Miller A-500 User manual

March 1979
FORM:
OM-233
Effective With
Serial No. HK243705
MODEL
A-500
OWNERS
MANUAL
fullER
MILLER
ELECTRIC
MFG.
CO.
718
S.
BOUNDS
ST.
P.O.
Box 1079
APPLETON
WI
54912
USA
ADDITIONAL COPY
PRICE
55
CENTS
NWSA
CODE
NO.
4579
PRINTED
IN
USA.

~.
/
LIMITED
WARRANTY
EFFECTIVE:
JANUARY
I,
1979
This
warranty supersedes
all
previous
MILLER
warranties
and
is
ex
clusive
with
no
other
guarantees
or
warranties
expressed
or
implied.
LIMITED
WARRANTYSubject
to
the
terms
and
conditions
As
a
matter
of
general policy
only,
Miller
may
honor
claims
hereof,
Miller Electric
Mfg.
Co.,
Appleton,
Wisconsin
warrants to
submitted
by
the
original
user
within the
foregoing periods.
its
Distributor/Dealer
that
all
new
and unused
Equipment
furnished
by
Miller
is
free
from defect
in
workmanship
and material
as
of the
In the
case
of Millers
breach
of
warranty
or
any
other
duty
time
and
place
of
delivery by
Miller.
No
warranty
is
made
by
Miller
with
respect
to
the
quality
of
any
goods,
the exclusive remedies
therefor
shall
be,
at
Millers
option,
(1)
repair
or
(2)
replacement
or,
with
respect
to
engines,
trade
accessories
or
other
items
manu-
where authorized
in
writing
by
Miller
in
appropriate
cases,
(3)
the
factured
by
others.
Such
engines,
trade
accessories
and other
items
are
sold
subject
to
the
warranties
of
their
respective
manu-
reasonable
cost
of
repair
or
replacement
at
an
authorized Miller
ser
facturers,
if
any.
At
the
present
time,
the
manufacturers
warranty
on
vice
station
or
(4)
payment
of
or
credit for the
purchase
price
(less
the
Mag-Diesel
engine
on
DEL-200
is
limited
to
six
months and
on
reasonable
depreciation
based
upon
actual
use)
upon
return
of the
all
other
engines
to
one
year.
goods
at Customers
risk and
expense.
Upon
receipt
of
notice
of
apparent
defect
or
failure,
Miller
shall
instruct
the
claimant
on
the
d
Except
as
specified
below,
Millers
warranty
does
not
apply
to
warranty
claim
procedures
to
be
followe
.
components having
normal useful life
of
less than
one
(I)
year,
such
ANY EXPRESS
WARRANTY NOT
PROVIDED
HEREIN AND
as
spot
welder
tips,
relay
and
contactor
points,
MILLERMATIC
parts
ANY IMPLIED
WARRANTY
GUARANTY OR REPRESENTA
that
come
in
contact
with the
welding
wire
including
nozzles
and
lION
AS
TO
PERFORMANCE,
AND ANY
REMEDY FOR
nozzle insulators
where
failure
does
not
result
from
defect
in
BREACH
OF
CONTRACT
WHICH,
BUT
FOR THIS
PROVISION,
~
workmanship
or
material.
MIGHT
ARISE
BY
IMPLICATION,
OPERATION
OF
LAW,
CUS
TOM
OF TRADE
OR
COURSE OF DEALING
INCLUDING
ANY
Miller
shall
be
required
to
honor
warranty
claims
on
warranted
IMPLIED
WARRANTY
OF MERCHANTABILITY
OR
OF FITNESS
Equipment
in
the
event of failure
resulting
from
a
defect within the
FOR
PARTICULAR
PURPOSE,
WITH
RESPECT
TO ANY AND
following
periods
from
the
date of
delivery
of
Equipment
to
the
ALL
EQUIPMENT
FURNISHED BY
MILLER
IS
EXCLUDED
original
user:
AND
DISCLAIMED
BY
MILLER.
I. Arc
welders,
power
sources
and
components
. .
. .
1
year
EXCEPT
AS EXPRESSLY
PROVIDED BY
MILLER
IN
WRIT-
(labor.
I
year
only)
PURCHASE
BY
COMMERCIAL/INDUSTRIAL
USERS AND
FOR
2.
Original
main
power
rectifiers 3
years
ING
MILLER
PRODUCTS
ARE
INTENDED
FOR ULTIMATE
3. All
welding
guns
and
feeder/guns
90
days
OPERATION
BY PERSONS
TRAINED AND
EXPERIENCED IN
4.
All
other
Millermatic
Feeders
1
year
THE
USE AND
MAINTENANCE
OF
WELDING
EQUIPMENT
AND
5.
Replacement
or
repair
parts,
exclusive
of labor
. .
60
days
NOT FOR
CONSUMERS
OR
CONSUMER
USE.
MILLER
WAR
6.
Batteries
.
6 months
RANTIES
DO
NOT
EXTEND
TO,
AND
NO
RESELLER IS
provided
that Miller
is
notified
in
writing
within
thi;ty(30)
days
of
AUTHORIZED TO
EXTEND
MILLERS WARRANTIES
TO,
the
date
of such failure
ANY
CONSUMER.
5,
5,
b...5,
j
-
.
- -

