ABB HCB-1 Manual

A
»
11
mv
ABB
Power
T
&
D
Company
Inc
.
Relay
Division
Coral
Springs
,
FL
33065
Instruction
Leaflet
I
.
L
41
-
971.31
-
Type
HCB
-
1
Pilot
Wire
Relay
System
Effective
November
1988
Supersedes
I
.
L
41
-
971.3
K
dated
August
1985
sfc
Denotes
change
since
previous
issue
CAUTION
2.1
Sequence
Filter
The
sequence
fflter
consists
of
a
three
-
legged
iron
core
reactor
and
a
set
of
resistors
designated
R
1
andRO
.
The
reactor
has
three
windings
;
two
primary
and
a
tapped
secondary
winding
,
wound
on
the
center
leg
of
a
“
F
’
type
of
lamination
.
The
secondary
taps
are
wired
totheA
,
BandCtapconnectionsinfrontofthereiay
.
R
0
consists
of
three
tube
resistors
with
taps
wired
to
the
F
,
G
and
H
tap
connections
in
the
front
of
the
relay
.
Before
putting
protective
relays
into
service
,
remove
all
blocking
which
may
have
been
inserted
for
the
purpose
of
securing
the
parts
during
ship
-
ment
,
make
sure
that
all
moving
parts
operate
freely
,
inspect
the
contacts
to
see
that
they
are
clean
and
close
properly
,
and
operate
the
relay
to
check
the
settings
and
electrical
connections
.
1
.
APPLICATION
2.2
Saturating
Transformer
The
type
HCB
-
1
relay
is
a
high
speed
pilot
wire
relay
designed
forthe
complete
phase
and
ground
protection
of
two
and
three
terminal
transmission
lines
.
Simultane
-
ous
tripping
of
the
relay
at
each
terminal
is
obtained
in
about
20
milliseconds
for
all
faults
.
A
complete
installa
-
tion
for
a
two
terminal
line
consists
of
two
relays
,
two
insulating
transformers
,
and
an
interconnecting
pilot
wire
circuit
.
For
a
three
terminal
line
,
three
relays
,
three
insulating
transformers
,
and
a
wye
-
connected
pilot
wire
circuit
with
branches
of
equal
series
resistance
are
required
.
The
output
of
the
sequence
filter
connects
to
the
primary
of
a
two
-
winding
saturating
transformer
.
The
primary
winding
is
tapped
and
wired
to
a
tap
blockT
in
the
front
of
the
relay
.
The
secondary
winding
is
con
nected
to
the
Zener
d
ipper
circuit
and
from
a
fixed
tap
to
the
relay
coil
circuits
.
2.3
Polar
Unit
This
unit
consists
of
a
rectangular
-
shape
magnetic
frame
,
an
electromagnet
,
a
permanent
magnet
,
and
an
armature
with
either
one
or
two
contacts
.
Thepoles
of
the
crescent
-
shaped
permanent
magnet
bridge
the
magnetic
frame
.
The
magnetic
frame
consists
of
three
pieces
joined
in
the
rear
with
two
brass
rods
and
sflvei
solder
.
These
non
-
magnetic
joints
represent
air
gaps
which
are
bridged
by
two
adjustable
magnetic
shunts
.
The
operating
and
restraint
windings
are
concentrically
wound
around
a
magnetic
core
.
The
armature
is
fas
-
tened
to
this
coreatoneend
and
floatsfnthefrontair
gap
atthe
otherend
.
The
moving
contact
is
connected
to
the
free
end
of
a
leaf
spring
.
The
HCB
-
1
and
HCB
relays
are
not
compatible
,
since
the
filter
response
is
not
the
same
.
2
.
CONSTRUCTION
The
relay
consists
of
a
combination
positive
,
nega
-
tive
,
and
zero
phase
sequence
filter
,
a
saturating
auxil
-
iary
transformer
,
two
full
wave
rectifier
units
,
a
polar
unit
,
a
Zener
dipper
,
and
an
indicating
contactor
switch
(
ICS
)
,
all
mounted
in
a
single
case
.
The
external
equip
-
ment
normally
supplied
with
the
relay
consists
of
an
insulating
transformer
,
a
millimeter
and
test
switch
.
All
possible
contingencies
which
may
arise
during
installation
,
operation
,
or
maintenance
,
and
all
details
j
and
variations
of
this
equipment
do
not
purport
to
be
covered
by
these
instructions
.
If
further
information
is
desired
by
purchaser
regarding
this
particular
installation
,
operation
or
maintenance
of
this
equipment
,
the
local
Asea
Brown
Boveri
representative
should
be
contacted
.
