Miller CP-750 User manual

February
1975
FORM:
OM-238
MODEL
C P.7
50
CP-1000
STOCK
NO.
900 860
900
869
MODEL/STOCK
NO.
SERIAL/STYLE
NO.
DATE
PURCHASED
ADDITIONAL
COPY
PRICE
40
CENTS
Effective
with
Serial
No.
HE819991

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WARRANTY
C
MILLER
Electric
Mfg.
Co.,
Appleton,
Wisconsin,
warrants
all
new
equipment
to
be free
from defects
in
Ca
a
a
material
and
factory
workmanship
for the
periods
indicated
below,
provided
the
equipment
is installed
and
a
a
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a
-
a a
operated according
to
manufacturers
instructions,
CC
aa
a
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a
MILLER Electric
Mfg.
Co.s
obligation,
under
this
warranty,
is
limited to
replacingor
repairing
any
defective
I
part
or
correcting
any
manufacturing
defect
without
charge
during
the
warranty
period
if
MILLERS
inspec
a
tion confirms
the existence
of
such
defects. MILLERS
option
of
repair
or
replacement
will be
fob,
factory
at
a
a
C
a
a
Appleton,
Wisconsin
or
fob,
a
MILLER
authorized service
facility,
and
therefore
no
compensation
for
trans-
c
a
portation
costs
of
any
kind
will be
allowed.
a
C)
C
a
C 3
C
a
The
warranty
period, beginning
on
the date
of
sale
to
the
original
purchaser-user
of the
equipment,
will
be
as
C
a
a
C
3
a
follows:
3
a
a
1. Arc
welders,
power
sources,
and
components

1
year
C
C
a
C3
C
a
2.
Original
main
power
rectifiers

3
years
(unconditionally)
3.
MHFC-L1
Feeder,
MHG-35C1,
20E,
20K,
C
(3
and
all
guns
and torches