Section No.
Page
No.
SECTION
1

SAFETY RULES FOR OPERATION OF ARC
WELDING
POWER
SOURCE
1
-1.
Introduction
1
1
-
2. General
Precautions
1
1
-
3.
Arc
Welding
3
1
-
4.
Standards
Booklet
Index
4
SECTION
2
INTRODUCTION
2-1. General
5
2
-
2.
Receiving
-
Handling
5
2
-
3.
Description
5
2-4.
Safety
5
SECTION
3

INSTALLATION
3-1.
Location
5
3
-
2.
Electrical
Input
Connections
6
3
-
3.
Weld
Output
Connections
6
3
-
4.
Open
Circuit
Voltage
Selection
7
3. 5.
Contactor
Control
Receptacle
7
3
-
6.
Water Connections
7
3
-
7.
Wire
Feeder Shutdown Control
7
3
-
8.
1
15
Volts
AC
Receptacle
8
3
-
9.
Overload Protection 8
3-10.
Duty Cycle
8
3-11.
Volt-Ampere
Curve
8
SECTION
4
SEQUENCE OF OPERATION
4
-
1.
Gas
Metal-Arc
Welding
8
4
-
2.
Shutting
Down
8
SECTION
5
TROUBLESHOOTING
PARTS LIST

SECTION
1-SAFETY
RULES
FOR
OPERATION
OF
ARC
WELDING
POWER
SOURCE
1-1.
INTRODUCTION
1-2.
A.
We
learn
by experience.
Learning safety
through
personal
experience,
like
a
child
touching
a
hot
Stove
is
harmful,
wasteful,
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
reason
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.
These
safe
practices
are
divided
into
two
Sections:
1
General
Precautions,
common
to
arc
welding
and
cutting;
and
2
-
Arc
Welding
(and
Cutting)(only).
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 this
manual.
ANSI Z49.1 is
the
most
complete.
The
National Electrical
Code.
Occupational
Safety
and
Health
Administration,
local industrial
codes,
and local
in
spection requirements
also
provide
a
basis
for
equipment
in
stallation,
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.2.
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
bypersons
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
Z49.1
listed
1
in
Standards
index.
NEVER
ventilate
with
oxygen.
Lead
-,
cadmium
-,
zinc
-,
mercury
-,
and
beryllium
-
bearing
and
similar
materials,
when
welded
(or
cut)
may
produce
harmful
concentrations
of
toxic
fumes.
Adequate
local
exhaust ventilation
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
to
prevent
possible
accumulation
of
gases
in
the
space
if
down
stream
valves have
been
accidently
opened
or
left
open.
Check
to
be
sure
that
the
space
is
safe
before
re-entering
it.
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
con
taiiiing
even
minute
amounts
of trich
loroethylene
or
perchloroethylene.
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
cannot
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
Iconcealed
or
visible)
in
floors
or
walls
within
35
feet
may expose
combustibles
to
sparks
d.
combustibles
adjacent
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.
OM-233
Page
1