Courtesy of NationalSwitchgear.com

I
.
L
.
41
-
9713
L
in
Figure
4
.
Since
the
voltages
add
,
most
of
the
current
will
circulate
throughthe
restraint
coils
andthe
pilot
wire
,
with
a
minimum
of
operating
coil
current
.
The
relative
effects
of
the
operating
and
restraint
coil
currents
are
such
that
the
relay
is
restrained
.
2.4
Restraint
Taps
A
set
of
restraint
taps
are
located
on
the
front
of
the
relay
near
the
polar
unit
These
taps
are
the
maximum
and
minimum
restraint
taps
of
the
relay
.
2.5
indicating
Contactor
Switch
Unit
(
ICS
)
During
an
internal
fault
,
the
relative
Vs
voltages
reverse
.
Since
the
VS
voltages
now
oppose
each
other
,
most
of
the
current
flowing
in
the
restraint
coils
is
also
forced
through
the
operating
coils
with
a
minimum
of
current
in
the
pilot
wire
.
This
increase
in
operating
current
overcomes
the
restraining
effect
and
both
the
relays
operate
.
Thedc
indicating
contactor
switch
isasmall
dapper
-
type
device
.
A
magnetic
armature
,
to
which
leaf
-
spring
mounted
contacts
are
attached
,
is
attracted
to
the
magnetic
core
upon
energization
of
the
switch
.
When
the
switch
closes
,
the
moving
contacts
bridge
two
stationary
contacts
,
bypassing
the
main
relay
contacts
.
Also
during
this
operation
,
two
fingers
on
the
armature
deflect
a
spring
located
on
the
front
of
the
switch
,
which
allows
the
operation
indicator
target
to
drop
.
Thetarget
is
reset
from
the
outside
of
the
case
by
a
push
rod
located
at
the
bottom
of
the
cover
.
Within
limits
,
as
defined
in
Figure
7
and
under
“
Characteristics
,
”
all
the
relays
will
operate
for
an
inter
-
nal
fault
regardless
of
the
fault
current
distribution
at
the
various
stations
.
The
nominal
pickup
(
total
internal
fault
current
)
of
the
relaying
system
is
equal
to
the
minimum
trip
of
a
single
relay
multiplied
by
the
number
of
relays
.
For
example
,
if
the
pickup
of
each
relay
,
with
the
pilot
wire
open
,
is
6
amperes
,
a
two
terminal
line
system
has
a
nominal
pickup
of
2
X
6
=
12
amperes
.
The
front
spring
,
in
addition
to
holding
the
target
,
provides
restraint
forthe
armature
,
and
thus
controls
the
pickup
value
of
the
switch
.
3.1
Pilot
Wire
Effects
3
.
OPERATION
In
Figure
4
it
can
be
seen
that
a
short
-
circuited
pilot
wire
will
short
circuit
the
relay
operating
coils
.
Depend
-
ing
on
the
location
of
the
short
,
at
least
one
of
the
relays
will
fail
to
trip
during
an
internal
fault
.
If
the
pilot
wire
is
open
circuited
,
almost
all
the
restraint
coil
current
will
flow
through
the
operating
coil
,
and
the
relay
operates
as
an
overcurrent
relay
on
fault
currents
.
The
connection
of
the
HCB
-
1
system
of
relays
to
the
protected
transmission
line
shown
in
Fig
.
10
.
In
such
a
connection
,
the
relays
operate
for
faults
within
the
line
terminals
but
not
for
faults
external
to
the
protected
transmission
line
.
This
is
accomplished
by
comparing
the
relative
polarities
of
voltages
at
opposite
ends
of
the
transmission
line
by
means
of
a
metallic
pilot
wire
.
Excessive
pilot
wire
series
impedance
will
ap
-
proach
an
open
-
circuited
condition
and
the
relays
will
operate
during
external
faults
.
Excessive
pilot
wire
shunt
capacitance
will
approach
a
short
-
circuited
con
-
dition
and
the
relays
will
not
operate
.
The
pilot
wire
requirements
are
given
in
Table
IV
.
As
shown
in
Figure
4
,
the
composite
sequence
filter
of
each
HCB
-
1
relay
receives
three
phase
current
from
the
current
transformers
of
the
transmission
line
.
The
composite
sequence
filter
of
the
HCB
-
1
converts
the
three
-
phase
current
input
into
a
single
-
phase
voltage
output
,
Vp
,
of
a
magnitude
which
is
a
function
of
the
positive
,
negative
and
zero
sequence
components
of
fault
current
.
