Westinghouse De-opn User manual

i
-
S
Electric
Corporation
*
:
•
*
ouse
r
;
i
:
r
-
vt
l
Courtesy of NationalSwitchgear.com

*
:
•
s
-
viy
.
:
?
i
-
"
'
iiV
'
.
¥
Y
;
_
"
-
V
.
!
,
-
.
•
•
r
.
,
.
7
-
7117
'
v
..
/
v
/
/
/
/
V
•
ivv
.
:
7
.•
.
Y
•
-
.•
•
''
-
.
7
J
•
-
•
:
"
•
'
/
:
S
1
-
7
-
'
-
ViV
/
V
-
i
yyyyjffi
;
/
i
-
v
’
-
'
-
r
*
•
•
•
,
.
•
•
•
•
•
.
'
i
i
V
-
•
.
.
!
»
-
L
-
•
••
.•
.
>
•
VS
.
-
/
'
-
:
o
-
v
•
;
;
.
V
if
.
S
*
-
:
i
-
.
/
yyyV
,
:
~
\
*
•
:
:
r
.
•
*
-
•
.
*
?
•
:
'
/
•
-
,
V
'
,
1
*
'
;
V
,
'
.
"
t
•
r
r
-
r
•
'
•
.
.
-
f
-
.
!
v
,
>
v
-
•
r
.
/
•
V
t
•
*
:
v
-
:
-
&
1
V
^
*
v
>
-
:
v
:
;
Y
-
:
..
.
i
.
.
?
'
.
-
'
.
-
-
y
.
/
•
••
L
-
*
:
/
•
I
Y
!
.
;
'
v
J
?
:
,
i
.
.
.
>
:
.
V
1
-
/
.
sPECiAi
monnoES
s
v
:
>
•
'
5
T
-
:
*
.
•
•
•
I
?
.
/
vv
'
:
-
.
-
:
/
•
.
r
.
-
ito
&
K
:
v
“
-
•.
V
•
•
*
.
V
.
"
-
:
/
-
•
>
.
-
T
‘
•
-
‘
r
,
.
.
.
.
...
.
.
VS
•
•
«
.
I
f
*
V
;
v
;
/
*
fv
=
•
-
•
-
•
•
•
'
V
.
,
;
:
v
;
-
.
:
s
*
:
-
?
v
!
'
•
.
:
»
n
:
-
r
-
t
N
-
r
•
-
-
v
.
V
;
,
V
-
/
'
•
vV
;
'
-
’
/
.
*
'
K
$
%
7
-
^
M
>
j
J
\
,
•
.
••
.
.
yT
.
:
'
'
I
-
’’
’
"
l
’
-
*
n
,
•
.
:
‘
•
j
’
*
’
*
!
.
.
-
*
\
.
•
.
’
’
•
.
*
'
/
*
\
*
‘
'
When
communicating
with
Westinghouse
regarding
the
product
covered
by
this
Instruction
Book
,
include
all
data
cbiitained
;
6
n
the
nameplate
attached
to
the
•
equipment
^
.
.
~
-
..
.
.
^
*
.
'
.
.
*
•
‘
.
.
"
.
11
.
*
“
*
*
-
.
.
'
.
.
V
*
"
.
—
.
^
'
,
.
.
.
-
.
..
~
Y
'
\
..
.
*
,
.
!
.
..
.
.
i
,
*
.
..
,
'
•
_
.
.
.
»
.
'
.
.
Also
^
to
facilitate
replied
when
pai
^
qular
informatibii
i
$
d
«
B
-
\
/
gired
^
be
suite
state
^
fully
1
and
^
clearly
the
!
probleto
and
^
y
,
attendant
conditidns
^
T
\
:
Wl
•
•
=
.
;
v
?
n
.
-
'
/
••
,
"
.
*
vv
•
"
-
•
»
;
,
y
,
r
:
Ks
:
:
-
:
:
’
.
••
"
.
.
’
•
•
.
.
.
£
?
»
•
;
5
..
-
v
/
•
/
-
;
•
U
-
:
;
’
s
-
r
r
.
t
.
•
*
.