This
includes:
a
thorough
steam
or
caustic
cleaning
(or
a
solvent
or
water
washing,
depending
on
the
combustibles
solubility(
followed
by
purging
and
inerting
with
nitrogen
or
carbon
dioxide,
and
using
protective
equipment
as recom
mended
in
AGO.
Waterfilling
just
below
working
level
may
substitute for
inerting.
A
container
with
unknown
content
should be cleaned
(see
paragraph
above(.
Do NOT
depend
on sense
of
smell
or
sight
to
determine
if
it is
safe
to
weld
or
cut.
Hollow
castings
or
containers
must
be vented
before
welding
or
cutting.
They
can
explode,
Explosive
atmospheres.
Never
weld
or
cut
where
the air
may
contain flammable
dust,
gas,
or
liquid
vapors
(such
as
gaso
Iine(.
D.
Compressed
Gas
Equipment
Standard
precautions.
Comply
with
precautions
in
this
manual,
and those detailed
in
CGA
Standard
P-i,
PRECAU
TIONS FOR
SAFE
HANDLING OF COMPRESSED GASES
IN
CYLINDERS,
listed
6
in
Standards
index,
1.
Pressure
Regulators
Regulator
relief
valve
is
designed
to
protect
only
the
regula
tor
from
overpressure;
it is
not
intended
to
protect
any
downstream
equipment.
Provide
such
protection
with
one or
more
relief
devices,
Never
connect
a
regulator
to
a
cylinder
containing
gas
other
than
that
for
which
the
regulator
was
designed.
Remove
faulty
regulator
from
service
immediately
for
repair
(first
close
cylinder
valve(.
The
following
symptoms
indicate
a
faulty
regulator:
Leaks
-
if
gas
leaks
externally.
Excessive
Creep
-
if
delivery
pressure
continues
to
rise
with
downstream
valve
closed.
Faulty
Gauge
-
if
gauge
pointer
does
not
move
off
stop
pin
when
pressurized,
nor
returns
to
stop
pin
after
pressure
release
-
Repair.
Do
NOT
attempt
repair.
Send
faulty
regulators
for
repair
to
manufacturers
designated repair
center,
where
special techniques
and tools
are
used
by
trained
personnel.
2.
Cylinders
Cylinders
must
be handled
carefully
to
prevent
leaks
and
damage
to
their
walls,
valves,
or
safety
devices:
Avoid
electrical
circuit
contact
with
cylinders
including
third
rails,
electrical
wires,
or
welding
circuits.
They
can
produce
short
circuit
arcs
that
may
lead
to
a
serious
accident.
(See
i-3C.(
ICC
or
DOT
marking
must be
on
each
cylinder.
It
is
an
assurance
of
safety
when the
cylinder
is
properly
handled.
Identifying
gas
content
Use
only
cylinders
with
name
of
gas
marked
on
them;
do
not
rely
on
color
to
identify
gas
con
tent.
Notify
supplier
if
unmarked.
NEVER
DEFACE
or
alter
name,
number,
or
other
markings
on
a
cylinder.
It
is
illegal
and hazardous.
Empties:
Keep
valves
closed,
replace
caps
securely;
mark
MT;
keep
them
separate
from FULLS
and
return
promptly.
Prohibited
use.
Never
use
a
cylinder
or
its
contents
for other
than
its
intended
use,
NEVER
as
a
support
or
roller.
Locate
or secure
cylinders
so
they
cannot
be
knocked
over.
Passageways
and
work
areas.
Keep cylinders
clear of
areas
where
they
may
be
struck.
Transporting
cylinders.
With
a
crane,
use a secure
support
such
as
a
platform
or
cradle. Do
NOT
lift
cylinders
off the
ground
by
their
valves
or
caps,
or
by
chains,
slings,
or
mag
nets.
Do
NOT
expose
cylinders
to
excessive
heat,
sparks,
slag,
and
flame,
etc.
that
may
cause
rupture.
Do
not allow