This
voltage
,
Vp
,
is
impressed
on
the
primary
wiring
of
the
saturating
transformer
.
The
satu
-
rating
transformer
output
voltage
,
Vs
,
is
applied
to
the
relay
coils
and
to
the
pilot
wire
through
an
insulating
transformer
.
The
saturating
transformer
and
a
zener
clipper
across
its
secondary
winding
serve
to
limit
the
energy
input
to
the
pilot
wire
.
3.2
Polar
Unit
Theory
The
polar
unit
flux
paths
are
shown
in
Figure
5
.
With
balanced
air
gaps
,
the
permanent
magnet
produces
flux
flowing
in
two
path
,
one
through
the
front
gaps
and
one
through
the
rear
gaps
.
This
flux
produces
north
and
south
poles
,
as
shown
.
By
turning
the
left
shunt
in
,
some
of
the
flux
is
forced
through
the
armature
,
making
it
a
north
pole
.
Thus
,
reducing
the
left
hand
rear
gap
will
produce
a
force
tending
to
pull
the armature
to
the
right
.
Similarly
,
reducing
the
right
-
hand
gap
will
produce
a
force
tending
to
pull
the
armature
to
the
left
.
During
an
external
fault
,
assuming
matched
relays
,
the
magnitude
of
Vs
at
both
stations
will
be
the
same
.
The
relative
polarities
of
the
Vs
voltages
will
be
as
shown
2
Courtesy of NationalSwitchgear.com

I
.
L
.
41
-
971.3
L
Fig
1
.
Type
HCB
-
1
Relay
Without
Case
(
Front View
)
3
Courtesy of NationalSwitchgear.com

I
.
L
.
41
-
9713
L
50
Ohm
Resistor
Saturating
T
ransformer
Fixed Resistor
Point
Diode
Bridge
Fig
.
2
.
Type
HCB
-
1
Relay
Without
Case
(
Rear
View
)
4
Courtesy of NationalSwitchgear.com

I
.
L
.
41
-
9713
L
the
relay
will
pick
up
at
approximately
53
%
of
the
tap
setting
.
This
difference
in
pickup
current
for
different
phase
-
to
-
phase
faults
is
fundamental
;
and
occurs
be
-
cause
of
the
angles
at
which the
positive
and
negative
sequence
components
of
current
add
together
.
Electrical
flux
produced
by
current
flowing
in
the
operating
and restraint
windings
of
the
polar
unit either
adds
to
or
subtracts
from
the
magnetic
flux
.
In
the
case
of
restraint
current
,
the
flux
adds
to
the
magnetic
flux
to
keep
the
armature
to
the
right
.
On
the
other
hand
,
the
operating
current
subtracts
from
the
magnetic
flux
to
move
the
armature
to
the
left
.
On
an
ampere
turn
basis
,
the
polar
unit
operates
when the
operating
ampere
turns
are
greater
than
the
restraint
ampere
turns
plus
the
magnetic
restraint
or
bias
expressed
in
ampere
turns
.
In
some
applications
,
the
maximum
load
current
and
minimum
fault
current
are
too
dose
together
to set
the
relay
to
pick
up
under
minimum
fault
current
,
and
not
operate
under
load
with
the
pilot
wire
accidentally
open
.
For these
cases
,
tap
B
is
available
which
cuts
the
three
phase
sensitivity
in
half
,
while
the
phase
-
to
-
phase
set
-
ting
is
substantially unchanged
.
The
relay
then
trips
at
90
%
of
tap
value
for
AB
and
CA
faults
,
and
at
twice
tap
value
for
three
-
phase
faults
.
The
setting
for
BC
faults
is
65
percent
of
tap
value
.
4
.
CHARACTERISTICS
The
voltage
,
VF
,
impressed
by
the
filter
upon
the
saturating
transformer
varies
with
the
tap
setting
(
A
,
B
,
C
)
of
the
relay
.
It
is
possible
to
eliminate
response
to
positive
se
-
quence
current
entirely
,
and
operate
the
relay
on
nega
-
tive
-
plus
-
zero
sequence
current
.
Tap
A
is
available
to
operate
in
this
manner
.
The
relay
picks
up
at
about
tap
value
for
all
phase
-
to
-
phase
faults
,
but is
unaffected
by
balanced load
current
or
three
-
phase
faults
.
V
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Y
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S
^
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V
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INDICATING
CONTACTOR
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JtasjNO
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]
For
ground
faults
,
separate
taps
G
and
H
are
avail
-
able
for
adjustment
of
the
ground
fault
sensitivity
to
about
1
/
4
or
1
/
8
of
the
upper
tap
plate
setting
.