!
A
%
«
•
*
•
*
.
v
•
•
•
•
-
K
\
\
'
7
.
•
•
•
*
•
r
.
•
'
•
•
:
;
-
>
iV
/
:
-
5
»
.
V
.
.
•
•
•
I
-
»
.
c
:
:
Vi
:
>
.
?
•
:
V
:
.
V
"
•
.
V
;
i
;
.
,
-
r
•
:
•
’
y
.
V
'
V
.
-
v
r
:
-
m
-
=
itt
-
•
•
•
-
V
%
"
-
vr
.
-
V
-
V
’
V
'
-
VvvV
•
•
'
i
>
V
;
v
-
pry
;
V
r
.
-
i
.
’
?
v
-
v
.
r
.
:
-
VVV
/
/
/
:
•
V
?
-
r
f
:
.
-
-
N
.
r
V
»
Addre
^
to
the
nearest
Westingheusb
c
4
;
vvv
:
;
;
V
i
:
»
-
.
V
.
v
'
vi
'
-
.
;
Ilf
i
Vv
-
>
;
i
•
•
»
•
'
-
Vi
-
7
-
/
;
/
.
:
v
-
Av
'
i
-
-
J
.
>
*
representative
as
listed
in
the
back
of
this
book
p
-
'
.
-
y
:
/
-
-
s
-
'
-
y
;
v
,
-
/
,
rV
.
'
/
‘
/
.
/
i
”
i
=
.
V
-
J
%
'
’
*
O
-
f
I
-
•
»
•
•
•
.
-
.
.
-
:
•
•
'
•
•
-
.
’
VV
'
/
rylr
-
y
-
V
.
'
-
J
T
.
•
f
.
-
.
•
•
•
\
Kv
-
i
-
i
,
;
•
>
•
vf
i
'
:
-
6
-
:
y
'
f
'
>
v
:
V
:
?
.
-
•
V
-
i
"
•
:
.
.
Vif
;
i
'
WV
/
V
'
V
.
:
V
,
=
:
•
•
:
>
•
;
V
T
.
3
V
--
VJ
:
j
.
.
.
H
•
I
'
.
;
cvy
.
<
’
•••
A
.
-
*
1
y
.
l
;
*
-
i
s
J
*
;
y
!
>
J
i
-
>
•
-
Vi
.
,
,
;
,
,
.
;
,
'
»
•
Y
'
•
•
/
/
r
..
.
.
.
..
v
%
.
*
•
-
-
1
•
X
‘
I
“
i
.
•
.
•
•
:
,
V
'
:
4
.
VV
.
v
.
1
-
•
:
.
V
-
j
:
r
.
-
;
•
i
,
...
,
4
•
V
^
V
.
<
-
?
'
v
1
•
v
;;
•
V
.
-
:
.
•
;
.
v
.
l
.
'
f
'
-
v
VV
.
Vyi
I
—
.
C
'
V
-
/
"
:
-
:
.
y
4
v
.
:
:
/
y
,
-
i
-
£
•
’
>
:
^
V
fi
.
j
i
V
r
*
-
L
:
'
:
V
;
k
v
_
/
•
:
•
:
-
;
-
V
-
V
-
:
r
YPE
DB
25
«
-
•
AIR
CIRCUIT
BREAKER
Mmmm
i
.
'
i
r
.
:
•
Vs
-
.
\
\
•
'
*
V
?
:
:
V
*
:
•
•
V
.
;
-
i
INT
.
RATING
25000
AMPS
.
FOR
.
CURRENT
RATING
Ut
251
)
D C
OVER
CURRENT
TRIP
N
.
P
;
.
.
>
l
!
..
:
.
ft
i
?
-
.
t
'
vY
..
.
A
*
:
:
;
‘
‘
.
-
y
.
;
Li
!
ay
/
V
'
.
yM
:
:
,
/
XYP
-
Y
!
-
<
.
\
•
•
t
VOI
-
TAGE
600
V
'
A
.
C
:
>
!
,
-
V
“
v
*
—
-
•
,
f
•
>
.
.
<
,
•
.
-
>
.