contents
to
exceed
i30F.
Cool
with
water
spray
where
such
exposure
exists.
Protect
cylinders
particularly
valves
from
bumps,
falls,
falling
objects,
and weather.
Replace
caps
securely
when
moving
cylinders.
Stuck
valve.
Do
NOT
use a
hammer
or
wrench to
open
a
cylinder
valve
that
can
not be
opened
by
hand.
Notify
your
supplier.
Mixing
gases.
Never
try
to
mix
any
gases
in
a
cylinder.
Never refill
any
cylinder.
Cylinder
fittin~
should
never
be
modified
or
exchanged.
3. Hose
Prohibited
use.
Never
use
hose
other
than
that
designed
for
the
specified
gas.
A
general
hose identification rule
is: red
for
fuel
gas,
green
for
oxygen,
and black for inert
gases.
Use
ferrules
or
clamps designed
for
the
hose
(not
ordinary
wire
or
other
substitute(
as
a
binding
to connect
hoses
to
fittings.
No
copper
tubing
splices.
Use
only
standard
brass
fittings
to
splice
hose.
Avoid
long
runs
to
prevent
kinks
and abuse.
Suspend
hose
off
ground
to
keep
it
from
being
run
over, stepped on,
or
other
wise
damaged.
Coil
excess
hose
to
prevent
kinks
and
tangles.
Protect
hose
from
damage
by
sharp
edges,
and
by
sparks,
slag,
and
open
flame.
Examine
hose
regularly
for
leaks,
wear,
and loose
connec
tions.
Immerse
pressured
hose
in
water;
bubbles indicate
leaks.
Repair
leaky
or worn
hose
by
cutting
area
out
and
splicing
(i-2D3(.
Do NOT
use
tape.
4.
Proper
Connections
Clean
cylinder
valve
outlet
of
impurities
that
may.
clog
orifices
and
damage
seats
before
connecting regulator.
Except
for
hydrogen,
crack valve
momentarily,
pointing
outlet
away
from
people
and
sources
of
ignition. Wipe
with
a
clean lint-
less
cloth.
Match
regulator
to
cylinder.
Before
connecting,
check that
the
regulator
label and
cylinder
marking
agree,
and that the
regulator
inlet
and
cylinder
outlet
match.
NEVER CON
NECT
a
regulator
designed
for
a
particular
gas
or
gases
to
a
cylindercontaining
any
other
gas.
Tighten
connections.
When
assembling
threaded
connections,
clean and
smooth
seats
where
necessary.
Tighten.
If
connec
tion
leaks, disassemble,
clean,
and
retighten
using
properly
fitting
wrench.
Adapters.
Use
a
CGA
adapter
(available
from
your
supplier(
between
cylinder
and
regulator,
if
one
is
required.
Use
two
wrenches
to
tighten
adapter
marked
RIGHT
and
LEFT
HAND
threads.
Regulator
outlet
(or
hose(
connections
may
be
identified
by
right
hand
threads
for
oxygen
and
left
hand threads
(with
grooved
hex
on
nut
or
shank(
for fuel
gas.
5.
Pressurizing
Steps:
Drain
regulator
of residual
gas
through
suitable
vent
before
opening
cylinder
(or
manifold
valve)
by turning
adjusting
screw
in
(clockwise(.
Draining
prevents
excessive
compression
heat
at
high
pressure
seat
by allowing
seat to
open
on
pressur
ization.
Leave
adjusting
screw
engaged
slightly
on
single-stage
regulators.
Stand
to
side
of
regulator
while
opening
cylinder
valve.
Open
cylinder
valve
slowly
so
that
regulator
pressure
in
creases
slowly.
When
gauge
is
pressurized
(gauge
reaches
regu
lator
maximum( leave
cylinder
valve in
following
position:
For
oxygen,
and inert
gases, open
fully
to
seal
stem
against
possible
leak. For
fuel
gas, open
to
less than
one
turn
to
permit
quick
emer~ency
shutoff.
Page
2