90
days
c
C
3
a
~
4.
All
other
Millermatic
Feeders

1
year
5.
Mag-Diesel
engine
on
DEL-200

6 months
C
3
6.
All
other
engines

1
year
C
C) C)
,
Engine
Warranties
are
covered
by
the
engine
manufacturers,
subject
to
their
procedures
and
to
be
handled
C)
through
their
authorized local
Service Stations
or
agencies.
No
warranty
will
be
made
in
respect
to
trade
C)
,
accessories,
such
being
subject
to
the
warranties
of
their
respective
manufacturers.
C
C)
C)
C
C)
C)
a
MILLER Electric
Mfg.
Co. will
not
be
liable
for
any
loss
or
consequential
damage
or
expense
accruing
c
~
directly
or
indirectly
from
the
use
of
equipment
covered
in
this
warranty.
C)
C)
C)
C
~
This
warranty
supersedes
all
previous
MILLER
warranties
and
is
exclusive
with
no
other
guarantees
or
C
C)
c
C
)
warranties
expressed
or
implied.
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SECTION
1-SAFETY
RULES
FOR
OPERATION
OF
ARC WELDING
POWER
SOURCE
1-1.
INTRODUCTION
We
learn
by
experience.
Learning
safety
through
personal
experience
like
a
child
touching
a
hot stove
is
harmful,
waste
ful,
and
unwise. Let
the
experience
of
others
teach
you.
Safe
practices developed
from
experience
in
the
use
of
weld
ing
and
cutting
are
described
in
this
manual.
Research.
devel
opment,
and
field
experience
have
evolved
reliable
equipment
and
safe
installation,
operation,
and
servicing practices.
Acci
dents
occur
when
equipment
is
improperly
used
or
main
tained.
The
mason
for the
safe
practices
may
not
always
be
given.
Some
are
based
on
common
sense,
others
may
require
technical
volumes
to
explain.
It
is
wiser
to
follow
the
rules.
Read
and
understand
these
safe
practices
before
attempting
to
install,
operate,
or
service
the
equipment
Comply
with
these
procedures
as
applicable
to
the
particular
equipment
used
and
their
instruction
manuals,
for
personal
safety
and
for
the
safety
of
others.
Failure
to
observe
these
safe
practices
may
cause
serious
in
jury
or
death.
When
safety
becomes
a
habit,
the
equipment
can
be
used
with confidence.
Responsibilities
of
installer,
user,
and serviceman.
Installa
tion,
operation, checking,
and
repair
of this
equipment
must
be
done
only by
a
competent
person,
experienced
with
such
equipment.
These
safe
practices
are
divided
into
two
Sections:
1
General
Precautions,
common
to
arc
welding
and
cutting;
and
2-
Arc
Welding
(and
CuttingUonly).
Reference
standards:
Published
Standards
on
safety
are
also
available
for additional
and
more
complete procedures
than
those
given
in this
manual.
They
are
listed
in
the
Standards
Index
in
these
safety
rules.
ANSI
249.1
is the
most
complete.
The
National
Electrical
Code,
Occupation
Safety
and
Health
Administration,
local
industrial
codes,
and
local
inspection
requirements
also
provide
a
basis
for
equipment
installation,
use,
and
service.
GENERAL
PRECAUTIONS
Burn
Prevention
Wear
protective
clothing
-
leather
(or
asbestos)
gauntlet
gloves,
hat,
and
high
safety-toe
shoes.
Button
shirt collar
and
pocket
flaps,
and
wear
cuffless
trousers
to
avoid
entry
of
sparks
and
slag.
Wear
helmet
with
safety
goggles
or
glasses
with side
shields
underneath,
appropriate
filter
lenses
or
plates
(protected
by
clear
cover
glass).
This is
a
MUST
for
welding
or
cutting,
(and
chipping(
to
protect
the
eyes
from
radiant
energy
and
flying
metal.
Replace
cover
glass
when
broken,
pitted,
or
spattered.
See 1-3A.
Avoid
oily
or
greasy
clothing.
A
spark may
ignite
them.
Hot
metal such
as
electrode
stubs
and
workpieces
should
never
be
handled without
gloves.
Medical
first
aid
and
eye
treatment.
First aid
facilities
and
a
qualified
first
aid
person
should
be
availthle
for
each
shift
unless
medical
facilities
are
close
by
for
immediate
treatment
of
flash
burns
of
the
eyes
and
skin
burns.
Ear
plugs
should be
worn
when
working
on
overhead
or
in
a
confined
space.
A
hard
hat
should
be
worn
when others
work
overhead.
Flammable
hair
preparations
should
not
be
used
by
persons
intending
to
weld
or
cut.
B.
Toxic
Fume
Prevention
Adequate
ventilation.
Severe
discomfort
illness
or
death
can
result
from
fumes,
vapors,
heat
or
oxygen
enrichment
or
depletion
that
welding
(or
cutting(
may
produce.
Prevent
them
with
adequate
ventilation
as
described
in
ANSI Stan.
dard
249.1
listed
1 in
Standards
index.
NEVER
ventilate
with
oxygen.
Lead, cadium,
zinc,
mercury,
and
beryllium
bearing
and
simi
lar
materials,
when
welded
(or
cut)
may
produce
harmful
concentrations
of toxic fumes.
Adequate
local
exhaust
venti
lation
must
be
used,
or
each
person
in
the
area
as
well
as
the
operator
must
wearan
air-supplied
respirator.
For
beryllium,
both
must
be
used.
Metals
coated
with
or
containing
materials
that
emit
toxic
fumes
should
not
be
heated unless
coating
is
removed
from
the work
surface,
the
area
is well
ventilated,
or
the
operator
wears an
air-supplied
respirator.
Work
in
a
confined
space
only
while
it is
being
ventilated
and,
if
necessary,
while
wearing
an
air-supplied
respirator.
Gas
leaks
in
a
confined
space
should
be
avoided. Leaked
gas
in
large
quantities
can
change
oxygen
concentration
danger
ously.
Do
not
bring
gas
cylinders
into
a
confined
space.
Leaving
confined
space,
shut
OFF
gas
supply
at
source.
The
space
will then be safe
to
re-enter,
if
downstream
valves
have
been
accidently
opened
or
left
open.
Vapors
from chlorinated
solvents
can
be
decomposed
by
the
heat
of
the
arc
(or
flame)
to
form
PHOSGENE,
a
highly
toxic
gas,
and
other
lung
and
eye
irritating products.
The ultra
violet
(radiant)
energy
of the
arc can
also
decompose
tn
chloroethylene
and
perchloroethylene
vapors
to
form
phos
gene.
DO NOT
WELD or
cut
where solvent
vapors
can
be
drawn
into the
welding
or
cutting
atmosphere
or
where
the
radiant
energy
can
penetrate
to
atmospheres
containing
even
minute amounts
of
trichlorethylene
or
perchlorethylene.
C.
Fire
and
Explosion
Prevention
Causes of
fire
and
explosion
are:
combustibles
reached
by
the
arc,
flame,
flying
sparks,
hot
slag
or
heated
material;
misuse
of
compressed
gases
and
cylinders;
and short
circuits.
Be
aware
that
flying
sparks
or
falling
slag
can
pass
through
cracks,
along
pipes,
through
windows
or
doors,
and
through
wall
or
floor
openings,
out
of
sight
of the
goggled
operator.
Sparks
and
slag
can
fly
35
feet.
To
prevent
fires
and
explosion:
Keep
equipment
clean and
operable,
free
of
oil,
grease.
and
(in
electrical
parts)
of
metallic
particles
that
can
cause
short
circuits.
If
combustibles
are
in
area,
do
NOT
weld
or
cut.
Move
the
work
if
practicable,
to
an
area
free of
combustibles.
Avoid
paint
spray
rooms,
dip
tanks,
storage
areas,
ventilators.
If the
work
can
not
be
moved,
move
combustibles
at
least
35
feet
away
out
of reach
of
sparks
and
heat: or
protect
against
ignition
with
suitable
and
snug-fitting,
fire-resistant
covers
or
shields.
Walls
touching
combustibles on
opposite
sides
should
not
be
welded
on
(or
cut).
Walls,
ceilings,
and
floor
near
work
should be
protected
by
heat-resistant
covers
or
shields.
Fire
watcher
must
be
standing
by
with
suitable
fire
ex
tinguishing
equipment
during
and
for
some
time after
weld
ing
or
cutting
if:
a.
appreciable
combustibles
(including
building
construc
tion)
are
within
35
feet
b.
appreciable
combustibles
are
further than
35
feet but
can
be
ignited
by
sparks
c.
openings
(concealed
or
visible)
in floors
or
walls
within
35
feet
may
expose
combustibles
to
sparks
d.
combustibles
~jacent
to
walls,
ceilings,
roofs,
or
metal
partitions
can
be
ignited
by
radiant
or
conducted
heat.
Hot
work
permit
should be obtained
before
operation
to
ensure
supervisors
approval
that
adequate
precautions
have
been
taken.
After
work
is
done,
check that
area
is free
of
sparks,
glowing
embers,
and
flames.
An
empty
container
that
held
combustibles,
or
that
can
pro
duce
flammable
or
toxic
vapors
when
heated,
must
never
be
welded
on
or
cut,
unless
container
has
first been
cleaned
as
described
in
AWS Standard
A6.O,
listed
3
in
Standards
index.
1-2.
A.
OM-238
Page
1