-
V
-
.
/
/
/
.
J
:
)
>
IS
.
.
/
•
tT
-
:
•
•
•
>
v
*
v
.
'
.
>
:
•
SERIAL
%
•
>
.
/
•
V
'
•
•
V
‘
T
*
>
r
•
:
v
4
.
/
.
i
V
M
,
j
.
•
’
.
.
PATigfa
;
T
:
gy
:
|
jl
^
090
/
^
96
^
43
‘
,
42
LtOl
566
lf
^
:
036284
V
^
Q
3
&
054
v
2
M
74
^
v
216
Q
68
^
-
«
•
.
*
/
I
,
f
:
i
-
:
.
•
:
V
:
•
<
•
^
Y
:
-
..
•
v
-
'
.
J
-
.
*
,
..
k
-
-
.
v
,
»
•
'
'
i
•
J
-
r
V
-
•
.
.
.
i
:
.
V
.
-
•
.
2
•
•
>
•
'
J
:
•
r
-
Vfc
-
V
:
OV
-
V
;
-
.
-
V
‘
.
-
•
:
ii
V
.
>
••
'
A
.
r
.
Ci
:
..
'
•
-
!
.
f
-
4
*
f
*
;
For
a
permanent
record
,
it
is
suggested
that
all
nameplatjb
V
"
.
,
.
Y
-
.
-
/
vV
/
t
i
t
•
s
i
.
"
'
/
'
9
’
•
•
A
'
'
’
•
f
:
VU
5
!
.
>
•
•
r
-
1
i
.
i
•
|
-
-
'
T
i
;
;
k
•
'
•
;
’
i
-
•
;
•
/
*
.
-
.
~
-
j
•
.
K
"
.
i
r
*
'
i
:
vv
"
S
?
J
Vi
IS
4
/
s
/
s
.
,
ifcf
SM
.
i
.
•
.
•
-
J
:
.
£
.
/
.
.
/
/
•
••
:
/
/
.
.
'
i
>
.
.
v
:
;
!
i
:
m
v
1
.
..
Courtesy of NationalSwitchgear.com

r
•
I
.
B
.
S
5
-
225
-
1
A
I
INSTALLATION
•
MAINTENANCE
"
De
-
ion
"
JUR
CIRCUIT
BREAKERS
Types
DB
-
15
and
DB
-
25
j
"
.
•
600
Volts
A
-
C
250
Volts
D
-
C
U
iv
i
:
:
.
interrupting
Rating
Type
DB
-
25
25
/
000
Amperes
Type
DB
-
15
15
/
000
Amperes
7
.
i
'
i
Rating
of
Series
Coils
f
:
«
.
Type
DB
-
25
(
Amperes
)
35
/
50
/
70
/
90
,
100
,
125
150
,
175
,
200
,
225
,
250
,
300
,
350
,
400
,
500
,
600
Type
DB
-
15
(
Amperes
)
15
,
20
,
25
,
35
,
50
,
<
•
v
-
/
125
,
90
,
100
,
70
,
150
,
175
,
200
,
225
;
:
/
!
WESTING
HOUSE
ELECTRIC
CORPORATION
r
r
SWITCHGEAR DIVISION
li
£
EAST
PITTSBURGH
PLANT
SUPERSEDES
I
.
B
.
35
-
225
-
1
EAST
PITTSBURGH
,
PA
.
EFFECTIVE
SEPTEMBER
,
I
960
(
Rep
.
10
-
81
)
•
Printed
in
U
.
S
.
A
.
9
u
'
Courtesy of NationalSwitchgear.com

TABLE
OF
CONTENTS
RECEIVING
,
HANDLING
AND
STORING
Page
7
Part
One
7
Inspection
Storing
.
.
.
7
INSTALLATION
Pages
8
-
12
Part
Two
8
Connections
Enclosures
. .
8
MAINTENANCE
Pages
13
-
28
Part
Three
Pole
Unit
Contacts
Maintenance
of
Contacts
. .
Operating
Mechanism
Closing
Solenoid
.
.
