.
The
test
target
LEDs
“Fl”
to “F4”
will
go out
but
the
“TB”
LEDs will
remain lit
and
the output
contacts
will
stay
closed for
the
1.5
second
time
delay
setting.
3.
Remove
the input test
frequency.
4.
Remove
the
supply voltage.
5.
Set
the
undervoltage
switch
setting
to
95%,
and
repeat
the
above
test starting
at
step
1.
With
the
undervoltage
set
at
95%
there
should
be
no
trips
or target
LEDs
during
the
test.
The
undervoltage
cutoff
will
disable
all
outputs.
INSTALLATION
PROCEDURE
The
relay
should
be
installed
in
a
clean,
dry
location,
free from
dust
and
excessive
vibration.
It
should
be
mounted
on
a
vertical
surface.
The
outline and
panel
drilling
dimensions
are
shown in
figures
7
and
8.
17

GEK-90636
Surge Ground
The case
stud
should
be permanently
connected
to
ground
by
a
conductor
not less
than
AWG
No. 12
copper
wire
or equivalent. This connection is made
to
ground the
relay
case
and the surge
suppression networks
in the
relay. The surge ground
lead
should
be as short as
possible,
preferably 10 inches or less, to provide
maximum
protection
from
surges.
Figure 23 shows
a
rear view of an S2
case
illustrating the
position
of
the case
grounding
stud.
Electrical Tests
The test given
in
the Acceptance Section can be used as a guide
in
the
establishment of your procedure.
Settings
Frequency
Set the desired frequency
for each setpoint
by
pushing the +
and -
buttons on the switch.
Mode Choose
Under, Over or
Restore
operation
by a
recessed three
position
slide
switch.
Rate
of Change ON multi-setpoint models, select
IN or OUT
by a two
position slide
switch.
Time
Delay
Set
the desired time by summing the
setting
of
the toggles
in
the
UP position.
Undervoltage Set
the desired
voltage
by
summing the toggles
in
the UP position.
TROUBLE SHOOTING
CAUTION:
The
power
supply in this relay is not isolated from the incoming power.
The heat
sinks are at the incoming potential. Further the
common
of the
regulated DC is at the same
potential
as
the most
negative power
terminal
and SHOULD
NOT
BE CONNECTED TO GROUND. Make sure that test
instruments
connected to
monitor the signals
within the
relay are
suitably
isolated from ground and observe
proper
techniques to
avoid
a
shock
hazard.
The card
extender
board part number
0215B8031G1
is required
to perform these
tests.
CAUTION:
REMOVE
ALL
power from
relay before removing or inserting any
of the
printed
circuit boards or output relays.
Failure to observe this caution may
result
in
damage to
and/or misoperation
of the
relay.
18

GEK-90636
The
defective
circuit
may
be
identified
by
fo1lowin
the
procedures
outlined
in
the
following
paragraphs. The
tests
are
based
on using
line frequency
as the input
and on
a
set
of
known
settings.
Begin by
setting
the relay.
TABLE VIII
SFF
Line Fre uency
plus Mode
Rate of Under
Time
Model Fl
F2 F3 F4
Change
Voltage Delay
201
0.1
Under
50% 0.1
202 0.2
0.1
Under Out
50% 0.1
204
0.4
0.3
0.2
0.1 Under Out
50% 0.1
Refer
to figures
17
through
22 for
views
of
the relay
with
and without
a
nameplate.
The board locations are
identified
by letters
Ofl
the right
side of the cradle.
These
letters
and
the
part number
of the printed
circuit assembly
for
each location
are given
on
the
internal connections
diagrams
in figures 10,
11
and
12.
The block
diagrams
in
figures
14,
15
and 16 give voltages
and
waveforms
to be
found
at selected
points
in
the relay.
rllhe
points
are
the
connector
pin
numbers
on
the
extender
board.
The failure
of the signal to
meet the
levels shown
on
the
diagram
indicates
a failure
in that module.
The signals
should measured with
high
input impedance
instruments to
avoid
loading
the
circuits. Remember
the regulated
DC is not isolated.
A logic
low
is
a signal
with
an
amplitude
of
between
zero
and 20% of
the regulated DC
voltage,
nominally this
is 0 to
2.4
volts.
A
logic
high
is
defined
as a
signal whose
amplitude
is between 80
and 100 percent
of the regulated
DC voltage,
nominally this
is 9.6
to
12
volts.
SKRVICING
CAUTION:
REMOVE
ALL power
from relay
before removing
or inserting
any of the printed
circuit boards
or output
relays. Failure
to
observe this
caution
may
result
in
damage
to
and/or misoperation
of the relay.
When replacing
a
module
check
the part number
and location
as
shown on the
internal
connections
diagrams
in
figures
10, 11 and
12 before inserting
the module.
Perform the
acceptance tests
before returning
the
relay
to
service.
PER1O1)IC
CJ-1ECI{S
ANI)
ROUTINE MAINTENANCE
Considering the
vital
role of protective relays
in
the
operation
of a
power
system
it
is important
that
a periodic
test
program
be
followed.
It is recognized
that
the
interval
between
periodic checks
will vary
depending
upon
environment,
type
of
relay,
and the
users experience
with
periodic
testing.
Until
the user has accumulated
enough experience
to select the
test interval best
suited
to their individual
19

GEK-90636
requirements
it
is
suggested
that
the
points listed
under
acceptance
test
be
checked
at
an
interval
of
from
one
to
two
years.
RENEWAL
PARTS
It
is
recommended
that
sufficient
quantities
of
renewal
parts
be
carried
in
stock
to
enable
the
prompt
replacement
of
any
that
are broken
or
damaged.
When
ordering
renewal
parts
address the
nearest
Sales
Office
of
the
General
Electric
Company.
Specify
the
quantity
required,
name
of
the
part
wanted,
the
part
number
if
known,
and the
complete model
number
of
the
relay
for
which
the
part
is
required.
Table
IX
lists
the
part
numbers
for
the
most
common
replacement parts.
It
is
recommended
that
renewal
parts only
be obtained
from
the
General
Electric
Company.
Should
a
printed
circuit
card
become
inoperative,
it
is recommended
that
the
card
be
replaced with
a
spare.
Since the
last
edition,
changes
have
been made
in
the
following
places:
p.3,
AC
undervoltage
cutoff
range,
p.7,
Undervoltage
specifications,
p.13,
Overfrequency
Tests step
6.,
p.15,
Rate
of
Change, example,
p.17,
Load
Restoration
Tests,
steps
6
and
5
respectively,
p.21,
Part
number
of SFF2O1
Power Supply.
20