ERRATA
SHEET
After this manual
was
printed,
refinements
in
equipmentdesign
occurred.
This
sheet
lists exceotions
to
data
appearing
later
in
this
manual.
AMENDMENT
TO
SECTION
5
-
TROUBLESHOOTING.
Figure
5-1.
Circuit
Diagram
Eftective
With
Serial
No.
HK282806
BE
SURE
TO PROVIDE
MODEL
AND
SERIAL NUMBERS
WHEN ORDERING REPLACEMENT
PARTS.
o
0
02T
2 37
33
o
39
038
0,33
032
031
o
17
0/6
0/4
0
13
11
OM-233
Page
A
Amend
Figure
5-1.
Circuit
Diagram
_______I~
CircuitDiagramNo.
B-048674-A
Item
Or
Dia.
Part
Replaced
Page
No.
Mkgs.
No. With
.
Description
Quantity
Pg
2
Q50,51
024
207 037 236
TRANSISTOR,
15
amp
100 volts
NPN
2
13
081 516
048560
PANEL,
rear
1
40 010
337
023365
WEDGE,3/16x1x4-i/2
9
68 SRi 035 224
083
971
RECTIFIER,
SCR/silicondiode(EffW/JB556978)
1
75

603
105
603
105
HOSE,
neoprene
No.1
5/161D(orderbyft)(qtychg)
1
ft
76 R1-3 030
026
Deleted
(EffW/JB556978)
78
Qi-3
039
526
083
936
THYRISTOR,
SCR 300
amp
300
volts
(EffW/JB556978)
(con

sisting
of)
3
Ri
-3
030
026
.
RESISTOR,
carbon 0.5
watt
560
ohm
1
Cl -6 031
689
CAPACITOR,
ceramic
0.01
uf
500
volts dc
(Eff
W/HK282806).
6
000
914
LINK,
connecting
6
12/8/81

Use
pressure
charts
(available
from
your
supplier)
for safe
and
efficient,
recommended
pressure
settings
on
regulators.
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
for
repair.
See User
Responsibility
statement
in
equip
ment
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
1-1,
1-2,
and
this
section.
Arc
Welding,
properly
done,
is
a
safe
process,
but
a
careless
opera
tor
invites
trouble.
The
equipment
carries
high
currents
at
significant
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,
and
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.
12
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
she
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
1-2B.
Generator
engine
exhaust
must
be
vented
so
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
so
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
for
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
so
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-233
Page
3

2.
Electrode
Holders
Fully
insulated
electrode
holders
should
be
used.
Do NOT
use
holders
with
protruding
screws.
3.
Connectors
Fully
insulated
lock.type
connectors
should
be used
to
join
welding
cable
lengths.
4.
Cables
Frequently
inspect
cables for
wear,
cracks and
damage.
IMMEDIATELY
REPLACE
those
with
excessively
worn
or
damaged
insulation
to
avoid
possibly
-
lethal shock from
bared
cable.
Cables
with
damaged
areas
may
be
taped
to
give
resistance
equivalent
to
original
cable.
Keep
cable
dry,
free
of oil
and
grease,
and
protected
from
hot metal
and
sparks.
5. Terminals
And
Other
Exposed
Parts
Terminals
and other
exposed
parts
of
electrical
units
should
have
insulating
covers
secured
before
operation.
6.
Electrode
Wire
Electrode
wire
becomes
electrically
HOT
when
the
power
switch
of
gas
metal-arc
welding
equipment
is
ON
and
welding
gun
trigger
is
pressed.
Keep
hands
and
body
clear of wire and
other
HOT
parts.
7.
Safety
Devices
Safety
devices
such
as
interlocks
and circuit breakers
should
not
be
disconnected
or
shunted
out.
Before
installation,
inspection,
or
service,
of
equipment,
shut
OFF
all
power
and
remove
line
fuses
(or
lock
or
red-tag
switches)
to
prevent
accidental
turning
ON
of
power.
Discon
nect
all
cables
from
welding
power
source,
and
pull
all 115
volts
line-cord
plugs.
Do
not
open
power
circuit
or
change
polarity
while
welding.
If,
in
an
emergency,
it must
be
disconnected,
guard
against
shock
burns,
or
flash from
switch
arcing.
Leaving
equipment
unattended.
Always
shut
OFF and
dis
connect
all
power
to
equipment.
Power disconnect switch
must
be
available
near
the
welding
power
source.
1-4.
STANDARDS
BOOKLET
INDEX
For
more
information,
refer
to
the
following
standards
or
their
latest
revisions and
comply
as
applicable:
1.
ANSI
Standard
Z49.i,
SAFETY IN
WELDING
AND
CUTTING
obtainable from
the
American
Welding
Society,
2501 NW
7th
St., Miami,
Fla.
33125.
2.
ANSI
Standard
Z87.i,
SAFE
PRACTICE
FOR
OCCUPA
TION AND
EDUCATIONAL
EYE
AND
FACE
PROTEC
TION,
obtainable
from
American
National
Standards
Institute.
1430
Broadway,
New
York,
N.Y.
10018.
3.
American
Welding
Society
Standard
A6.0,
WELDING
AND
CUTTING
CONTAINERS
WHICH
HAVE HELD
COMBUSTIBLES,
obtainable
same as
item
1.
4. NFPA
Standard
51,
OXYGEN-FUEL GAS
SYSTEMS
FOR
WELDING
AND
CUTTING,
obtainable
from
the
National
Fire Protection
Association,
470 Atlantic
Avenue, Boston,
Mass.
02210.
5,
NFPA
Standard
51B,
CUTTING AND
WELDING
PRO
CESSES,
obtainable
same
as
item 4.
6.
CGA
Pamphlet
P-i. SAFE
HANDLING
OF COM
PRESSED
GASES
IN
CYLINDERS,
obtainable
from the
Compressed
Gas
Association,
500
Fifth
Avenue,
New
York,
N.
Y.
10036.
7.
OSHA
Standard
29
CFR,
Part
1910,
Subpart
0,
WELD
ING,
CUTTING
AND
BRAZING.
Page
4

