ABB ITH Manual
Instruction
Leaflet
I
.
L
.
41
-
771
G
A
»
1
»
ABB
Power
T
&
D
Company
Inc
.
Relay
Division
Coral
Springs
,
FL
33065
Type
ITH
Relay
Effective
October
1977
Supersedes
I
.
L
41
-
771
F
dated
May
1975
Denotes
change
since
previous
issue
CAUTION
Before
putting
relays
into
service
,
remove
all
blocking
which
may
have
been
inserted
for
the
purpose
of
securing
the
parts
during
shipment
,
make
sure
that
all
moving
parts
operate
freely
,
inspect
the
contacts
to
see
that
they
are
clean
and
close
proper
-
ly
,
and
operate
the
relay
to
check
the
settings
and
electrical
connections
.
The
High
Drop
-
Out
Instantaneous
Trip
Unit
(
ITH
)
The
high
drop
-
out
instantaneous
trip
unit
is
a
small
solenoid
type
device
(
Fig
.
1
)
.
A
plunger
as
-
sembly
(
Fig
.
2
)
rides
up
and
down
on
a
vertical
guide
rod
in
the
center
of
the
solenoid
coil
.
The
plunger
assembly
consists
of
a
bushing
which
is
threaded
on
the
moving
plunger
and
locked
in
place
byanut
,
anda
silver
disc
which
rests
on
a
helical
compression
spring
at
the
lower
end
of
the
plunger
.
The
guide
rod
is
fastened
to
the
stationary
core
which
in
turn
is
held
in
place
by
the
insulating
plate
on
which
the
stationary
contacts
are
mounted
.
The
stationary
core
consists
of
two
steel
sections
separated
by
a
non
-
magnetic
ring
.
This
non
-
magnetic
ring
provides
an
air
gap
in
which
the
plunger
steel
floats
.
When
the
coil
is
energized
,
the
plunger
assembly
moves
upward
Q
carrying
the
silver
disc
which
bridges
three
spring
type
conical
-
shaped
stationary
contacts
.
In
this
posi
-
tion
the
helical
spring
is
compressed
and
the
plunger
is
free
to
move
while
the
contact
disc
remains
sta
-
tionary
.
Thus
,
ac
vibrations
of
the
plunger
assembly
are
prevented
from
causing
contact
chattering
.
A
Micarta
disc
which
acts
as
a
shield
for
the
contact
plate
,
screws
on
the
bottom
of
the
guide
rod
and
is
locked
in
position
by
a
small
nut
.
The
adjustable
core
screw
in
the
top
of
the
frame
provides
the
principal
means
for
adjusting
the
current
operating
values
.
APPLICATION
ITH
relays
may
be
utilized
as
overcurrent
fault
detectors
or
as
instantaneous
overcurrent
trip
units
.
They
are
particularly
suitable
as
fault
detectors
be
-
cause
of
their
90
%
dropout
ratio
and
because
of
their
compact
size
.
It
is
recommended
that
these
units
be
used
in
fault
detector
applications
only
where
the
the
contacts
are
called
upon
to
carry
only
trip
coil
current
rather
than
auxiliary
relay
or
timer
current
.
For
example
,
a
zone
1
relay
may
be
supervised
by
an
ITH
relay
,
but
a
zone
2
relay
driving
a
TD
-
5
should
not
(
unless
the
TD
-
5
is
equipped
with
a
TX
slow
dropout
feature
to
override
contact
bounce
)
.
Their
size
also
makes
them
desirable
for
use
in
sup
-
plementing
existing
time
-
overcurrent
relays
or
to
provide
a
second
set
of
instantaneous
trip
units
.
CONTENT
The
relays
consist
of
one
,
three
or
four
high
drop
-
out
instantaneous
units
with
an
equal
number
of
operation
indicators
and
one
contactor
switch
.
In
the
single
unit
relay
the
d
-
c
indicating
contactor
switch
is
used
in
place
of
an
operation
indicator
and
con
-
tactor
switch
.
Contactor
Switch
The
d
-
c
contactor
switch
in
the
relay
is
a
small
solenoid
type
switch
.
A
cylindrical
plunger
with
a
silver
disc
mounted
on
its
lower
end
moves
in
the
core
of
the
solenoid
.
As
the
plunger
travels
upward
,
the
disc
bridges
three
silver
stationary
contacts
.