possible
leak.
For
fuel
gas,
open
to
less
than
one
turn to
permit quick
emergency
shutoff.
Use
pressure
charts
(available
from
your
supplier)
for safe
and
efficient,
recommended
pressure
settings
on
regulators.
It
will
reduce
backfiring
and
chance
of
flashbacks.
Check
for
leaks
on
first
pressurization
and
regularly
there
after. Brush
with
soap
solution
(capful
of
Ivory
Liquid
or
equivalent
per
gallon
of
water).
Bubbles
indicate leak.
Clean
off
soapy
water
after
test;
dried
soap
is
combustible.
E.
User
Responsibilities
Remove
leaky
or
defective
equipment
from
service
immed
iately
and
repair
them
only
if
recommended
in
equipment
instruction manual.
Send
others
for
repair
to
manufacturers
designated
repair
center
where
special
techniques
and tools
are
used
by
trained
personnel.
Refer
to
User
Responsibilities
statement
in
equipment
manual.
F.
Leaving Equipment
Unattended
Close
gas
supply
at
source
and
drain
gas.
G.
Rope Staging-Support
Rope
staging-support
should
not
be
used for
welding
or
cut
ting
operation;
rope may
burn.
1-3.
ARC
WELDING
Comply
with
precautions
in
1-2
and
this
section.
Arc
Weld
ing,
properly
done,
is
a
safe
process,
but
a
careless
operator
invites trouble.
The
equipment
carries
high
currents
at
signifi
cant
voltages.
The
arc
is
very
bright
and hot.
Sparks fly.
fumes
rise,
ultraviolet and
infrared
energy
radiates,
weld
ments
are
hot,
and
compressed
gases
may
be
used.
The
wise
operator
avoids
unnecessary
risks
and
protects
himself
and
others
from accidents.
Precautions
are
described
here and
in
standards
referenced
in
index.
A.
Burn
Protection
Comply
with
precautions
in
1-2.
The
welding
arc
is
intense
and
visibly
bright.
Its radiation
can
damage
eyes,
penetrate
lightweight clothing,
reflect
from
light-colored
surfaces,
arid
burn
the skin and
eyes.
Skin
burns
resemble
acute
sunburn,
those
from
gas-shielded
arcs are
more
severe
and
painful.
DONT GET
BURNED;
COMPLY
WITH
PRECAUTIONS.
1.
Protective
Clothing
Wear
long-sleeve
clothing
(particularly
for
gas-shielded
arc) in
addition
to
gloves,
hat,
and
shoes (1-2A). As
necessary,
use
additional
protective clothing
such
as
leather
jacket
or
sleeves,
flame-proof
apron,
and
fire-resistant
leggings.
Avoid
outergarments
of
untreated
cotton.
Bare
skin
protection.
Wear
dark,
substantial
clothing.
Button
collar
to
protect
chest
and
neck and button
pockets
to
pre
vent
entry
of
sparks.
2.
Eye
and Head
Protection
Protect
eyes
from
exposure
to
arc.
NEVER
look
at
an
elec
tric
arc
without
protection.
Welding
helmet
or
shield
containing
a
filter
plate
shade no.9
or
denser
must
be
used
when
welding.
Place
over
face
before
striking
arc.
Protect
filter
plate
with
a
clear
cover
plate.
Cracked
or
broken helmet
or
shield
should
NOT
be
worn;
radiation
can
pass
through
to
cause
burns.
Cracked,
broken,
or
loose
filter
plates
must
be
replaced
IM
MEDIATELY.
Replace
clear
cover
plate
when
broken,
pitted,
or
spattered.
Flash
goggles
with
side
shields
MUST
be
worn
under
the
helmet
to
give
some
protection
to
the
eyes
should
the helmet
not
be
lowered
over
the face
before
an
arc
is
struck.
Looking
at
an
arc
momentarily
with
unprotected
eyes
(particularly
a
high
intensity
gas-shielded
arc)
can cause
a
retinal
burn
that
may
leave
a
permanent
dark
area
in
the
field
of
vision.
3. Protection of
Nearby
Personnel
Enclosed
welding
area.
For
production welding,
a
separate
room
or
enclosed
bay
is
best.
In
open
areas,
surround
the
operation
with
low-reflective,
non-combustible
screens
or
panels.
Allow for
free
air
circulation, particularly
at
floor
level.
Viewing
the
weld.
Provide face
shields
for
all
persons
who
will
be
looking
directly
at
the weld.
Others
working
in
area.
See
that
all
persons
are
wearing
flash
goggles.
Before
starting
to
weld,
make
sure
that
screen
flaps
or
bay
doors
are
closed.
B. Toxic
Fume
Prevention
Comply
with
precautions
in
1-28.
Generator
engine
exhaust
must
be vented
to
the outside
air.
Carbon
monoxide
can
kill.
C. Fire and
Explosion
Prevention
Comply
with
precautions
in
1-2C.
Equipments
rated
capacity.
Do
not
overload
arc
welding
equipment.
It
may
overheat
cables
and
cause
a
fire.
Loose
cable connections
may
overheat
or
flash and
cause a
fire.
Never
strike
an arc on
a
cylinder
or
other
pressure
vessel.
It
creates
a
brittle
area
that
can
cause
a
violent
rupture
or
lead
to
Such
a
rupture
later
under
rough
handling.
D.
Compressed
Gas
Equipment
Comply
with
precautions
in
1-2D.
E.
Shock
Prevention
Exposed
hot
conductors
or
other bare
metal
in the
welding
circuit,
or
in
ungrounded,
electrically-HOT
equipment
can
fatally
shock
a
person
whose
body
becomes a
conductor.
DO
NOT
STAND, SIT,
LIE,
LEAN
ON,
OR
TOUCH
a
wet
sur
face
when
welding,
without
suitable
protection.
To
protect
against
shock:
Keep body
and
clothing
dry.
Never work
in
damp
area
with
out
adequate
insulation
against
electrical
shock.
Stay
on a
dry
duckboard,
or
rubber
mat
when
dampness
or
sweat
can
not be
avoided.
Sweat,
sea
water,
or
moisture between
body
and
an
electrically
HOT
part
-
or
grounded
metal
.
reduces
the
body
surface
electrical
resistance,
enabling dangerous
and
possibly
lethal
currents
to
flow
through
the
body.
1.
Grounding
the
Equipment
When
installing,
connect
the
frames
of
each
unit
such
as
welding
power
source,
control,
work
table,
and
water
circula
tor
to
the
building
ground.
Conductors
must
be
adequate
to
carry
ground
currents
safely. Equipment
made
electrically
HOT
by
stray
current
may
shock,
possibly
fatally.
Do
NOT
GROUND
to
electrical
conduit,
or
to
a
pipe
carrying
ANY
gas
or a
flammable
liquid
such as
oil
or
fuel.
Three-phase
connection.
Check
phase
requirement
of
equip
ment
before
installing.
If
only
3-phase
power
is
available.
connect
single-phase
equipment
to
only
two
wires of
the
3-phase
line.
Do
NOT
connect
the
equipment
ground
lead to
the
third
(live)
wire,
or
the
equipment
will become
electri.
cally
HOT
-
a
dangerous
condition
that
can
shock,
possibly
fatally.
Before
welding,
check
ground
~or
continuity.
Be
sure
conduc
tors
are
touching
bare
metal
of
equipment
frames
at
connec
tions.
If
a
line
cord
with
a
ground
lead
is
provided
with
the
equip
ment
for connection to
a
switchbox,
connect
the
ground
lead
to
the
grounded
switchbox.
If
a
three-prong
plug
is
added
for
connection to
a
grounded
mating
receptacle,
the
ground
lead
must
be
connected
to
the
ground
prong
only.
If the
line
cord
comes
with
a
three-prong
plug,
connect
to
a
grounded
mating
receptacle.
Never
remove
the
ground
prong
from
a
plug,
or
use
a
plug
with
a
broken
off
ground
prong.
Trademark
of
Proctor
& Gamble.
OM-238
Page
3