SECTION
2-
INTRODUCTION
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
water-cooled,
constant
potential
welding
power
source
which
produces
dc.
current.
This
welding
power
source
is
designed
to
be used
in
conjunction
with
the
Gas
Metal-Arc
Welding
(GMAW)
process.
This
unit
is
designed
to
be
operated
from
a
single
input
volt
age,
three-phase,
60
Hertz
power.
2-4.
SAFETY
Before
the
equipment
is
put
into
operation,
the
safety
sec
tion
at
the
front
of this manual should
be read
completely.
This
will
helpavoid
possible
injury
due
to
misuse
or
improper
welding applications.
The
following
definitions
apply
to
CAUTION, IMPORTANT,
and
NOTE
blocks found
throughout
this
manual:
th
is h
eading,
in
stallation,
operat
in
g,
and
ma
in
tenance
procedures
or
practices
will be found
that
if
not
carefully
followed
may
create
a
hazard
to
per
sonnel.
I
.
~.
.
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
mebt.
SECTION
3
-
INSTALLATION
3-1.
LOCATION
Figure
3-1.
Dimensional
Drawing
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.
The
installation
site
should
also
permit
easy
removal
of
the
welding
power
source
outer
enclosure
for maintenance
functions.
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.
H~ever,
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.
Open
Circuit
Voltage
Ranges
Rated
Welding
Current
100%
Duty
Cycle
input
At Rated
Load
Output
60
Hz.
Three-Phase

Amperes
At
230V
460V
480V
kva
kw
 
54
27
26 21.6
20.4
Dimensions
(Inches)
Weight
(Pounds)
Net
Ship


260
275
39.4
344
29.3
38.7 33.6 28.6
37.9
32.9
27.9
37.3 32.2 27.1
36.5
31.5 26.4
35.8 30.8
25.7
35.1
30.1
24.9
24.2
500
Amperes
@
35
Volts
Height
-
17-314
Width
-
19-1/2
Depth
-
18-1/4
Add
2-1/4
For
Lifting
Eye.
Figure
2-1.
Specifications
NOTE
Under this
heading,
explanatory
statements
will
be
found
that
need
special
emphasis
to obtain the
most
efficient
operation
of
the
equipment.
1-1/2
OM-233
Page
5

3-2.
ELECTRICAL
INPUT
CONNECTIONS
A.
Electrical
Input
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 the electrical
input
voltage
shown
on
the
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
rri

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.
I
I~_
r
Before
making
electrical
input
connections
to
the
welding
power
source, machinery
lockout
procedures
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
position.
If
the unit
is
connected
to
a
circuit
breaker,
or
other
disconnecting
device without
locking
facilities,
attach
a
red
tag
to
the device
to
warn
others

that
the
circuit
is
being
worked
on.
CAUTION
Connect
the
inpu:
conductors
to
th~ing
power
source
before
making
connections
to
the
three-phase

power
supply.
The
input
conductors
should be covered with
an
insulating
material
which
conforms
to
local electrical standards.
Table
3-1 is
provided
only
as
a
guide
for
selecting
the
proper
size
input
conductors
and
fuses.
Table 3-1.
Input
Conductor
And Fuse
Size
Input
Conductor
Size
-
AWG
Fuse
Size
In
Amperes
230V 460V 480V
230V
460V 480V
6(81
10(10)
10110)
90
45
45
Input
conductor
sizes
are
based
on
allowable
ampacities
of
insulated
copper
conductors,
having
a
temperature
rating
of
75C,
with
not
more
than three conductors
in
a
raceway
or
cable.
Numbers
in
I
I
are
equipment
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.
reco
mme
nded
th
at
a
ter
ml
na
I
lug
S
adeq
ua
te
amperage
capacity
be attached
to
the ends of
the
in
put
and
ground
conductors.
The
hole
diameter
in
the
terminal
lug
must be
of
proper
size
to accommodate
the line
and
ground
terminal
studs.
Connect
the
three
input
conductors
to
the line
terminals
on
the
primary
terminal
board and
connect
the
ground
conduc
tor
to the
ground
terminal
(see
Figure
3-2
for location
of
terminals).
The
remaining
end of the
ground
conductor
should
be
connected
to a
proper
ground,
Use
a
grounding
method that is
acceptable
to
the local
electrical
inspection
authority.
I
The
ground
terminal
is
connected
to
the
welding
power
source
chassis
and
is
for
grounding
purposes
only.
Do
not connect
a
conductor
from
the
ground
terminal
to
any
one
of
the
line terminals
as
this will
result
in
an
electrically
energized welding
power