Overcurrent
Tripping
Device
Classification
as
to
Time
-
Current
Characteristics
Operation
Adjustment
of
Calibration
Settings
Installation
and Removal
Maintenance
Control
Relay
.
'
Shunt
Trip
Attachment
Undervoltage
Trip
Attachment
Undervoltage
Time
Delay
Attachment
Reverse
Current
Trip
Attachment
.
,
Field
Discharge
Switch
Auxiliary
Switch
Alarm
Switch
Attachment
Electric
Lockout Attachment
Key
Interlock
Attachment
Terminal
Block
13
13
13
13
i
13
15
15
16
18
18
18
18
19
20
22
22
25
25
26
26
28
28
i
2
Courtesy of NationalSwitchgear.com

f
-
-
V
LB
.
35
-
225
-
1
A
“
m
”
AIR
CIRCUIT
BREAKERS
Z
r
.
V
ILLUSTRATIONS
/
V
LIST
s
’
:
&
-
Page
Figure
1
Type
"
DB
"
Air
Circuit
Breaker
—
Exploded
View
2
DB
-
15
Outline
Dimensions
and
Mounting
Details
3
DB
-
25
Outline
Dimensions
and
Mounting
Details
4
Typical
Wiring
Diagrams
—
Type
"
DB
"
Circuit
Breaker
5
Ventilated
Enclosures
—
Outline
Dimensions
and
Mounting
Details
.
.
6
Cross
-
Sectional
View
of
Type
DB
-
25
Circuit
Breaker
7
Overcurrent
Tripping
Device
-
Location
7
A
Overcurrent
Tripping
Device
—
Construction
Details
8
Tripping
Characteristics
of
DB
-
15
and
DB
-
25
Overcurrent
Tripping
Devices
with
Long
Time
Delay
and
Instantaneous
Elements
8
A
Time
-
Current
Characteristics
of
DB
-
25
Circuit
Breakers
Equipped
with
Typical
Overcurrent
Tripping
Devices
for
Motor
Starting
and
Selective
Operation
...
.
.
.
.
.
.
.
.
9
Control
Relay
—
Location
,
Adjustment
,
and
Construction
Details
—
10
Shunt
Trip
Attachment
—
-
Location
and
Construction
Details
.
11
Undervoltage
Trip
Attachment
—
Location
and
Construction
Details
.
12
Undervoltage
Time
Delay
Attachment
—
Location
12
A
Undervoltage
Time
Delay
Attachment
—
Construction
Details
13
Reverse
Current
Trip
Attachment
—
Location
.
13
A
Reverse
Current
Trip
Attachment
—
Construction
Details
14
Field
Discharge
Switch
—
Location
and
Construction
Details
15
Auxiliary
Switch
—
Location
15
A
Auxiliary
Switch
—
Construction
Details
16
Alarm
Switch
Attachment
—
Location
16
A
Alarm
Switch
Attachment
—
Construction
Details
17
Electric
Lockout
Attachment
—
Location
and
Construction
Details
.
..
18
Key
Interlock
Attachment
—
Location
and
Construction
Details
19
Terminal
Block
Attachment
—
Construction
Details
u
v
.
.
5
>
6
.
9
r
.
10
•
i
-
li
*
*
••
•
12
14
15
*
/
'
•
r
-
-
-
1
15
f t
,
:
-
16
~
Y
&
;
17
19
20
'
iv
K
-
21
22
r
.
:
y
-
22
&
••
•
&
23
iv
-
23
-
*
•
li
24
*
fe
-
25
25
V
.
.
•
26
p
-
'
26
*
T
-
;
27
SV
-
f
-
V
.
I
*
'
-
;
’
28
¥
:
V
28
11
.
r
’
&
v
:
:
r
;
.
T
"
:
/
$
I
ft
•
f
,
;
V
;
£
Be
r
-
sr
&
£
K
Courtesy of NationalSwitchgear.com

«
i
:
•
:
i
I
!
i
l
>
\
!
5
:
:
m
ii
?
:
;
1
m
.
tfs
?
N
:
1
£
,
r
<
i
.