SECTION
2-
INTRODUCTION
Model
Rated
Welding
Current
Amperes
Open-Circuit
Voltage
Range
Maximum
Open-
Circuit
Voltage
Amperes
Input
At
Rated
LoadOutput60Hz.
Three Phase

230
Volts
460
Volts
kva
kw
.
Dimensions
(Inches)
Weight
(Pounds)
Net
Ship
Amperes
750
@
35
Volts
100%
Duty
Cycle
15-49
49
92 46
36.6
33.2
Height
-
56-1/2
Width
-
27-1/4
Depth
-
35-3/4
895
955
1000
Amperes
30
Volts
100%
Duty
Cycle
15-47
47
120
60
47.7
43.5
Height-56.1/2
Width
-
27-1/4
Depth
-
38
1145
1215
   
Figure
2-1.
Specifications
2-1.
GENERAL
This
manual
has
been
prepared especially
for
use
in
familiar
izing
personnel
with
the
design,
installation,
operation,
main
tenance,
and
troubleshooting
of
this
equipment.
All
informa
tion
presented
herein should be
given
careful consideration
to
assure
optimum performance
of
this
equipment.
2-2. RECEIVING-HANDLING
Prior
to
installing
this
equipment,
clean
all
packing
material
from around
the
unit
and
carefully
inspect
for
any
damage
that
may
have
occurred
during
shipment.
Any
claims
for
loss
or
damage
that
may
have occurred
in
transit
must
be
filed
by
the
purchaser
with the carrier.
A
copy
of
the bill
of
lading
________________________________________________________
and
freight
bill
will be
furnished
by
the
carrier
on
request
if
occasion
to
file
claim arises.
When
requesting
information
concerning
this
equipment,
it
is
essential
that
Model
Description
and/or
Stock
Number
and
Serial
(or
Style)
Numbers of the
equipment
be
supplied.
2-3.
DESCRIPTION
This
Unit
is
a
three-phase
welding
power
source
which
pro
duces
dc
welding
current.
This
welding
power
source
is
________________
designed
specifically
for
use
with
the
Gas
Metal-Arc
)MIG)
Welding
process.
2-4.
SAFETY
Under
this
heading,
explanatory
statements
will be
found
that
need
special
emphasis
to
obtain the
most
Before the
equipment
is
put
into
operation,
the
safety
sec-
efficient
operation
of the
equipment.
tion
at
the
front
of this
manual
should
be
reed
completely.
SECTION
3
-
INSTALLATION
3-1.
LOCATION
(Figure
3-1)
A
proper
installation Site
should be selected
for
the
welding
power
source
if
the
unit
is
to
provide
dependable
service,
and
remain
relatively
maintenance
free.
A
proper
installation
site
permits
freedom
of
air
movement
into
and
Out
of the
welding
power
source,
and
also
least
subjects
the
unit
to
dust,
dirt,
moisture,
and corrosive
vapors.
A
minimum of
18 inches
of unrestricted
space
must
be
main
tained
between
the
welding
power
source
front
and
rear
panels
and the
nearest
obstruction.
Also,
the
underside
of
the
welding
powe(
source
must be
kept
completely
free
of
obstructions.
The
installation
site
should
also
permit
easy
removal
of the
welding
power
source
outer enclosure
for
maintenance
functions.
place
an
r;
over
the
in
take
air
pas~ges
of
the
welding
power
source
as
this
would
restrict the volume of intake
air
and
thereby subject
the
welding
power
source
internal
components
to
an
overheating
condition
and
subsequent
failure.
War-
TB.039
388
ranty
is
void
if
any type
of
filtering
device
is
used.
i
Figure
3-1.
Dimensional
Drawing
This
will
help
avoid
possible injury
due
to
misuse
or
improper
welding
applications.
The
following
definitions
apply
to
CAUTION, IMPORTANT,
and
NOTE
blocks
found
throughout
this
manual:
1Irq~i~iiii.i~1
I
Under
this
heading,
installation,
operating,
and main
tenance
procedures
or
practices
will
be
found
that
if
not
carefully
followed
may
create
a
safety
hazard to
personnel
I
~J~=ANT
U
Under
this
heading,
installation,
operating,
and
main
tenance
procedures
or
practices
will
be
found
that
if
not
carefully
followed
may
result in
damage
to
equip
ment.
U
NOTE
1
U
U
U
5-1/2
OM-238
Page
5

Holes
are
provided
in the
welding
power
source
base
for
mounting
purposes.
Figure
3.1
gives
overall dimensions
and
the
base
mounting
hole
layout.
On
most
welding power
sources
a
lifting
device
is
provided
for
moving
the
unit.
However,
if
a
fork
lift
vehicle
is
used
for
lifting
the
unit,
be
sure
that the
lift
forks
are
long
enough
to
extend
completely
under
the
base.
IMPORTANT
The
use
of
lift
forks
too
short
to extend out
of
the
opposite
side
of
the
base
will
expose
internal
com
ponents
to
damage
should
the
tips
of the
lift forks
~
penetrate
the
bottom
of
the
unit.
3-2.
ELECTRICAL
INPUT
CONNECTIONS
NOTE
It is
recommended that
a
Line
Disconnect
Switch
be
installed
in
the
input
Circuit
to
the
welding
power
source.
This would
provide
a
safe
and
convenient
means
to
completely
remove
all
electrical
power
from
the
welding
power
source
whenever it is
necessary
to
~
perform
any
internal
function
on
the unit
CAUTION__j