source
chassis.
Figure
3-2.
Input
Conductor Connections
3.3. WE1..D OUTPUT CONNECTiONS
To
obtain the
full
rated
output
from this
unit,
it
is
necessary
to
select,
install,
and maintain
proper
welding
cables.
Failure
to
comply
in
any
of these
areas
may
result in less than
satisfactory
welding
performance.
L,
Ensure
that the
unit is
completely
shut
down before
making
any
weld
output
connections.
A.
Location
The
POSITIVE
and
NEGATIVE
weld
output
terminals
are
located
on
the
upper
portion
of
the
front
panel,
B.
Welding
Cables
If
welding
cables
were
not
ordered with this
unit,
the
steps
listed should
be
followed
to
ensure
the
best
welding
performance:
1.
It is
recommended that
the
welding
cables
be
kept
as
short as
possible,
be
placed
close
together,
and be of
adequate
current
carrying capacity.
The
resistance of the
welding
cables
and
connections
causes
a
voltage
drop
which is
added
to
the
voltage
of the
arc.
Excessive
cable
resistance
may
result
in
overloading
as
well
as
reducing
the
maximum
current
output capability
of this
unit.
Prdper
operation
is
to
a
great
extent
dependent
on
the
use
of
welding
cables
and
connections
that
are
in
good
condition
and of
adequate
size.
2.
Use Table 3-2
as a
guide
for
selecting
correct
cable size
for
the
anticipated
maximum weld
current
which
will
be
~,,
Table 3-2
shows total cable
length,
which
includes
the electr.4e
and work
cable.
Example:
If
the
electrode
holder
cable
is
75 feet
long
and the
work
cabte
25
feet
long,
select
the size
cable
that
is
recommended
for 100
feet
at
the
maximum
weld
current
that is
to
be
used.
3.
Do
not
use
damaged
or
frayed
cables.
4.
Use
correct
lugs
on
the
weld cables
to
connect
the
work
clamp
and
to connect
the cables
to
the weld
output
terminals.
5,
Ensure
that all
connections
are
clean
and
tight.
CAUTION
I
Ground
Terminal
TA-049 297
I
I
Page
6

~oo~ ~
38.7 VOLTS
0~0ofl
~
37.9 VOLTS
fl0o0~ fl~fl
373 VOLTS
fl0o0~ fl~fl
36,5
VOLTS
oo~oo~
35.8 VOLTS
oo~oo~
35.1
VOLTS