For
example
,
if
the
upper
tap
plate
is
set at
tap
4
,
the
relay
pick
-
up
current
for
ground
faults
can
be either
1
or
1
/
2
ampere
.
It is
possible
to
eliminate
response
to
zerc
sequence
current
.
Tap
F
provides
such
an
operation
.
»
2
'
"
Cui
-
M
*
SATURATING
TRANSFORMER
ZENER
AC
CLINFER
"
"
W
ruse
RESISTORS
«
0
S
WINDING
MUTUAL
REACTOR
FORMED
WIRE
RESISTOR
.
a
CHASSIS
OPCRATCO
SNORTING
SWITCH
HOTE
:
TERMINALS
TO
»
E
JUMREREC
AT
RCLAT CASE
RED
HANDLE
CURRENT
TEST
JACK
The
response
of
the
relay
to
various
types
of faults
are
summarized
in
the
following
tables
.
L
6
frri
TEST SWITCH
TERMINAL
0
FRONT
VIEW
Sub
5
763
A
628
TABLE
I
-
PHASE
FAULTS
Sequence Components
in
Sequence
Filter
Output
Taps Pickup
-
Multiples
ofT
*
Fig
3
.
Internal
Schematic
of
the
Type
HCB
-
1
Relay
in
FT
-
42
Case
(
Double
Trip
Circuit
)
.
For
the
Single
Trip
Relay
,
the
Circuits
Associated
with
Terminal
llare
omitted
BC
AB
3
*
CA
C
Pos
.
,
Neg
.
,
Zero
86
53
1
B
Pos
.
,
Neg
.
,
Zero
9
£
5
2
The
sequence
network
in
the
relay
is
arranged
for
several
possible
combinations
of
sequence compo
-
nents
.
For
tap
C
the
output
of
the
network
will
contain
the
positive
,
negative
and
zero
sequence
components
of
the
line
current
.
In
this
case
,
the
taps
on
the
upper
tap
plate
indicate
the
balanced three
phase
amperes
(
posi
-
tive
sequence
amperes
)
which
will
pick
up
the
relay
with
the
pilot
wire
open
.
Neg
.
,
Zero
A
UOO
1.00
TABLE II
-
GROUND
FAULTS
Ground
Fault
Pickup
Multiples
of
T
Tap
Comb
.
Lower
Left
TapG
TapH
Tap
C
.
25
.
12
1
For
phase
-
to
-
phase
faults
AB
and
CA
,
enough
nega
-
tive
sequence
current
has been
introduced
to
allow
the
relay
to
pick
up
at
86
%
of
the
tap
setting
.
For
BC
faults
,
B
.
20
.
10
2
A
.
20
.
10
3
5
Courtesy of NationalSwitchgear.com

I
.
L
.
41
-
9713
L
The
voltage
,
Vp
,
impressed
by
the
filter
upon
the
saturating
transformer
is
:
For
a
phase
A
to
ground
fault
,
if
IA
1
=
U
2
=
IAO
0
A
2
is the
phase
A
negative
sequence
current
)
:
VF
-
C
1
IA
1
+
^
2
A
2
+
0
)
IQ
0
)
0.2
T
=
-
.
2
IAI
+
.
461
A
2
+
4.9
IAQ
Table
III
shows
the
values
of
the
C
-
constants
in
Eq
.
(
1
)
0.2
T
=
<
A
2
=
*
A
0
A
1
“
5.2
Table
III
-
CONSTANTS
FOR
EQUATION
(
1
)
But
:
is
=
^
A
1
=
IA
2
+
I
AO
=
3
Ia
1
C
1
C
2
Co
Tap
(
0.2
T
) (
3
)
A
0 0.26
B
-
0.08
0.34
(
0.2
TX
3
)
C
-
0.20
0.46
So
:
lg
=
3
IAI
=
=
0.12
T
(
A
-
G
fault
)
(
6
)
F
0
5.2
G
2.5
H
4.9
ForT
=
4
ls
=
0.5
For
tap
settings
of
C
and
H
,
the
voltage
,
Vp
,
im
-
pressed
by
the
filter
upon
the
saturating
transformer
is
:
4.2
Nominal
Pickup
(
All
Relays
)
(
2
)
Vp
=
-
,
2
IA
1
+
.