£
i
I
fii
r
I
r
-
4
Courtesy of NationalSwitchgear.com

m
mu
:
\
'
I
.
B
.
35
-
225
-
1
A
“
DB
"
AIR
CIRCUIT
BREAKERS
¥
¥
ft
;
'
p
,
S
#
:
'
.
/
rft
-
ft
’
fg
-
v
m
£
*
1
;
Westinghonse
TYPE
"
DB
"
AIR
CIRCUIT
BREAKER
t
A
•
Type
"
DB
77
aix
circuit
breaker
is
designed
to
give
continuous
and
reliable
service
as
the
protective
link
between
the
power
source
and
associated
pro
-
ductive
equipment
.
This
breaker
is
built
to
operate
with
a
minimum
of
main
-
tenance
,
while
at
the
same
time
its
simplified
construction
permits
maximum
accessibility
for
inspection
and
adjustment
when
required
.
The
ease
with
which
attachments
may
be
added
or
removed
is
an
outstanding
feature
of
the
UDB
"
design
.
For
the
greatest
measure
of
safety
to
operating
personnel
and
also
to
min
-
imize
maintenance
requirements
,
the
breaker
should
be
mounted
in
an
enclosure
suitable
to
local
operating
conditions
.
A
selection
of
standard
enclosures
is
available
for
various
applications
.
H
:
w
V
J
.
•
;
important
:
To
assure
proper
functioning
,
inspect
each
breaker
at
reg
-
ular
intervals
in
accordance
with
a
systematic
maintenance
schedule
.
The
frequency
and
character
of
the
inspections
will
for
the
most
part
be
determined
by
the
severity
of
the
duty
performed
.
The
minimum
requirements
,
however
,
should
consist
of
a
light
monthly
inspection
,
with
a
thorough
inspection
semi
-
annually
.
Occasional
checks
on
cali
-
bration
as
well
as
on
coordination
and
freedom
of
all
moving
parts
,
must
be
included
in
the
maintenance
schedule
.
Consult
Westinghouse
engineering
and
service
personnel
for
recommendations
pertaining
to
special
operating
or
maintenance
conditions
.
f
;
i
t
j
5
Courtesy of NationalSwitchgear.com

'
i
I
.
li
!
!
:
i
?
i
i
<
t
r
;
I
*
!
•
l
:
i
if
i
i
i
I
i
/
i
I
il
if
i
i
ii
?
•
FIG
.
1
.
Type
“
DB
”
Air
Circuit
Breaker
—
Exploded
View
i
u
i
Courtesy of NationalSwitchgear.com

6
|
fr
-
%
:
;
«
•
-
I
.
B
.
35
-
225
-
1
A
“
DB
”
AIR
CIRCUIT
BREAKERS
FART
ONE
x
-
;
\
-
1
.
RECEIVING
,
HANDLING
AND
STORING
&
a
.
Observe
whether
all
parts
are
in
proper
alignment
and
move
freely
.
’
b
»
Make
certain
that
the
studs
have
not
been
forced
out
of
alignment
.
c
«
Be
sure
that
the
contacts
are
clean
and
.
/
properly
aligned
.
For
a
description
of
contact
align
-
ment
,
refer
to
"
Contacts
!
'
,
page
13
.
3
.
If
the
contacts
are
in
alignment
and
all
parts
move
freely
,
continue
the
clockwise
rotation
until
the
breaker
is
latched
,
4
«
Return
the
manual
operating
handle
to
the
neutral
position
,
then
rotate
counterclockwise
to
trip
the
breaker
.
:
a
.
The
toggle
linkage
should
collapse
and
the
moving
contact
assembly
move
freely
to
the
full
open
position
.
This
should
be
followed
immediate
-
ly
by
complete
resetting
of
the
links
in
the
toggle
mechanism
as
the
handle
is
returned
to
the
neutral
position
.
Type
"
DB
"
air
circuit
breakers
,
with
all
attach
-
ments
mounted
in
place
,
are
shipped
in
wooden
crates
or
cardboard
containers
.
Important
:
:
To
avoid
damage
to
the
break
-
ers
,
do
not
use
hooks
in
handling
.