The
coil
is
in
series
CONSTRUCTION
The
construction
of
the
individual
units
is
as
follows
:
All
possible
contingencies
which
may
arise
during
installation
,
operation
or
maintenance
,
and
all
details
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
ABB
Power
T
&
D
Company
Inc
.
representative
should
be
contacted
.
Printed
in
U
.
S
.
A
.
Courtesy of NationalSwitchgear.com
I
.
L
•
41
-
771
G
TYPE
ITH
RELAY
INTtMAl
SOtOUtlC
IKTUHMl
SCHEMATIC
xxxx
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TEHIML
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view
183
A
152
183
A
128
Fig
.
4
•
Internal
Schematic
of
the
Three
Unit
Type
ITH
Instantaneous
Overcurrent
Relay
•
with
the
main
contacts
of
the
relay
and
with
the
trip
coil
of
the
breaker
.
When
the
relay
contacts
close
,
the
coil
becomes
energized
and
closes
the
switch
contacts
.
This
shunts
the
main
relay
contacts
,
there
-
by
relieving
them
of
the
duty
of
carrying
tripping
cur
-
rent
.
These
contacts
remain
closed
until
the
trip
circuit
is
opened
by
the
auxiliary
switch
on
the
breaker
.
Fig
,
5
.
Internal
Schematic
of
the
Four
Unit
Type
ITH
Instantaneous
Overcurrent
Relay
•
the
frame
and
drop
-
out
at
90
%
of
the
pick
-
up
current
value
.
The
position
of
the
core
screw
determines
the
pick
-
up
value
for
a
particular
contact
gap
.
The
90
%
drop
-
out
ratio
is
accomplished
through
the
right
com
-
bination
of
plunger
steel
setting
,
electrical
pull
and
spring
strength
.
The
most
important
factor
in
the
adjustment
of
the
unit
is
the
correct
positioning
of
the
plunger
steel
with
respect
to
the
stationary
core
air
gap
.
Operation
Indicator
The
operation
indicator
is
a
small
solenoid
coil
connected
in
the
trip
circuit
.
When
the
coil
is
ener
-
gized
a
spring
-
restrained
armature
releases
the
white
target
which
falls
by
gravity
to
indicate
completion
of
the
trip
circuit
.
The
indicator
may
be
reset
from
outside
of
the
case
.
CHARACTERISTICS
ITH
Unit
The
ranges
available
for
the
instantaneous
units
are
0.25
-
0.5
.
0.5
-
1.0
,
1
-
2
,
2
-
4
,
4
-
8
,
6
-
12
,
8
-
16
,
and
16
-
32
amperes
.
The
unit
has
a
nominal
2
to
1
range
of
pick
-
up
adjustment
with
a
90
%
or
greater
drop
-
out
ratio
.
The
core
screw
at
the
top
of
the
unit
is
used
to
change
the
setting
.
The
maximum
core
screw
setting
is
ten
turns
out
from
the
fully
bottomed
position
.
At
the
maximum
end
of
the
range
it
may
be
necessary
to
increase
the
contact
gap
to
obtain
the
desired
pickup
.
As
long
as
the
setting
of
the
unit
is
within
its
nomi
-
nal
rating
the
drop
-
out
ratio
will
be
90
%
or
greater
.
Indicating
Contactor
Switch
Unit
(
ICS
)
The
d
-
c
indicating
contactor
switch
(
Fig
.
3
)
is
a
small
clapper
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
con
-
tacts
bridge
two
stationary
contacts
,
completing
the
trip
circuit
.
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
.
The
nominal
range
may
be
extended
by
increas
-
ing
the
contact
gap
with
the
core
screw
at
its
maxi
-
mum
position
.
The
drop
-
out
ratio
for
settings
above
the
nominal
range
will
be
below
90
%
.
For
example
,
for
a
pick
-
up
setting
of
three
times
the
minimum
set
-
ting
.
the
drop
-
out
ratio
will
be
approximately
60
%
.
Likewise
,
for
a
setting
of
four
times
the
minimum
set
-
ting
,
the
drop
-
out
ratio
will
be
approximately
45
%
.
The
front
spring
,
in
addition
to
holding
the
target
,
provides
restraint
for
the
armature
and
thus
controls
the
pickup
value
of
the
switch
.
OPERATION
The
ITH
unit
is
a
current
operated
device
which
will
pick
-
up
within
the
range
stamped
on
the
side
of
3
Courtesy of NationalSwitchgear.com
TYPE
JTH
RELAY
Resistance
of
0
,
2
ampere
ICS
tap
Resistance
of
2.0
ampere
ICS
tap
6.5
ohms
Mtnui
KKMTIC
0.15
ohms
imieiTiM
CMTACTM
aviTca
oINSTALLATION
The
relay
should
be
mounted
on
switchboard
panels
or
their
equivalent
in
a
location
free
from
dirt
,
moisture
,
excessive
vibration
and
heat
.