461
Ag
+
4.91
/
^
Volts
The nominal
pickup
,
I
is
defined
as
nom
>
4.1
Single
Relay
Pickup
(
Pilot
Wire
Open
)
ls
=
Kis
(
7
)
nom
Single
relay
pickup
,
ls
,
isdefined
asthe
phase
current
required
to
operate
one
relay
with the
pilot
wire
side
of
the
insulating
transformer
open
circuited
(
H
1
-
H
4
)
.
The
single relay
pickup
point
in
terms
of
filter
voltage
is
:
where
I
total internal
fault
current
nom
K
number
of
relays
(
2
or
3
)
•
s
=
single
-
relay
pickup
with
pilot
wire
disconnected
(
see
above
)
Vp
=
0.2
T
(
Tap
C
)
Vp
=
0.15
T
(
Tap
A
)
VF
=
0.16
T
(
Tap
B
)
(
3
)
For
example
,
in
the
previous example
or a
phase
-
A
-
ground
fault
,
the
single
-
relay
pickup
was
determined
as
lg
=
0.5
ampere
for
4
CH
taps
with
the
pilot
wire
open
.
For
a
two
-
terminal
line
,
the
nominal
pickup
for
a
phase
-
A
-
to
ground
fault
(
4
CH
taps
)
is
:
where
T
is the
saturating
transformer
tap
value
.
Single
relay
pickup
is
defined
by equating
(
2
)
&
(
3
)
:
(
4
)
a
0.2
T
=
-
0.2
Ia
1
+
.
461
^
+
4.9
lA
0
(
A
to
G
)
=
0.5
=
0.5
X
2
=
1.0
ampere
I
Current
ls
varies
with
the
type
of fault
For
example
,
fora
3
phase
fault
,
ls
=
IA
1
,
since
only
positive
sequence
current
is
present
.
Substituting
ls
=
IA
1
in
Eq
.
(
4
)
and
rearranging
,
the
3
phase
fault
pickup
is
:
nom
4.3
Minimum
Trip
(
All
Relays
)
With
equal inputs
to
all
relays
and
zero
pilot
-
wire
shunt
capacitance
,
the
relays
will
operate
at
their
nomi
-
nal
pickup point
.
The
minimum
trip
points
will
vary
somewhat
from
nominal
value
,
depending
on
the
pilot
-
wire
constants
and the
magnitude
and
phase
angle
of
the various
relay
input
currents
.
For
example
,
Figure
6
shows the
relay
operating
points
for
a
two
-
terminal line
,
assuming
input
current
one
relay
only
.
0.2
T
(
3
phase
fault
)
•
s
=
U
1
+
=
T
(
5
)
.
2
For
4
tap
:
ls
=
T
=
4
amp
.
(
3
phase
fault
)
6
Courtesy of NationalSwitchgear.com

IX
.
41
-
971.3
L
INSULATING
TRANSFORMER
SATURATING
TRANSFORMER
SATURATING
TRANSFORMER
PILOT
r
<
s
>
N
A
FILTER FILTER
B
c
j
c
WIRE
R
-
RESTRAINT
COIL
OP
-
OPERATING
COIL
Vs
-
SATURATING
TRANSFORMER
VOLTAGE OUTPUT
{
RELATIVE
POLARITIES
ARE
FOR
THRU
CURRENT
OR
EXTERNAL
FAULT
)
Sub
5
183
A
061
Fig
.
4
.
Simplified
External
Schematic
of
the
HCB
-
1
Relay
System
SHUNT
X
-
u
i
?
PERMANENT
MAGNET
7
N
JL
i
HKT
"
)
—
•
J
T
ARMATURE
ADDITIONAL
FLUX
PATH
N
4
iiPI
'
•
S
N
i
(
j
^
N
i
G
MOVING
CONTACT
I
t
BALANCED
AIR
GAPS
UNBALANCED
AIR
GAPS
1
Sub
5
183
A
062
i
1
Fig
.
5
.
Polar
Unit
Permanent
Magnet
Flux
Paths
An
example
of
the
characteristics
with
various
cur
-
rent
distributions
shown
in
Figure
6
.
The
filter
output
voltage
,
VF
,
of
each
relay
,
as
defined
by
equation
(
1
)
must
be
in
phase
or
180
degrees
out
of
phase
,
in
order
for
Figure
7
to
apply
.
4.4
Insulating
Transformer
TABLE
IV
Insulating
Transformer
Rat
»
6
/
1
No
.
of
Relays
4
/
1
I
cs
cs
RL
Unless
otherwise noted
,
all
characteristics
pre
-
sented
includean
insulating
transformerwith
each
relay
.
Two
ratios
are
available
:
4
/
1
and
6
/
1
.