Net
weights
of
Types
DB
-
15
and
DB
-
25
fixed
breakers
are
given
in
Table
No
.
1
below
.
Add
15
lbs
.
for
drawout
breakers
.
f
U
fte
'
•
V
1
Table
No
.
h
NET
WEIGHTS
y
DB
-
15
DB
-
25
TYPE
2
-
Pole
2
-
Polo
3
-
Polo
3
-
Pole
80
lbs
.
100
lbs
.
60
lbs
.
75
lbs
.
70
lbs
.
85
lbs
.
90
lbs
.
110
lbs
.
Manual
Eleatric
Immediately
upon
receipt
,
examine
the
shipment
for
any
loss
or
damage
incurred
during
transit
.
If
injury
or
rough
handling
is
evident
,
file
a
damage
claim
at
once
with
the
transportation
company
and
notify
the
nearest
Westinghouse
Sales
Office
.
When
unpacking
,
be
sure
that
no
loose
parts
are
missing
or
left
in
the
packing
material
.
Report
all
shortages
at
once
.
Blow
out
any
dust
or
particles
of
packing
material
that
may
have
accumulated
on
the
circuit
breaker
parts
.
Remove
tape
from
top
of
arc
chutes
.
hm
The
links
must
always
be
free
to
move
without
friction
or
binding
.
5
.
Check
the
attachments
for
operation
in
accord
-
ance
with
the
appropriate
instructions
as
given
under
"
Maintenance
"
,
Part
Three
of
this
book
„
6
«
All
bearings
and
latch
surfaces
of
the
operat
-
ing
mechanism
should
be
lubricated
approximately
every
*
10
,
000
operations
.
Molybdenum
disulfide
mixed
with
carbon
tetrachloride
(
Wqstinghouse
process
specification
291
401
)
is
recommended
.
The
carbon
tetrachloride
evaporates
,
leaving
a
thin
film
of
molybdenum
disulfide
on
the
bearings
and
pins
.
The
molybdenum
disulfide
is
non
-
greasy
and
consequently
avoids
the
accumulation
of
dust
.
INSPECTION
The
"
DB
"
breaker
assembly
consists
of
a
coor
-
dinated
group
of
sub
-
assemblies
mounted
on
a
steel
supporting
panel
.
(
See
Fig
.
1
)
.
The
complete
break
-
er
assembly
is
to
be
mounted
with
the
steel
panel
in
a
vertical
position
.
All
inspections
for
proper
operation
should
,
therefore
,
be
made
with
the
break
-
er
in
this
position
.
Final
inspection
should
prefer
-
ably
be
made
with
the
breaker
in
its
permanent
mounting
.
Inspect
the
breaker
as
follows
:
1
.
Raise
and
lower
the
trip
bar
by
hand
to
make
sure
that
it
does
not
bind
.
2
.
Rotate
the
manual
operating
handle
slowly
in
a
clockwise
direction
to
move
the
coxitacts
toward
the
closed
position
.
STORING
If
circuit
breakers
are
not
to
be
installed
in
their
permanent
location
at
once
,
they
should
be
care
-
fully
inspected
for
loose
or
damaged
parts
and
then
stored
in
a
clean
dry
place
in
an
upright
position
to
avoid
damage
to
the
circuit
breaker
parts
.
A
covering
of
paper
will
prevent
dust
from
settling
on
the
circuit
breaker
parts
and
is
preferred
to
packing
or
other
materials
that
are
apt
to
absorb
moisture
.
7
Courtesy of NationalSwitchgear.com

PART
TWO
I
s
;
i
r
!
ti
!
INSTALLATION
!
:
l
Hi
that
the
mounting
dimensions
differ
and
should
be
obtained
from
the
appropriate
outline
drawing
.
The
following
procedure
applies
to
all
enclosures
:
1
.
Connect
the
entrance
cables
first
.
Whenever
possible
,
the
power
cables
should
be
connected
to
the
top
terminals
to
remove
voltage
from
the
over
-
current
attachments
when
the
breaker
is
open
.
The
cables
can
be
connected
to
the
nearest
terminal
,
or
to
the
opposite
terminal
as
shown
in
Fig
.