Before
making
electrical
input
conons
to
the
welding
power source,
machinery
lockout
proce
dures should be
employed,
If
the
connection
is to be
made from
a
line disconnect
switch,
the
switch
should
be
padlocked
in
the
open
position.
If
the
connection
is
made from
a
fuse
box,
remove
the fuses from
the box
and
padlock
the
cover
in
the
closed
position.
If
lock
ing
facilities
are
not
available,
attach
a
red
tag
to
the
line
disconnect
switch
(or
fuse
box) to
warn
others
that
the circuit
is
being
worked
on.
A.
Input
Electrical
Requirements
This
welding power
source
is
designed
to
be
operated
from
a
three
phase,
60
Hertz,
ac
power
supply
which
has
a
line
voltage
rating
that
corresponds
with
one
of
the
primary
volt
ages
shown
on
the
welding
power
source
nameplate.
Consult
the local
electric
utility
if
there
is
any
question
about
the
type
of
electrical
system
available
at
the installation
site
or
how
proper
connections
to
the
welding
power
source
are
to
be
made.
B.
Input
Conductor
Connections
CAUTION__I!
1
Do
not connect
the
input
conducto~he
three-
phase
power
supply
until all
input
electrical
connec
~~ions
have
been made to
the
welding
power
source
It is
recommended that
the
input
conductors be
of
the
heavy
rubber covered
type
or
be
installed
in
solid
or
flexible
con
duit. Select
theproper
size
input
conductors
and
fuse from
Table
3-1.
Table
3-1.
Input
Conductor
and
Fuse
Size
Input
Conductor
Size.
A6IG
Fuse
Size
(AmperesjJ
Model 208V
230V 460V
575V
208V 230V
460V 575V
750
Amp
(81
181
(8)
175
150
70
60
1000
Amp
(8)
(81 181
200
200
90 80
Numbers
in
I
I
are
ground
conductor
sizes
Insert the three
input
conductors
plus
one
ground
conductor
through
the
access
hole
on
the
rear
panel.
This
hole will
accept
standard conduit
fittings.
See
Figure
3-2
for
hole
loca
tion
and
size.
NOTE
J
I
It is
recommended
that
a
terminal
lug
of
adequate
1
amperage
capacity
be
attached to
the
ends
of
the
input
and
ground
conductors.
The hole
diameter
in
the
terminal
lug
must
be
of
proper
size to
accommo
date
the
line
and
ground
terminal studs
on
the
primary

terminal
board.
Connect
the three
input
conductors to
the
terminals
on
the
primary
terminal
board
labeled
L
or
LINE
and
connect
the
ground
conductor to
the
terminal
labeled
GRD
(See
Figure
3-2).
The
remaining
end
of
the
ground
conductor
should
be
connected to
a
proper
ground.
Use whatever
grounding
method
that
is
acceptable
to
the
local
electrical
inspection
authority.
CAUTION

The terminal
labeled
GAD
is
connecte~e
welding
power
source
chassis
and
is for
grounding
purposes
only.
Do
not
connect a
conductor
from
the
terminal
labeled
GAD
to
any
one
of the
L
or
LINE
terminals~as
this
will result
in
an
electrically
hot
welding
power

source
chassis.
Figure
3-2.
Input
Conductor Connections
Input
Voltage
Jumper
Links
C.
Matching
The
Welding
Power
Source
To
The
Avail
able
Input
Voltage
The
input
voltage
umper
links
provided
on
the
primary
ter
minal
board
permit
the
welding
power
source
to
be
operated
from
various
line
voltages.
The
various
voltages
from
which
this
welding
power
source
may
be
operated
are
stated
on
the
welding
power
source
nameplate,
and
on
the
input
voltage
label.
See
Figure
3-2
for location.
The
input
voltage
jumper
links
on
this
welding
power
source are positioned
for
the
highest
of
the
voltages
stated
on
the
nameplate.
If
the
weld
ing
power
source
is
to
be
operated
from
a
line
voltage
which
is
lower than the
highest
voltage
for which
the
unit
was
de
signed,
the
jumper
links
will
have
to
be
moved
to
the
proper
position
before
operation
of the
welding
power
source
com
mences.
Figure
3-3 shows
the
various
positions
for
which
the
jumper
links
may
be
set
on
the
standard
welding
power
source.
If
the
input
voltages
on
the
welding
power
source
nameplate
differ
from
those
shown
in
Figure
3-3,
the
input
voltage
jumper
links
must
be
positioned
as
shown
on
the
in
put voltage
label.
Ground
Line Terminals
Terminal
TA-900
872-2A
Page
6