Mount
the
relay
vertically
by
means
of
the
rear
mounting
stud
or
studs
for
the
type
FT
projection
case
or
by
means
of
the
four
mounting
holews
on
the
flange
for
the
semi
-
flush
type
FT
case
.
Either
the
stud
or
the
mounting
screws
may
be
utilized
for
grounding
the
relay
.
External
toothed
washers
are
provided
for
use
in
the
locations
shown
on
the
outline
and
drilling
plan
to
facilitate
making
a
good
electrical
connec
-
tion
between
the
relay
case
,
its
mounting
screws
or
studs
,
and
the
relay
panel
.
Ground
Wires
are
affixed
to
the
mounting
screws
or
studs
as
required
for
poorly
grounded
or
insulating
panels
.
Other
electrical
connections
may
be
made
directly
to
the
terminals
by
means
of
screws
for
steel
panel
mounting
or
to
the
terminal
stud
furnished
with
the
relay
for
thick
panel
mounting
.
The
terminal
stud
may
be
easily
removed
or
inserted
by
locking
two
nuts
on
the
stud
and
then
turning
the
proper
nut
with
a
wrench
.
For
detail
information
on
the
FT
case
refer
to
I
.
L
.
41
-
076
.
IT
*
IT
*
:
:
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ICS
OVfKMMST
IT
*
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183
A
1
&
9
Fig
*
6
*
Internal
Schematic
of
ffce
Single
Unit
Type
ITH
Instantaneous
Overcurrent
Relay
*
The
burden
of
this
unit
at
minimum
pick
-
up
is
0.44
V
.
A
.
at
60
hertz
.
Characteristic
operating
times
for
the
unit
over
its
nominal
range
axe
:
Less
than
1
cycle
at
200
%
of
trip
value
1
/
2
cycle
at
500
%
of
trip
value
1
/
4
cycle
at
1000
%
of
trip
value
Continuous
current
rating
of
the
coil
is
2
times
minimum
pickup
value
.
One
second
rating
is
approximately
30
times
min
-
imum
pick
-
up
.
o
SETTINGS
AND
CALIBRATION
ITH
Unit
The
unit
,
prior
to
shipment
is
adjusted
for
mini
-
mum
pick
-
up
value
,
that
is
,
the
lower
value
marked
on
the
side
of
the
frame
.
The
following
procedure
is
used
when
changing
this
setting
over
the
indicated
range
where
a
90
%
or
higher
drop
-
out
ratio
is
desired
.
Connect
the
coil
of
the
unit
in
series
with
an
ammeter
and
adjustable
load
.
Apply
the
desired
pick
-
up
cur
-
rent
,
then
adjust
the
core
screw
until
the
plunger
just
picks
up
.
Lock
core
screw
securely
in
place
.
If
it
is
desired
to
set
the
unit
for
either
a
differ
-
ent
drop
-
out
ratio
over
the
nominal
range
or
for
pick
-
up
values
above
the
nominal
range
,
then
the
following
procedure
should
be
followed
.
Contactor
Switch
The
contactor
switch
is
a
d
-
c
operated
switch
with
a
pick
-
up
of
2.0
amperes
.
Operotlon
Indicator
The
operation
indicator
is
a
d
-
c
operated
indicator
with
a
pick
-
up
of
95
%
of
its
rated
value
.
The
two
standard
indication
ranges
are
0.2
and
1.0
ampere
.
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
.
With
the
desired
drop
-
out
current
applied
,
adjust
the
core
screw
until
the
plunger
assembly
just
drops
out
.
Then
apply
the
desired
pick
-
up
current
and
adjust
the
Micarta
contact
shield
until
the
plunger
just
picks
up
.
It
is
recommended
that
the
contact
gap
should
not
be
made
less
than
.
013
of
an
inch
.
The
contact
gap
may
be
determined
by
turning
up
the
contact
shield
from
the
setting
position
until
the
contacts
just
close
.
CONTACT
CIRCUIT
CONSTANTS
Resistance
of
2.0
ampere
Contactor
Switch
Resistance
of
1.0
ampere
Target
Resistance
of
0.2
ampere
Target
0.25
ohms
0.16
ohms
2.8
ohms
4
Courtesy of NationalSwitchgear.com
I
.
