ABB 15VHK500 - Maintenance & Adjustments

AM
IB
6.2
.
7.7
.
-
1
Page
6
ASEA
BROWN
BOVERI
open
the breaker
as
required
.
Open
sliding
door
(
2
)
in
front
compartment
door
(
1
)
.
En
-
gage
racking
crank
(
4
)
and
push
racking
unlocking
lever
(
3
)
to
left
.
Rotate
racking
crank
(
4
)
counterclockwise
approxi
-
mately
1
/
4
turn
,
then
release
unlocking
lever
.
Continue
cranking
counterclockwise
until
racking
mechanism
auto
-
matically
stops
at
“
TEST
'
position
.
and
it
is
not
expected
that the
interrupters
will
have
to
be
replaced
due
to
excessive erosion
of
contacts
.
There is
,
however
,
a
checkforcontact
wipe
(
contact
pressure
)
which
is
also
a
measure
ol
contact
erosion
.
This check
is
covered
under
‘
Circuit
Breaker
Operation
and
Contacts
”
.
When
contact
wipe
is less
than
the
minimum
specified
and
it
has
been
determined
that
the breaker
closes
fully
and
there
is
not
a
mechanical
problem
,
then
the
interrupter
should be
replaced
due
to
contact
erosion
.
If
,
however
after
the
first
inspection
period
there
is
no
indication
of
any
problems
,
actual
operating
experience
with
specific
circuits
will
indicate
the
future
amount
of
maintenance
needed
for
the
various
circuit
breakers
and
the
procedure
can
be
modified
as
required
.
Ol
course
,
where
unusual
service
conditions
exist
,
as
covered
by
ANSI
Standard
C
37.04
,
it
must
be
presumed
that
these
conditions
were
considered
at
the
time
of
order
;
that
the
equipment
supplied
was
designed
for
the
special
application
;
and
that
an
appropriate supplemental
mainte
-
nance
program
has been
developed
.
These
maintenance
instructions
only
cover
circuit
breakers
used under
the
standard service
conditions
.
At
the selected
maintenance
period
,
the
following
tests
and
adjustments
should be
made
;
NOTE
:
The
following
tabulated
tests
and
adjustments
are
those
that
are
normally
necessary
for
proper
maintenance
and
operation
of
the
15
VHK
circuit breaker
.
The
remaining
portions
of
the
breaker
—
close
coil
assembly
,
shunt
trip
device
,
control
relay
,
auxiliary
switch
and
motor
require
no
maintenance
during
the
standard
life
of
the
circuit
breaker
regardless
of
the
operating duty
.
Repeat
same
operation
for
“
DISCONNECT
'
position
.
The circuit
breaker
can
now
be
positioned
for
withdrawal
.
If
in
the
upper
compartment
the
lift
device
must
first
be
located
in
the
correct
position
.
For
withdrawal
from
the
switchboard
,
again
push
the
racking
unlocking
lever
to
the
left
and
turn
the
racking
crank
counterclockwise
only
until
resistance
to
motion
is
felt
.
(
Approximately
2
-
3
turns
—
DO
NOT
FORCE
.
)
The
closing
springs
,
if
charged
,
will
auto
-
matically
discharge
when
the circuit
breaker
is moved
to
the
withdrawn
position
.
The
circuit
breaker
can
now
be
re
-
moved
from
the
compartment
by
pulling
on
the
handle
located
on
the
front
barrier
.
MAINTENANCE
,
ADJUSTMENTS
AND
TESTS
General
Information
j
The
15
VHK
circuit
breakers
are
designed
for
minimum
maintenance
and tested
to
insure
that
minimum
mainte
-
nance
will
be
required
.
The
few
adjustments
that
are
noted
are
required
only
when
an
operational
check
indicates
a
problem
.
Of
course
,
during
the
maintenance
checks
,
all
accessible
bolts
,
nuts
and
screws
should
be
routinely
checked
to
insure that
they
are
tight
,
it
is
recommended
that
the circuit
breaker
be
normally
inspected
after
the
first
2000
operations
,
regardless
of
the
type
of
duty
it
is used
for
.
These
operations
can
be
either
no
-
load
mechanical
,
load
current
switching
,
bulk
capacitor
or
reactor
switching
operations
,
or
for
motor
starting
appli
-
cations
.
Vacuum
interrupters
,
as
used
on
the
15
VHK
circuit break
-
ers
,
have
an
inherently
long
contact
life
and
will
provide
troublefree
service
under varied
application
conditions
,
as
long
as
the circuit
breaker is
applied
within
its
rating
.
The
wear
condition
of
the individual
vacuum
interrupters
will
vary
,
depending
on
circu
it
conditions
and
such
variables
as
single
phase
versus
three
-
phase interruption
,
X
/
R
ratio
(
asymmetry
)
and
relay
delay
times
.
Of
course
,
interrupting
high
short
-
circuit
current
will
cause
contact
erosion
to
occur
faster
than load
current
interruptions
.
The
interrupters
for
the
15
VHK
Circuit
Breakers
are
designed
and
tested
for
2000
%
KSI
minimum
.
It
is
unlikely
that
a
circuit
breaker
will
be
subjected
to
this
much
duty
during
the
life
of
the
breaker
D
.
C
.
Millivolt
Drop
Test
During
maintenance
periods
,
the condition
of
the breaker
current
circuit
can
easily
be
determined
by
performing
a
millivolt
drop
test
.
This
test
should
be
performed
regardless
of
whether
the
circuit breaker
had
interrupted
low
or
high
currents
or
has
minimum
operations
.
The
following
table lists
the
millivolt
drop
and resistance
values
tor
the
circuit
breakers
covered
by
this
instruction
book
,
from
terminal
to
terminal
,
exclusive
of
the
primary
disconnects
.
Maximum
Maximum
MV
Drop
*
Micro
-
Ohms
Curcuit
Breaker
15
VHK
500
/
750
1
200
Ampere
7
35
;
15
VHK
500
/
750
2000
Ampere
6
30
‘
Millivolt
drop
with
200
amperes
DC
flowing
.
Courtesy of NationalSwitchgear.com