5
.
Tin
.
the
ends
of
the
cable
to
prevent
the
formation
of
copper
oxide
.
Tighten
the
clamp
bolt
securely
and
lock
with
the
lock
nut
.
.
.
2
.
Control
wires
should
run
along
the
left
side
of
the
enclosure
below
the
rail
.
Connect
to
the
terminal
block
or
auxiliary
switch
by
running
be
-
tween
the
breaker
platform
and
the
rail
in
front
of
the
wheel
,
after
the
breaker
is
bolted
in
place
.
When
removing
the
breaker
,
disconnect
the
control
wiring
from
the
terminal
block
or
auxiliary
switch
and
lay
in
the
bottom
of
the
enclosure
,
out
of
the
way
of
the
breaker
.
3
.
Roll
the
breaker
into
the
enclosure
until
the
four
mounting
bolts
engage
the
mounting
brackets
.
The
mounting
bolts
are
used
as
jacks
to
pry
the
finger
clusters
into
engagement
with
the
terminals
,
and
consequently
each
bolt
should
be
tightened
*
4
inch
in
succession
until
the
breaker
panel
is
tight
against
the
mounting
brackets
.
The
same
procedure
should
be
followed
in
removing
the
breaker
,
i
.
e
.
,
remove
each
bolt
*
4
Inch
in
succession
until
they
drop
free
,
4
.
Always
rotate
the
operating
handle
to
the
tripped
position
before
removing
the
front
cover
.
A
trip
rod
(
not
shown
in
Fig
.
S
)
holds
the
breaker
trip
free
when
the
front
cover
is
off
,
When
operating
the
breaker
in
the
test
position
(
front
wheels
engag
-
ing
the
slot
in
the
rail
)
,
it
is
unnecessary
to
hold
this
rod
in
manually
to
secure
closure
of
the
breaker
.
When
fastening
the
cover
in
place
,
draw
the
four
cover
bolts
down
firmly
.
Type
"
DB
"
circuit
breakers
are
furnished
as
com
-
plete
unit
assemblies
and
the
installation
consists
of
:
(
1
)
bolting
them
to
the
supporting
framework
or
structure
;
(
2
)
connecting
the
current
-
carrying
cables
or
bus
bars
;
and
(
3
)
completing
any
second
-
ary
control
wiring
that
may
be
necessary
.
Cautions
During
installation
,
the
circuit
breaker
should
be
in
the
open
position
.
Be
sure
to
de
-
energize
the
load
and
control
leads
to
be
connected
,
and
also
the
section
of
the
switchboard
where
the
installation
is
being
made
.
Mounting
dimensions
and
details
of
front
enclo
-
sure
cutouts
are
shown
in
Figs
.
2
and
3
.
To
prevent
distortion
of
the
breaker
panel
,
the
supporting
structure
should
be
checked
for
align
-
ment
.
«
CONNECTIONS
Typical
circuit
breaker
wiring
diagrams
are
shown
in
Fig
.
4
.
The
connecting
cables
or
bus
bars
should
have
adequate
current
-
carrying
capacity
,
otherwise
,
heat
will
be
conducted
to
the
circuit
breaker
resulting
in
possible
excessive
temperature
rise
.
Connecting
cables
or
bus
bars
must
be
sup
-
ported
so
that
the
circuit
breaker
studs
will
not
be
subjected
to
unnecessary
stresses
.
The
circuit
breaker
studs
and
all
connections
should
be
clean
,
smooth
,
and
free
from
burrs
to
assure
full
contact
area
.
They
should
be
firmly
clamped
or
bolted
in
place
to
prevent
excessive
heating
.
ii
ENCLOSURES
The
terminal
panel
and
breaker
arrangement
shown
in
Fig
.
5
apply
specifically
to
ventilated
enclosures
.
The
same
arrangement
is
used
for
all
other
enclosures
(
weatherproof
,
subway
,
explosion
-
proof
,
!
dust
!
tight
and
semi
-
dust
tight
)
except
ii
i
Courtesy of NationalSwitchgear.com