L
.
41
-
771
G
TYPE
ITH
RELAY
One
turn
of
the
shield
is
equal
to
,
018
of
an
inch
con
-
tact
gap
.
circuit
.
The
contactor
switch
and
indicator
must
operate
with
the
application
of
the
current
and
the
contactor
switch
and
indicator
must
not
stick
in
the
The
factory
adjustment
of
the
position
of
the
plunger
steel
provides
a
drop
-
out
ratio
of
90
%
over
the
nominal
range
.
But
,
in
the
event
a
considerable
amount
of
material
is
removed
from
the
contacts
due
to
repeated
operations
,
burnishing
,
etc
.
,
the
drop
-
out
ratio
may
fall
below
90
%
.
If
this
occurs
,
the
plunger
steel
should
be
screwed
down
to
compensate
for
the
change
in
the
contact
gap
.
However
,
if
the
plunger
steel
is
changed
,
the
relay
must
be
recalibrated
.
The
following
procedure
should
be
used
to
recalibrate
the
relay
.
Set
the
core
screw
at
ten
turns
up
from
its
bottom
position
.
Adjust
the
plunger
steel
position
on
the
plunger
until
the
current
value
at
which
the
plunger
drops
-
out
is
90
%
of
the
maximum
rated
current
.
Then
set
the
contact
gap
at
3
/
4
of
a
turn
down
,
and
adjust
the
core
screw
for
pick
-
up
.
Drop
-
out
value
will
nor
-
mally
be
above
90
%
at
this
setting
.
If
desired
,
the
contact
gap
and
follow
may
be
increased
by
lowering
the
contact
shield
and
readjusting
the
core
screw
for
pick
-
up
.
operated
position
when
the
current
is
interrupted
.
Indicating
Contactor
Switch
(
ICS
)
No
setting
is
required
on
the
ICS
unit
except
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
.
O
ADJUSTMENT
AND
MAINTENANCE
ITH
Unit
Acceptance
—
The
plunger
assembly
should
pick
-
up
and
seal
-
in
within
±
5
%
and
dropout
at
90
%
or
higher
of
the
minimum
pick
-
up
current
value
stamped
on
the
frame
.
The
unit
should
maintain
at
least
a
90
%
drop
-
out
ratio
over
the
nominal
range
.
The
contact
gap
should
not
be
less
than
.
013
of
an
inch
.
Contact
gap
is
determined
as
described
under
SETTINGS
.
Contactor
Switch
&
Operation
Indicator
Close
the
main
relay
contacts
and
pass
sufficient
d
-
c
current
through
the
trip
circuit
to
close
the
con
-
tacts
of
the
contactor
switch
.
This
value
of
current
should
not
be
greater
than
the
rating
of
the
contactor
switch
being
used
.
The
operation
indicator
target
should
drop
freely
.
For
Relays
with
Series
Trip
This
combination
uses
a
2.0
amp
.
contactor
switch
and
either
a
1.0
amp
.
or
a
0.2
amp
^
-
operation
indicator
connected
in
series
.
Adjust
the
contactor
switch
and
operation
indicator
as
outlined
below
.
Contoctor
Switch
Indicating
Contactor
Switch
(
ICS
)
Turn
the
relay
up
-
side
-
down
.
Screw
up
the
core
screw
until
the
contact
ring
starts
rotating
.
Now
back
off
the
core
until
the
contact
ring
stops
rotating
.
Back
off
the
core
screw
one
more
turn
and
lock
in
place
.
Adjust
the
two
nuts
at
the
bottom
of
the
switch
so
that
there
is
3
/
32
inch
clearance
between
the
moving
contact
ring
and
the
stationary
contacts
in
the
open
position
.
The
guide
rod
may
be
used
as
a
scale
as
it
has
52
threads
per
inch
,
therefore
,
5
turns
of
the
nut
will
equal
approximately
3
/
32
inch
.
Operotion
Indicotor
Close
the
main
relay
contacts
and
pass
95
%
of
rated
indicator
current
d
-
c
through
the
trip
circuit
.
Adjust
the
operation
indicator
by
moving
the
flag
holder
such
that
the
indicator
operates
with
the
ap
-
plication
of
the
95
%
current
.
Close
the
main
relay
contacts
and
pass
sufficient
d
-
c
current
through
the
trip
circuit
to
close
the
con
-
tacts
of
the
ICS
.
This
value
of
current
should
not
be
greater
than
the
particular
ICS
tap
setting
being
used
.