The
high
voltage
side
(
H
1
-
H
4
Terminals
)
is connected
to
the
pilot
-
wires
.
1.5
2
2000
:
0.75
'
1000
/
LEG
500
/
LEG
1.8
3
series
loop
resistance
in
ohms
,
total shunt
capacitance
in
microfarads
(
total wire
to
wire
capacitance
)
Where
the shunt
capacitance
excess
the
abovr
;
amount
,
it
may
be
feasible
in
some
cases
to
provide
shunt
reactors
to
compensate
for
the
excessive
capac
-
RL
Cs
4.5
Pilot
-
Wire
Requirements
The
relays
should
not
be
applied
with
pilot
-
wire
series
resistance
or
shunt
capacitance
exceeding
the
following
values
:
7
Courtesy of NationalSwitchgear.com

LL
.
41
-
9713
L
tance
.
The
amount
of
capacitance
which
can
be
com
-
pensated
is
limited
and
varies
depending
upon
the
magnitude
of
the
pilot
-
wire distributed
effect
.
A
shielded
,
twisted
pilot
wire
pair
,
preferably
of
#
19
AWG
or
larger
,
is
recommended
;
however
,
open
wires
may
be used
if
they
are
frequently
transposed
in
areas
of
exposure
to
power
circuit induction
.
The
voltage
impressed
across
either
insulating
transformer
(
HrH
4
Terminals
)
as a
result
of
induction
or
a
rise
in
station
ground
potential
,
should be
less
than
7.5
volts
to
prevent
undesired
relay
operation
.
For
three
-
terminal
applications
,
the
loop
resistance
of
all
legs
of
the
pilot
wire
must
be
balanced
within
5
percent
,
with
variable
resistors
.
The
pilot
wire
resistance
to
be
balanced
is
divided
by
16
and
36
for
the
4
to
1
and
6
to
1
ratio
insulating
transformers
respectively
,
since
the
balancing
resistors
are
located
on
the
relay
side
of
the
insulating
transformers
.
Induced
voltages
and
rises
in
station
-
ground
poten
-
tial
may
be handled
by
the
following
means
:
a
)
Neutralizing
reactors
may
be
connected
in
series
with
the
pilot
to
hold
pilot
wire
potential
close
to
the
remote
ground
potential
in
the
presence
of
a
rise
in
station
-
ground
potential
.
They
do
not
limit
pilot
-
wire
voltages
to
safe
values
in
the
presence
of
a
longitudinal
induced
voltage
.
When
usingthe
neutralizing
reactor
,
the
pilot
-
wire sheath
should
be
insulated
from
station
ground
to
minimize
sheath
-
to
-
pair
potential
.
All
other
parts
in
the
cable
which
are
connected
to
station
ground
should also
be
protected
with
neutralizing
reac
-
tors to
minimize
pair
-
to
-
pair
voltages
.
b
)
Drainage
reactors
may
be connected
across
the
pilot
wire
to
ground through
a
KX
642
protector
tube
.
The
drainage
reactor
is
particularly
effec
-
tive
in
limiting
pair
-
to
-
ground voltage
in
the
pres
-
ence
of
an
induced
voltage
.
When the tube
flashes
,
both wires
are
connected
to
ground
through
the
drainage
reactor
windings
which
offer
a
low
impedance
to
ground
but
maintain
a
high
impedance
to
an
ac
voltage
across
the
wires
.
Thus
,
the
HCB
-
1
system
will
operate
normally
even
though
the
protector
tube has
flashed
over
.
The
drainage
reactor
is
not
in
-
tended
to
handle
a
rise
in
ground
potential
.
c
)
The
neutralizing
and
drainage
reactors
may
be
utilized
together
.
If
the
neutralizing
reactor
is
to
be
of
any
value
,
the
drainage
reactorthrough
the
protector
tube
must
be
connected
to remote
ground
.
111
l
-
UECq
:
HCB
MINIMUM
TRIP
CHARACTERISTIC
C
160
_
140
m
120
100
m
NEAR
RELAY
TRIPS
:
::
FAR
RELAY
TRIPS
80
60
40
20
500 1000
1500
2000
2500
Sub
1
619594
R
-
PILOT
WIRE
RESISTANCE
IN
OHMS
MICROFARADS
DISTRIBUTED CAPACITY
.
.
001
R
Fig
.
6
.
Typical
Curves
Showing
the
Effect
of
the
Pilot
Wire
on
Minimum
Trip
Current
,
Two
-
Terminal
Line
(
Maximum Restraint
Tap
)
.
In
-
sulating
Transformer
4
/
1
ratio
.