NOTE
If
only
one
jumper
link
is
required
on
each
of
the
grouped
terminals,
it is
recommended that the
unused
jumper
links
be
placed
across
the
terminals
which
are
to
be
used. This will
prevent
losing
the
jumper
links
which
are
not
required
for
this connection.
G~D.
~Li
~L2
'L3
______
013
922
Figure
3-3.
Input
Voltage Jumper
Link
Arrangement
3-3.
SECONDARY
CONNECTIONS
The
Positive
and
Negative
secondary
terminals
are
located
behind the
lower
front
access
panel.
See
Figure
4-1 for
loca
tion
of the
terminals.
The
access
panel
which
covers
the
secondary
terminals
is
secured
by
two
fasteners.
To
open
the
access
panel,
rotate
the
fasteners
counterclockwise
one
full
turn.
Likewise,
to
close
the
panel,
rotate
the fasteners
clockwise one
full
turn.
A.
Welding
Cables
It
is
recommended
that the
welding
cables be
kept
as
short
as
possible,
placed
close
together,
and
be of
adequate
current
carrying
capacity.
The
resistance
of
the
welding
cables
and
connections
cause
a
voltage drop
which
is
added
to
the
volt.
age
of
the
arc.
Excessive
cable
resistance
may
result
in
over
loading
as
well
as
reducing
the maximum
current
output
of
which the
welding
power
source
is
capable.
The
proper opera
tion
of
any
arc
welding
power
source
is
to
a
great
extent
dependent
on
the
use
of
welthng
cables
and connections that
are
in
good
condition
and
of
adequate
size.
An
insulated
electrode
holder
must
be
used
to ensure
the
operators
safety.
Use
Table
3-2
as
a
guide
for
selecting
the
correct
welding
cable
size
for the
anticipated
maximum
weld
current
that
will
be
used.
Table
3-2
takes into
account
the total cable
length
for
the weld
circuit.
This
means
the
length
of the
Electrode
cable
that
connects
the
wire
feeder
to
the
welding
power
source
and the Work
or
ground
cable
between the
welding
power
source
and the
work
piece.
For
example:
If
the
Elec
trode
cable
is
75
feet
long
and the
work
Or
ground
cable
is
25
feet
long,
select
the
size cable
from
Table
3-2
that
is
recom
mended
for
100
feet.
In
a
situation
where
a
maximum
weld
current
of
150
amperes
is
anticipated,
No.
2
weld
cable
is
recommended
for
both the
Electrode
and Work cables.
WELDING
TOTA LLEN GTH OF CABLE
(COPPER
I
IN
WELD CIRCUIT
250 300 350
400
AMPERES
50 100 150 200
100
4
4
22
2
1
1/0 1/0
150
22
2
1
1/0
2/0
3/0
3/0
200
1
1
1
1/0
2/0
3/0 4/0
4/0
250
1/0 1/0 1/0
2/0 3/0
4/0
4/0
2-2/0
300
2/0 2/0 2/0 3/0
4/0 4/0
2-2/0
2.3/0
350
3/0 3/0 2/0
4/0
4/0
2-2/0 2-3/0
2-3/0
400
3/0
3/0 3/0 4/0
2-2/0
2-3/0 3.2/0
2-4/0
500
4/0 4/0
4/0
2-2/0
2-3/0
2.3/0 2-4/0
3-3/0
600
2.2/0 2-2/0
2-2/0
2-3/0
3-2/0 2-4/0
3.3/0
3.4/0
700
2-3/0 2.3/0 2.3/0
2-4/0
3-3/0
3-4/0
4-4/0
4-4/0
800
2.3/0
2-3/0
2-3/0
2.4/0
3-3/0
3-4/0
4.4/0 4-4/0
A002
623
NOTE:
A.
50 FEET OR
LESS.
8. CABLE SIZE IS
BASED ON DIRECT CURRENT
(DCI,
100%
DUTY
CYCLE AND EITHER
A
4
VOLTS
OR LESS
DROP OR A
CURRENT
DENSITY
OF NOT
OVER 300
CIRCULAR
MILS PER
AMP.
C. WELD
CABLE
INSULATION
WITH
A
VOLTAGE
RATING
TO
WITHSTAND
THE OPEN-CIRCUIT
VOLT.
AGE
IOCVI
OF
THE
WELDING POWER SOURCE MUST
BE
USED. WHILE
MOST
WELDING
POWER
SOURCES
HAVE
AN
OPEN-CIRCUIT
VOLTAGE OF
LESS
THAN
100
VOLTS.
SOME WELDING POWER SOURCES OF
SPECIAL DESIGN
MAY
HAVE
HIGHER OPEN-CIRCUIT
VOLTAGE.
3-4.
115
VOLTS
AC
RECEPTACLES
(Figure
4-1)
Two
receptacles,
both
labeled
115
VOLTS
AC,
are
provided
on
the
front
panel.
The
duplex
115
VOLTS
AC
receptacle
is
intended
to
be used for
operating
accessory
equipment.
The
three-pole
twistlock,
115
VOLTS
AC
receptacle
is
intended
to
be used
for
supplying
operating
power
to
a
control/feeder.
To
secure
the
corresponding
three-pole
plug
into
this
recep
tacle,
rotate
it
as
far
as
it
will
turn
in
a
clockwise direction.
I
Both
115
VOLTS
AC
Receptacles
and
CONTACTOR
CONTROL
Circuitry
are
protected
by
a
15
ampere
fuse
(F2)
which
is
located
on
the
front
panel.
If
it
should
become
necessary
to
replace
the
fuse,
ensure
that
a
fuse
of the
same
rating
is
used
for
a
replace
ment.
A
fuse
of
a
larger
rating
will
permit
overloading
of
the
115
volts
circuitry
and
thereby
cause
damage
to
the
welding
power
source.
3-5.
CONTACTOR
CONTROL CONNECTIONS
The
CONTACTOR CONTROL
Receptacle
located
on
the
front
panel,
is
a
two-pole,
twistlock, motor-base,
male
recep
tacle.
The
corresponding
plug
for
this
receptacle
is
supplied
with the
welding
power
source as
standard
equipment.
The
function
of
the
CONTACTOR
CONTROL
Receptacle
is
to
provide
a
connection
point
between the
remote contactor
control station
and
the
contactor
in
the
welding
power
source.
To
energize
the
contactor
from
a
remote
station,
the
remote
Station
must
be
able
to
supply
115
volts
ac
60
Hertz
electrical
power
to
this
receptacle.
To
connect
the
Remote
Contactor
Control
device
to
the
CONTACTOR CONTROL
Receptacle,
insert
the
two-pole
plug
from
the Remote
Contactor
Control
device
into
the
CONTACTOR
CONTROL
Receptacle
and
rotate
the
plug
as
far
as
it will
turn
in
a
clockwise direction.
The
plug
will
now
be
locked
in
the
receptacle
and
will
not
pull
out
under
stress.
Table 3-2.
Secondary
Cable
Sizes
230 VOLTS
460
VOLTS
I
I
OM-238
Pa~
7

