ABB VHK-R User Manual

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6
ik
HU
MIPW
ASEA
BROWN
BOVERI
•
Remember
to
discharge
mid
-
band
ring
on
interrupters
so
equipped
.
d
.
The air
gap
is
the
difference
between
the
two
measure
-
ments
.
The
acceptable
limits
are
.
375
-
.
500
,
with
the
upper
limit
being
approached
as
contact
wipe
approaches
the
minimum
.
Circuit
Breaker
Operation
,
Contact
Adjustment
and
Timing
Contact
Adjustment
5
.
Contact
Sequence
Check
(
See
Fig
.
3
)
.
All
three
poles
should
touch
within
2
millisecond
at
normal
closing
speeds
.
An
oscillo
-
scope
,
oscillograph
or
other
timing
method
may
be
used
to
establish the
2
millisecond
timing
.
1
.
To
check
breaker
operation
,
the
breaker
should be
withdrawn
from
the
switchboard
,
and the
racking
screw
turned
two to
three
turns
clockwise
until
the
racking
unlocking
lever
snaps
into
the
first
position
corresponding
to
the
disconnect
position
.
Before
checking
contact
sequence
,
check
that the
contact
wipe
and air
gaps
are
correct
.
It
is
not
expected
that
the
contact
sequence
should exceed the
2
millisecond
limit
;
therefore
,
before
attempting
to
readjust
,
check
that
the
test
equipment
and
proce
-
dure
are
correct
.
Also
consider
,
especially
when
testing
with
electronic
equ
ipment
,
that
.
002
seconds
vacu urn
interrupter
contact
bounce
is
permissible
during
normal
closing
and this
bounce
can
influence
the
contact
touch
measurements
.
2
.
Fully
Closed
Breaker
Test
(
See
Fig
.
2
)
.
Charge
the
closing
springs
and
turn
the
motor
switch
(
1
)
off
.
Close
the
breaker
.
Engage
manual
charge
handle
with
charging
lever
(
3
)
.
During
the
initial
portion
of
the
downward
stroke
of
the handle
check
to
see
which direction the
closing
spring guides
move
.
If
the
spring
guides
start to
move
out
then
the
breaker did
fully
close
.
If
the
spring
guides
begin
to
move
in
and
with
additional
pumping
moves
in
until the
mechanism
can
be
heard
to
"
snap
in
"
,
then
the
breaker
did
not
fully
close
originally
.
Excess
contact
pressure
or
friction
can
cause
this condition
and
if
it
cannot
be
relieved
then
the
factory
should be
consulted
.
If
it
is
determined that the
contact
sequence
is
not
within
the
2
milliseconds
,
then
adjustment
is
required
.
Usually
,
readjustment
of
one
pole
should be
sufficient
so
that
all
three
poles
touch
within
2
milliseconds
.
The air
gap
of
the
pole
to
be
changed
should be
decreased
if
the
contacts
of
that
pole
are
touching
after
the
other
two
poles
,
or
increased
if
the
contacts
are
touching
before
the
other
two
poles
.
The air
gap
is decreased
by
turning
pushrod
(
2
)
clockwise
,
viewing
from
the
top
of
the
breaker
,
and increased
by
turning
conterclockwise
.
3
.
Contact
Wipe
(
contact
pressure
)
Check
(
See
Fig
.
3
)
.
The
contact
air
gap
and
contact
wipe
is
set at
the
factory
by setting
the
vertical
position
of
the
interrupter
(
1
)
and the vertical
position
of
the
pushrod
(
2
)
.
These
parts
should
not
be
repositioned
in
the
field
unless
a
pushrod
change
is
required
to
correct contact
sequence
as
described
elsewhere
.
Contact
wipe
is
set at
the
factory
at
.
093
minimum
.
Contact
erosion
and
wear
in
mechanical
parts
will
cause a
reduction
in
contact
wipe
over
the
life of
the
breaker and
a
check
should be
made
to
insure that
the
wipe
is
not
less
than
.
020
"
.
The
measurement
is
made
as
follows
forthe
three
poles
:
1
/
4
turn
of
the
pushrod
(
2
)
will
change
the air
gap
by
approx
.
.
019
.
After
rotating
the
pushrod
,
carefully
reposition
the
moving
contact
and
pushrod
vertically
to
align
the
pin
holes
.
Replace
the
pin
and
retainer
.
During
the
readjustment
procedure
note
that the
contact
wipe
and air
gap
dimensions
,
specified
previously
,
must
be
maintained
.
No
more
than
1
/
2
turn
total
of
the
pushrod
should be
required
when
readjusting
for
contact
sequence
.
a
.
Close
the breaker
and
measure
between the
spring
base
and
nut
(
point
A
)
,
using
gage
pin
.
After
completing
the
contact
sequence
procedure
,
recheck
the
contact
wipe
and
air
gaps
.
b
.
The
measurement
with
the
breaker
open
should be
at
least
.
093
for
a
new
breaker
.
Return the
racking
screw
to
its
original
position
by turning
it
counterclockwise
approx
,
two to
three
turns
until
it
stops
.
c
.
When
contact
wipe
is
less
than
the
.
020
and
it
has been
determined that the breaker
closes
fully
and there
is
not
a
mechanical
problem
,
then
the
interrupter
should
be
re
-
placed
due
to
contact
erosion
.
Closing
and
Opening
Times
and
Speeds
After
the
operation
intervals
noted
previously
,
the
closing
and
opening
times
are
recommended
to
be
checked
by
use
of
a
cycle
counter
,
travel recorder
*
,
oscillograph
,
etc
.
to
monitor
the time
from
energizing
to
contacts
touch
or
part
.
4
.
Contact
Air
Gap
Check
(
See
Fig
.
3
)
.
The
contact
air
gap
is
set
at
the
factory
at
the
nominal
dimension
of
.
40
.
This
value
will
normally
increase
as
the
contacts
erode
.
A
check
of
the
contact
air
gap
checks that
the
breaker
does
open
fully
and
that
the
gap
is
sufficient
to
withstand the
applied
voltage
.
The
measurement
is
made
as
follows
for
the three
poles
.
*
A
potentiometer
with
mounting
support
,
used
in
conjunction
with
an
oscilloscope
or
oscillograph
,
and
instructions
are
available
on
special
orderfor
specifically
checking opening
and
closing
speeds
.
a
.
Open
the
breaker
and
discharge
the
closing
springs
.
b
.
Measure and
record the
dimension
between
the
top
sur
-
face
of
the
flex
connector
clamp
and
the lead
mounting
bracket
.
c
.
Close
the
breaker
,
measure
and
record the
same
dimen
-
sion
.
Courtesy of NationalSwitchgear.com

ABB VHK-R Specifications

General

Brand	ABB
Model	VHK-R
Category	Circuit breakers
Language	English