For
information
with
reference
to
the insulation and
protection
equipment
,
refer
to
I
.
L
41
-
971.4
.
4.6
Trip
Circuit
The
main
contacts
will
safely
close
30
amperesat
250
volts
d
.
c
.
,
and the seal
-
in
contacts
of
the
indicating
contactor
switch
will
safely
carry
this
current
long
enough
to
trip
a
circuit
breaker
.
The
indicating
contactor
switch has
two
taps
that
provide
a
pick
-
up
setting
of
0.2
or
2
amperes
.
To
change
taps
requires
connecting
the lead
located
in
front
of
the
tap
block
to
the desired
setting
by
means
of
a
screw
connection
.
5
.
SETTINGS
There
are
four
settings
in
the
relay
.
The
correct
tap
setting
should
be determined
as
outlined
under
‘
Setting
Calculations
”
1
)
Restraint
taps
-
maximum
or
minimum
To
change
taps
,
connect
the
lead
in
front of
the
relay
to
the
correct
tap
.
2
)
T
tap
-
4
,
5
,
6
,
7
,
8
,
10
,
and
12
3
)
RT
tap
-
A
,
B
,
C
4
)
R
0
tap
-
F
,
G
and
H
8
Courtesy of NationalSwitchgear.com

IX
.
41
-
9713
L
TYPE
HCB
RELAY
TYPICAL
OPERATING
CHARACTERISTICS
-
MAXIMUM
RESTRAINT
.
WITH
INSULATING
TRANSFORMERS
AND
2000
OHM
PILOT
WIRES
.
VF
OF
NEAR
&
FAR
RELAYS
IN
PHASE
OR
130
°
OUT
OF
PHASE
IF
3000
tV
-
•
ISJ
•
l
\
-
'
\
Z
\
\
.
i
!
t
-
V
.
i
.
\
i
1
.
V
:
i
-
X
I
:
~
1
t
-
X
I
i
>
\
i
i
\
i
;
\
TT
vT
I
;
t
»
\
V
'
•
V
I
I
f
X
;
M
•
•
Vi
~
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)
•
•
\
J
’
•
»
Xi
»
i
M
itS
2500
i
i
i
•
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•
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iV
i
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:
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:
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•
us
<
I
&
2000
“
c
:
z
V
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v
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;
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*
7
NO
TRIP
AREA
!
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=
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•
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VJ
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~
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V
X
I
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zu
.
1500
V
:
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/
V
:
IV
V
n
\
x
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»
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i
j
-
—
®
i
;
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r
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•
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1
-
CURRENT
-
IN
NEAR
RELAY
(
N
)
—
r
I
•
:
I
I
;
i
i
i
1000
2000
3
C
00
f
+
CUSXEMT
IN
XEAR
RELAY
(
h
)
—
—
PSRCENT
OF
NOMINAL
PICXUP
“
X
M
-
COO
7
i
-
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:
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-
LX
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!
t
I
<
t
WITH
HATCHED
TRANSruRHERS
NORMAL
LOAD
AND
THRU
FAULT
;
7
—
.
!
CURRENT
FALL
ALONG
THIS
UNE
^
V
^
T
"
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K
)
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1
V
^
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»
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ill
:
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THESE
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Sitb
1
619591
Fig
.
7
.
Typical
Operating
Characteristics
of
the
HCB
-
1
Relay
System
-
Maximum
Restraint
Tap
,
with
4
/
1
Insulating
Transformers
and
2000
-
Ohm
Pilot
Wire
.
VF
of
Near
and
Far
Relays
in
Phase
or
180
°
Out
of
Phase
5.2
Setting
Calculations
5.1
Indicating
Contactor
Switch
(
ICS
)
TheHCB
-
1
relay
has
four
sets
of
taps
:
R
^
T
,
Ro
.
and
restraint
taps
.
The
following
discussion
establishes
limits
forthe
various
tap
settings
under
different
operat
-
ing
conditions
.
It
should
be
kept
in
mind
that
settings
to
obtain
operation
on
minimum
internal
fault
conditions
are
based
on
the
total
fault
current
that
flows
into
the
protected
line
from
all
terminals
.
The
only
setting
required
on
the
ICS
is
the
selection
of
the
0.2
or
2.0
ampere
tap
setting
.
This
selection
is
made
by
connecting
the
lead
located
in
front
of
the
tap
block
to
the
desired
setting
by
means
of
the
connecting
screw
.
9
Courtesy of NationalSwitchgear.com

I
.
L
.
41
-
971.3
L
TERMS
The
taps
must
be
set
the
same
at
all
stations
.