SECTION
4-
FUNCTION OF
CONTROLS
4-5. CONTACTOR
CONTROL
RECEPTACLE
(Figure
4-1)
Whenever
a
Remote
Contactor
Control
is
to
be
used, make
connections
to
the
CONTACTOR CONTROL
Receptacle on
the
welding
power
source
as
instructed
in
item
3-5.
In
order
for
a
Remote
Contactor
Control
to
operate
the
contactor
in
the
welding
power
source,
the Remote
Contactor
Control
must
be
able
to
supply
115
volts
ac
to
the
CONTACTOR
CONTROL
Receptacle
whenever
weld
output
is
desired.
Also,
whenever
suspension
of weld
output
is
desired,
the
Remote
Contactor
Control
must
be
able
to
cut-off the 115
volts
ac
supply
to
the
receptacle.
NOTE
A
thermostat
is
connected
in
series
with the
con
tactor
coil
in
order
to
provide
overload
protection.
Should
an
overload condition
occur,
the
thermostat
would
open
and thus
cause
the
contactor
to
drop
out
and
suspend
weld
output.
Once
the thermostat
has
opened,
it
will
not
be
possible
to
energize
the
contactor
until
the-
welding
power
source
has cooled
to
a
proper
tempera
ture.
Usually
a
five
minute
idling
period
is
a
sufficient
period-of
time
for
the
welding
power
source
to
cool
in
order
to
permit
the
thermostat
to
close.
Figure
4-1. Front
Panel
View
Placing
the
POWER
Switch
in
the
ON
position
will
energize
the
welding
power
source
fan
and
control
circuitry
and
place
the
welding
power
source
in
a
ready-to-weld
status.
Placing
the
POWER
Switch in
the
OFF
position
will
shut the
welding
power
source
down.
Even
though
the
POWER
Switch is
in
the
OFF
posi
tion
and
the
welding
power
source
is
apparently
elec
trically
shut
down,
electrical
input
power
is
still
present
on
all
circuitry
up
to
the POWER
Switch.
To
completely
cut-off
all
electrical
power
to
the
welding
power
source,
it will
be
necessary
to
place
the line
disconnect switch
in
the
OFF
position
or
remove
the
inputcircuitfuses.
The
Range
Switch
provides
the
capability
of
being
able
to
select
from five
coarse
open-circuit
voltage
ranges.
The
maxi
mum
open-circuit
voltage
that
can
be
obtained
from each
switch
position
is
displayed
on
the
welding
power
source
nameplate.
chan
ge
the
pos
in
A
an
ge
Switch
while
welding
or
under
load
as
this
will
cause
the
contacts
of
the switch
to
arc.
Arcing
across
the
contacts
will
cause
the
contacts~to
become
pitted
and
thereby
eventually
to
become
inoperative.
4-3.
VOLTAGECONTROL(Figure4-1)
The
Voltage
Control
provides
the
capability
of
being
able
to
select the
desired
open-circuit
voltage
within
the
entire
range
of
the
welding
power
source.
Rotating
the
Voltage
Control
in
a
clockwise direction
will increase
the
open-circuit
voltage.
4-4.
OPEN-CIRCUIT
VOLTS
INDICATOR
(Figure
4-1)
An
indicator,
labeled
OPEN-CIRCUIT
VOLTS,
is
provided
on
the
front
panel
to
display
the
open-circuit
voltage
selec
ted.
The
reading
on
the
OPEN-CIRCUIT
VOLTS
Indicator
will
change
when
the
Voltage
Control
is
rotated.
4-6. METERS
(Figure
4-1)
The
welding
power
source
is
equipped
with
a
dc
ammeter
and
a
dc
voltmeter.
These
meters
are
internally
connected
to
the
welding
power
source
output
welding
terminals.
The
volt
meter
will
indicate
the
dc
voltage
at
the
secondary
terminals,
but
will
not
necessarily
indicate
the
actual
voltage
at
the
welding
arc.
If
the
welding
cables
are
excessively
long,
or
have
poor,
loose
connections,
the
difference
between
actual
arc
voltage
and
the
voltage
at
the
welding
power
source
secondary
terminals
may
be
considerable,
4-7. DUTY
CYCLE
(Figure
4-2)
zuutJ
Welding
power
sources
are
rated
on
a
percent
duty
cycle
based
on
10
minute
intervals.
For
example:
A
60
percent
duty
cycle
simply
means
that
the
welding
current
is
off for
4
minutes,
on
again
for
6
minutes,
and
so
on.
It
must
be
kept
in
mind
that
time
intervals
of
other
than 10
minutes
will
yield
different
test
rating
results.
As
the
output
is
reduced
or
increased,
the
duty
cycle
will
increase
or
decrease.
Figure
4-2
enables
the
operator
to
determine
the
safe
output
of
the
welding
power
source at various
duty
cycles.
,.,~&p
.....

,~5-0L_j_
E
1000

~__E

E

E

E
I I
u~j
icnn
1~sn
-~
r
~-
DC
Voltmeter DC Ammeter
\
Fuse
F2
Range
Switch
Open-Circuit
Volts
Indicator
Voltage
Control
Power
Switch
115
Volts AC
Duplex
Receptacle
115
Volts
AC
Twit
tlock
Receptacle
tactor
Control
Receptacle
TB-039
388
Negative
Secondary
Terminal
PositIve
Secondary
Terminal
I
I
4-i. POWER
SWITCH
(Figure
4-1)
U
I
4-2.
RANGE SWITCH
(Figure
4i)
IMPORTANT
Exceeding
the
indicated
duty
cycle
will
cause
the
welding
power
source to
overheat
thereby
causing

damage
to
the
welding
power
source.
LU
LU
0~
5
(3
0
-J
LU
0
15
20
25 30
%DUTY
CYCLE
40
50 60
70 80
100
Figure
4-2.
Duty
Cycle
Chart
Page
8

