ABB 5VHK 250 - Circuit Breaker Operation and Timing; Contact Adjustment and Wipe Check; Contact Air Gap Check; Contact Sequence Check

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ASfiA
OflOWN
eoveat
Circuit
Breaker
Operation
,
Contact
Adjustment
and
Timing
0
,
Close
the
breaker
,
measure
and
record
the
same
dimen
-
sion
,
Contact
Adjustment
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withdrawn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
.
2
.
Fully
Closed
Breaker
Test
(
See
Fig
.
3
)
.
Charge
the
closing
springs
and
turn
the
motor
switch
(
1
)
off
,
C
(
a
$
e
the
breaker
,
gngege
manual
charge
handle
with
charging
lever
(
3
)
.
During
the
Initial
portion
of
the
upward
stroke
of
the
handle
check
to
see
which
direction
the
closing
spring
guides
move
,
If
(
he
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
.
meehanfsm
can
be
heard
to
-
snap
in
*
,
then
the
breaker
did
not
fully
dose
originally
.
Excess
contact
pressure
or
friction
can
gause
this
condition
and
if
it
cannot
be
relieved
then
the
factory
should
be
consulted
.
3
.
Contact
Wipe
(
contact
pressure
)
Check
(
See
Fig
,
5
)
.
The
contact
air
gap
and
contact
wipe
is
sot
at
the
factory
.
These
parrs
should
not
be
repositioned
in
the
field
unless
a
pg
$
hrod
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
wipa
over
the
life
of
the
breaker
and
a
check
should
be
made
to
insure
that
tha
wipe
is
not
less
than
.
020
'
*
.
The
measure
*
ment
is
made
a
$
follows
for
the
three
poles
:
d
.
The
air
gap
is
the
difference
between
the
two
measure
-
merits
.
The
acceptable
limits
are
.
37
$
-
.
$
00
.
with
the
upper
limit
being
approached
as
contact
wipe
approaches
the
minimum
.
5
.
Contact
Sopuence
Check
(
See
Fig
.
5
)
.
All
three
poles
should
touch
within
Z
millisecond
at
normal
dosrng
speeds
.
An
oscillo
-
scope
,
oscillograph
or
other
timing
method
may
bo
used
to
establish
the
2
millisecond
timing
.
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
ihe
test
equipment
and
proce
-
dure
are
correct
,
Also
consider
,
especially
when
testing
with
electronicequipment
.
-
that
,
002
second
*
vacuum
interrupter
contact
bounce
Is
permissible
during
normal
closing
and
this
bounce
can
influence
the
contact
touch
measurements
.
If
it
is
determined
that
the
contabt
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
wkbfn
2
milliseconds
.
The
air
gap
of
the
pole
to
be
changed
should
be
decreased
if
the
contacts
of
that
|
bole
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
pushrpd
(
2
)
clockwise
,
viewing
from
the
top
of
the
breaker
,
and
increased
by
turning
oonterdockwise
.
To
turn
tha
pushrod
(
2
)
first
remove
retainer
and
pin
(
T
)
,
a
.
Close
the
breaker
and
measure
between
the
spring
base
and
nut
(
point
A
)
,
using
gage
pin
,
1
/
4
turn
of
the
pushrod
(
2
)
will
change
the
air
gap
by
approx
.
.
019
.
After
rotating
the
push
rod
,
caref
ully
reposition
the
push
rod
to
align
the
pin
holes
.
Replace
the
pin
arid
retainer
.
During
the
readjust
-
ment
procedure
note
that
the
contact
wipe
end
air
gap
dimen
-
sions
,
specified
previously
,
musi
be
maintained
.
No
more
them
/
2
turn
total
of
the
pushrod
should
be
required
when
readjustingfor
contact
sequence
.
b
.
The
measurement
with
the
breaker
dosed
should
be
at
least
.
093
for
a
new
breaker
.
c
,
When
contact
wipe
less
than
the
.
020
and
it
has
been
determined
that
the
breaker
closes
fully
and
there
r
$
not
a
mechanical
problem
,
then
the
interrupter
should
be
re
-
placed
due
to
contact
erosion
.
After
completing
the
contact
sequence
procedure
,
recheck
the
contact
wipe
and
air
gaps
.
j
"
*
*
*
•
'
"
Return
the
racking
screw
to
lt
$
original
position
by
turning
li
count
*
rciockwi
&
e
approx
,
two
to
'
three
turns
until
it
stops
.
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
,
otc
,
to
monitor
the
time
from
energizing
to
contacts
touch
or
pan
.
.
f
4
.
Contact
Air
G
»
pOh
«
ck
(
See
Fig
.
5
)
.
The
contact
air
gap
is
$
,
et
at
the
factory
at
the
nominal
dimension
of
.
40
.
This
value
will
normally
increase
as
the
contacts
erode
.
A
chock
o
<
the
contact
air
gap
Checks
(
hat
the
breaker
dcos
open
fully
and
thai
the
gap
is
sufficient
(
o
withstand
the
applied
voltage
.
The
measurement
is
made
follows
for
the
three
pole
$
.
a
.
Open
the
breaker
and
discharge
the
closing
springs
.
b
.
Measure
and
record
the
dimension
between
the
top
sur
»
face
of
the
flex
connector
damp
and
the
lead
mounting
bracket
.
Courtesy of NationalSwitchgear.com