Where
the
CT
ratiosare
not
identical
use
auxiliary
CT
’
sto
match
the
currents
within
5
%
of
each other
.
A
,
B
,
C
,
D
,
F
,
G
,
H
-
Relay
taps
total
minimum internal
3
-
phase
secondary
fault
current
fed
from
all
terminals
,
divided
by
the
number
of
terminals
(
2
or
3
)
UP
5.2
.
2
Ground
Fault
Sensitivity (
Rg
TAP
)
The
ground
fault
pickup
is determined
by
G
,
H
and
T
taps
.
(
T
should
be
determined
by
the
phase
setting
.
)
The
minimum
fault
current
lg
should exceed
the
follow
-
ing
:
maximum
secondary
load
current
flowing
through
the
protected
line
.
IL
Tap
A
or
B
:
lg
=
.
20
T
(
Tap
G
)
;
lg
=
.
10
T
(
Tap
H
)
Tap
C
:
lg
=
.
25
T
(
Tap
G
)
;
lg
=
.
12
T
(
Tap
H
)
total
minimum
secondary
ground
fault
current
fed
into
the
protected
line
from
all
ter
-
minals
,
divided
by
the number
of
terminals
.
’
g
For cable
circuits
,
where
the line
charging
current
exceeds
5
%
of
nominal
positive
sequence
pickup
cur
-
rent
,
set
tap
G
;
otherwise
set
tap
H
.
The
taps
must
be
set
identically
at
all stations
.
Use
auxiliary
CT
’
s
where the
main
CT
’
s
have
a
different
ratio
.
The
currents
should
match
within
5
%
.
Inom
.
(
P
-
P
)
nominal
internal
phase
to
phase
fault
sensitivity
.
5.2
.
3
Restraint
Tap
(
Max
.
and
Min
.
Taps
)
Inom
(
P
-
G
)
nominal internal line
to
ground
fault
sensitivity
.
Set
in
maximum
restraint
tap
for
all
two
-
terminal
lines
.
Set
in
minimum
restraint
tap
for
all
three
terminal
lines
.
The
use
of
maximum restraint
on
two
terminal
applications
allows
the
relay
to
be
used
for
all
pilot
wires
as
indicated
in
Table
IV
.
The
use
of
minimum
restraint
on
three
terminal
applications
compensates
for
the
desensitizing
effect
of
a
third
terminal
.
RNC
(
I
)
,
R
NC
(
II
)
current
transformer
ratio
at
Station
I
and
II
respectively
5.2
.
1
Phase Fault
Sensitivity
(
R
1
AND
Taps
)
The
phase
fault
pickup
is determined
by
the
B
,
C
and
T
taps
.
I
n
order
to
operate
on
the
minimum
3
phase
fault
current
,
the
T
tap
should be
set
for
not
more
than
:
Note
:
The
relay
pick
-
up
calibration
will
change
slightly
(
within
5
%
)
between minimum
restraint
tap
and
maximum
restraint
.
In
most
application
,
it
is
not
necessary
to
recalibrate
the
relay
when
changing
to
the
minimum
re
-
straint
tap
.
(
8
)
T
=
l
3
p
(
tap
C
)
;
T
=
0.5
lap
(
tap
B
)
In
order
to
prevent
operation
on
load
current
if
the
pilot
wires
become
open
circuited
,
the
T
tap
should
be
set
for
not
less
than
:
5.2
.
4
Tapped
Loads
Where
one
transformer
bank is
tapped
to
a
line
protected
with
two
HCB
-
1
relays
,
the
critical
point
is
to
set
above
the
fault
current
flow
for
a
fault
on
the
other
side
of
the
bank
.
Set
the
T
for
not
less
than
:
(
tap
B
)
(
9
)
T
=
lL
(
tap
C
)
;
T
=
II
2
The
available
taps
are
:
T
=
1.91
!
PL
(
tapC
)
;
T
=
1.52
IPL
(
tapB
)
(
12
)
T
:
4
,
5
,
6
,
7
,
8
,
10
,
12
where
lPL
=
total
secondary
fault
current
feed
from
all
terminals
to
a
phase
-
to
-
phase
fault
on
the
low
side
of
the
bank
,
divided
by
the
number
of
terminals
(
2
or
3
)
Where
sufficient
fault
current
is
available
,
it
is
recom
-
mended
that
the
relays
be
set
as
follows
:
T
=
1.25
lL
(
tap
C
)
;
T
=
0.62
lL
(
tap
B
)
(
10
)
10
Courtesy of NationalSwitchgear.com