The
operation
indicator
target
should
drop
freely
.
All
contacts
should
be
cleaned
periodically
.
A
contact
burnisher
S
#
182
A
836
H
01
is
recommended
for
this
purpose
.
The
use
of
abrasive
material
for
clean
-
ing
contacts
is
not
recommended
,
because
of
the
danger
of
embedding
small
particles
in
the
face
of
the
soft
silver
and
thus
impairing
the
contact
.
Repair
work
can
be
done
most
satisfactorily
at
the
factory
.
However
,
interchangeable
parts
can
be
furnished
to
the
customers
who
are
equipped
for
doing
repair
work
.
When
ordering
parts
,
always
give
the
complete
nameplate
data
.
Combination
Test
Pass
30
times
indicator
rating
through
the
trip
5
Courtesy of NationalSwitchgear.com
TYPE
ITH
RELAY
.
563
*
5.563
«
*
'
141.30
)
(
14.30
)
.
250
DIA
.
4
HOLES
FOR
.
190
-
32
MTS
.
SCREWS
(
6.35
)
K
6.063
-
*
|
l
154.00
)
1.594
(
40.49
)
2.781
(
70.64
)
i
J
3.625
i f
]
5.875
,
(
149.23
)
i
U
824
.
I
5
)
(
92.00
)
6.5
A
(
165.1
)
+
4
-
4
k
t
2.938
(
74.6
)
1
3.250
(
82.55
)
3
1
T
"
.
125
i
-
3.188
(
80.98
)
R
.
I
i
|
2.938
(
74.63
)
r
-
5.875
(
149.23
)
^
6.375
-
^
(
161.93
)
PANEL
LOCATION
SEMI
-
FLUSH
MTG
.
PROJECTION
MTG
.
PANEL
CUTOUT
8
DRILLING
FOR
SEMI
-
FLUSH
MTG
.
PILOT
PLATE
SNAP
I
ON
RELAY
(
TAB
TO
f
WHEN
USED
REAR
)
J
^
2.328
(
59.13
)
^
-
CASE
DIMENSIONS
IN
INCHE
DIMENSIONS
IN
MM
LARGE
INTERNAL
\
\
8
>
EXTERNAL
\
\
TOOTH
WASHER
>
J
t
1.875
(
47.63
)
.
2.688
(
68.28
)
-
u
.
563
j
;
(
14.30
)
DIA
.
2
HOLES
_
5.375
(
136.53
)
1
^
SMALL
EXTERNAL
TOOTHED
WASHERS
.
190
-
32
SCREW
SPACER
OR
SPACERS
FOR
THIN
PANELS
_
.
250
(
6.35
)
f
*
l
.
03
l
-
4
*
1.031
-
(
26.19
)
(
26.19
)
+
.
0
I
6
(
.
397
)
.
250
n
(
6.35
)
“
0
L
03
I
-
4
*
1.031
-
4
(
26
.
(
9
)
(
26.19
)
4
*
1
1
.
375
(
9.53
)
R
V
PANEL
/
.
5
/
16
-
18
SCREW
"
"
eq
.
/
(
FOR
THICK
PANELS
(
150
QI
/
USE
5
/
16
-
18
STUDS
)
1
-
4
—
i
M
£
/
)
1.0
yf
(
25.4
)
3
9
5
\
/
7
INTERNAL
-
EXTERNAL
TOOTHED
WASHERS
|
8
I
3
(
46.05
)
I
I
2.0
i
i
(
50.8
)
.
190
-
32
SCREW
FOR
THICK
PANELS
USE
.
190
-
32
STUDS
i
Wr
2
4
6
8
i
l
V
V
.
1
S
’
r
-
CteOe
—
-
.
516
(
13
-
11
)
*
1.031
—
1.031
-
*
*
1.031
-
*
1
*
1.031
(
26.19
)
26.19
)
(
26.19
)
26.19
)
PANEL
DRILLING
OR
CUTOUT
FOR
PROJECTION
MTG
.
(
FRONT
VIEW
)
.
750
TERMINAL
NUMBER
DIA
.
(
19.05
)
10
HOLES
OR
CUTOUT
.
641
TERMINAL
AND
MOUNTING
DETAILS
DIA
:
(
16.28
)
57
-
D
-
79
C
0
Q
Fig
.
7
.
Outline
and
Dri
tling
Plan
for
the
Type
ITH
Relay
in
the
Type
FTll
Cose
.
Courtesy of NationalSwitchgear.com
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