4-8.
VOLT-AMPERE
CURVE
(Figure
4.3)
The
volt-ampere
curve
shows
the
output
voltage
available
at
any
given
output
current
within
the limits
of
the
minimum
and
maximum
Voltage
Control
setting.
Load
voltage
is
pre
determined
to
a
large
degree
by
arc
characteristics.
With
the
use
of the
volt-ampere
curve,
it
IS
possible
to
determine
the
amperage
required
for
a
Specific
load
voltage.
With
reference
to
the
volt-ampere
curve
(Figure
4-3(,
the
curve
shows the
maximum
and
minimum
settings
of
the
Voltage
Control
only.
Curves of
other
settings
will
fall
between
the
maximum
and minimum
curves
Shown.
Figure
4-3.
Volt-Ampere
Curves
SECTION 5
-
SEQUENCE
OF
OPERATION
!
Never,
under
any
circumstances,
operate
the
welding
power
source
with
any
portion
of
the
outer
enclosure
removed.
In
addition
to
a
safety
hazard,
improper
cooling
may
result
in
damage
to
the
welding
trans
former
and
the
welding
power
source
components.
Warranty
is
void
if
the
welding
power
source
is
opera.
ted
with
any
portion
of the
outer
enclosure
removed.
10. Place the
POWER
Switch
in
the
ON
position.
!
Prior
to
welding,
it
is
imperative
that
proper
protective
clothing
(welding
coat
and
gloves)
and
eye
protection
(glasses
and/or
welding
helmet)
be
put
on.
Failure
to
comply may
result in
serious
and
even
permanent
bodily
damage.
5.1.
GAS METAL-ARC
(MIG) WELDING
1.
Make
electrical
input
connections
as
outlined
in
item
3-2.
2.
Make
secondary
connections
as
outlined
in
item
3-3.
3.
Contactor Control
connections
are
to
be
made
to
the
control/feeder
as
outlined
in
item
3-5,
4.
If 115
volts
ac
is
required
to
operate
a
Wire
Feeder,
see
item
3-4.
5. Make
shielding
gas
connections
as
required.
6.
Connect
the
work
clamp
to
the
work.
7.
Place
the
Range
Switch
in
the desired
position.
8.
Rotate
the
Voltage
Control
until
the
desired
voltage
is
indicated
on
the
OPEN-CIRCUIT VOLTS
Indicator.
9.
Make
all
necessary
adjustments
on
the
Wire Feeder.
11.
Commence
welding.
The
Voltage
Control
may
be
adjusted
while
welding.
5-2. SHUTTING
DOWN
1.
Break
the
arc
and
allow
the
welding
power
source to
idle
for
3
minutes
with
no
load
applied.
2.
Turn
the
shielding
gas
supply
off.
3.
Place
the
POWER
Switch
to
the
OFF
position.
1ur~iuIIrs]~ii.uJ
If
welding
is
performed
in
a
confined
area,
failure
to
turn
off the
shielding
gas
supply
could
result
in
a
build
up
of
shielding
gas
fumes,
thereby
endangering
per
sonnel
re-entering
the
welding
area.
SECTION
6-
MAINTENANCE
IMPORTANT
Be
sure
the
branch
circuit
or
main
disconnect
switch
is
open
or
electrical
input
circuit
fuses
are
removed
before
attempting
any
inspection
or
work
on
the
inside
of the
welding
power
source.
Placing
the
POWER
Switch
on
the
welding
power
source
in
the
OFF
position
does
not
remove
voltage
from
the
power
terminals
inside
of
the
welding
power
source.
6-1.
FAN
MOTOR
All
models
are
equipped
with
an
exhaust
fan and
rely
on
forced
draft
for
adequate
cooling.
The
fan
motor
is
manu
factured
with
lifetime
lubricated
sealed
ball
bearings
and
no
attention
should
be
required.
6-2.
TRANSFORMER
Occadonal
blowing
out of
the
dust
and
dirt
from around
the
transformer
is
recommended.
This
should
be done
period.
ically
depending
upon
the
location
of
the unit and
the
0
200 450 600
000 1000 1200 bOO
I
I
I
I
I
I
I
I
I
OM-238
Page
9

amount
of dust
and dirt
in
the
atmosphere.
The
welding
power
source outer
enclosure
should
be
removed
and
a
clean
dry
air
stream
should
be
used
for
this
cleaning
operation.
6-3. RECTIFIER
It
is
recommended that
the rectifier
be
cleaned
occasionally
by
blowing
it
out
with
compressed
air. This
cleaning
opera
tion
is
necessary
so
that
maximum
cooling
will
be
accom
plished
by
the
air
stream.
This should be
done
periodically.
depending
upon
the
location
of the
unit
and
the
amount
of
dust
and dirt
in
the
atmosphere.
It
will
be
necessary
to
remove
the
outer
enclosure for
this
cleaning
operation.
6-4.
CONTROL CIRCUIT
PROTECTION
The
entire control circuit of
the
welding power
source
is
protected
by
a
600
volts,
10
ampere,
cartridge
type
fuse
~F1).
This
fuse is
located
behind
the
rear
primary
access
panel,
immediately
to
the
upper
right.
Should
this fuse
open
the
welding
power
source
would
completely
shut
down.
I
I
IMPORTANT
U
If
it
should
become
necessary
to
replace
this
fuse
or
any
other
fuse
in
the
welding
power
source,
ensure
that
the
proper
size
fuse is
used
as
a
replacement.
.
SECTION
7
- TROUBLESHOOTING
The
data
collected
here,
discusses
some
of
the
common
problems
which
may
occur
in
this
welding
power
source.
The
assumption
of this
data
is
that
a
proper
welding
condition
has
been
achieved
and has
been
used
until
trouble
developed.
In
all
cases
of
equipment
malfunction,
the
manufacturers
recommendations should
be
strictly
adhered
to
and followed.
If after
performing
the
following
procedures
the
trouble
is
still
not
remedied,
it
is
recommended
that
a
serviceman be
called.
It
is
recommenc~d
that
the
circuit
diagram
be
used for
reference
during troubleshooting.
TROUBLE
PROBABLE
CAUSE
REMEDY
Li
mite
d
o
u
t
pu
t
and low
open.circuit voltage,
Operation
on
single
phase.
Open
line
fuse
on
one
phase.
Check
incoming
three-phase
power
for
correct
voltage.
Replace
fuse
if
open.
Input
voltage jumper
links
connected
to
wrong
terminals,
Connect
jumper
links
for
input
voltage
being
used. See
the
input
voltage
Label
on
the
rear
panel
hinged
door.
Fan
runs
slow.
~
Input
voltage
jumper
links
on
primary
con
nection
board
connected
for
incorrect
voltage.
Connect
jumper
links for
input
voltage
being
used.
See
the
input
voltage
Label
on
the
rear
panel
hinged
door.
Fan
does
not
run.
Weld
output
available.
Fan
motor
defective.
Check
fan
motor
leads
for
possible
short.
Check
fan motor
windings
for
continuity.
If
open,
replace
the
fan
motor.
Rotate
the fan
to
check
for
freedom
of
rotation. If
hard
to
rotate, replace
the
motor.
Fan
does
not
run
and
no
weld
output.
Fuse Fl
open.
Replace
fuse.
Line
fuses
open.
Replace
defective fuses.
Erratic
weld
current.
Incorrect
welding
cable
size. Use
proper
size
&
type
of
cable. See
item
3-3.
Loose
welding
cable
connections.
Tighten
all
welding
connections.
Incorrect drive
gear
for wire size
on
the
feeder.
See
wire
feeder
instruction
manual
troubleshooting
guide.
Page
10