oo~oo~
0o~ofl
~
34.4
VOLTS
32.2 VOLTS
o~oo~o
31 5 VOLTS
oo~o~o
oo~o~o
29.3 VOLTS
28.6
VOLTS
~
~
27.9 VOLTS
27.1
VOLTS
~
0~fl0~
264 VOLTS
~
~
25.7
VOLTS
oo~oo
fl0~0o
24.9
VOLTS
Positive
Negative
Output
Terminal
Jr
~@fififi~
~0@~
~
~
39.4 VOLTS 33.6 VOLTS
fl0ofl
~
~a~o~o
32
9
VOLTS
oo~o~o
~ooo~o
oo~o~o
o~oo~o
o~o~oo
o~oo~o o~oo~o
30.8 VOLTS
o~oo~o
~ ~
303
VOLTS
o~ooo~
o~o~oo
o~oo~o
oo~oo
oo~oo
oo~oo
oo~oo
24.2 VOLTS
Table 3-2.
Welding
Cable Size
Figure
3-3.
DC
Open
Circuit
Voltage
Selection
SCR
Circuit
Power Pilot
Output
Fuse
Circuit
Breaker
Light
Terminal
~~-.--~
I I
B-049
271
WELDING
AMPERES
TOTA
L
LENGTH OF
CABLE
(COPPER
~N WELOCI
~CUiT
50
100 150
200
250 300
350 400
100
4
4
2
2
2
1
1/0
1/0
150
2 2
2
1
1/0
2/0 3/0 3/0
200
11
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
3/0
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
~a~a
O.oO.~
~
0
115
Voits
115
Volts
AC
Contactor
Receptacle
Receptacle
Controi
Fuse
Receptacle
TA-049
277
Figure
3-4. Front
Panel
3-6. WATER
CONNECTIONS
On
the
left
side
of
the
rear
panel
are
water
connections
labelled
WATER IN
and
WATER
OUT.
These
connections
are
female
type
and have
right-hand threading.
It
is
recom
mended
that the
water
pressure
be
set
between
40
and
60
psi.
A-u02
623
NOTE:
A. 50
FEET
OR LESS.
B. 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
(OCVI
OF
TI-tE
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. OPEN CIRCUIT
VOLTAGE
SELECTION
(Figure
3-3)
Behind
the
access
door
on
the
front
panel
is
an
18
tap
terminal
board.
This
terminal
board
provides
facilities
for
changing
the
dc
open
circuit
voltage.
Twenty-two
open
circuit
voltages
are
obtainable.
To
obtain
the
desired
open
circuit
voltage,
position
the
six
leads
connected
to
the
terminal
board
as
shown
in
Figure
3-3.
3- 5.
CONTACTOR CONTROL
RECEPTACLE
(Figure
3-4)
The
CONTACTOR CONTROL
receptacle
is
a
two
pole
twist-
lock
receptacle
that
provides
a
junction
point
for
a
Contactor
Control.
In
order
for
open
circuit
voltage
to
be
present,
115
volts
ac
must
be
applied
to
the
CONTACTOR CONTROL
receptacle.
To
suspend
weld
output,
115
volts
ac
must
be
removed
from
the
receptacle.
I
IMPORTANT
I
It
is
imperative
that
water
flow
through
the
Welding
1
power
source
is
not
interrupted
while
the unit
is in
use.
Failure
to
comply
may
result in
damage
to
the
main
rectifier
and.
transformer
if
the
thermostats

should
fail.
When
the
welding
power
source
is
shutdown,
it
is
recom
mended
that
water
flow be
stopped.
This will
prevent
water
condensation inside the
welding
power
source.
When
the
welding
power
source
is
being
moved
or
during
storage,
the
water
should be drained from
the unit
and
the
water
lines
purged
with
air
to
prevent
freezing
should
the
unit
be
exposed
to
freezing
temperatures.
3-7.
WIRE
FEEDER SHUTDOWN
CONTROL
A
set
of
normally-open
contacts
from
control
relay
CR2
are
connected
to
terminals
13
and
14
of
terminal
strip
iT.
This
set
of
contacts
is
intended to
be
wired
in series
with
one
of
OM-233
Page
7

the
wire
feeder
electrical
input
power
leads for the
purpose
of
shutting
the
wire
feeder
down
in
the
event
that
one
or
more
of
the thermostats
in
the
welding
power
source
should
open
and
shut
the
welding
power
source
down.
Failure
to
connect
the wire
feeder
to
the
contacts
of
CR2
would
result
in
the
wire
feeder
continuing
to
feed
wire
even
though
weld
current
is
not
present.
Make
the connections
to
the
welding
power
source
as
follows:
1.
Remove
the
right
side
panel.
Terminal
strip
iT
is located
in the
upper
rear
corner
of
the
right
side of
the
welding
power
source.
2.
Locate
the
7/8
hole
in the
rear
panel
of
the
welding
power
source
and
route
leads
from
the wire feeder
through
the
hole
to
terminal
striA
iT.
3. Connect
wire feeder
input
power
leads
to
terminals
13
and
14
of terminal
strip
iT.
4.
Replace
right
side
panel.
3-
8. 115
VOLTS
AC RECEPTACLE
(Figure
3-4)
The
three-pole,
twistlock
receptacle
on
the
front
panel
of
the
welding
power
source
is
intended
to
provide
115
volts,
60
Hertz
electrical
power
for
operation
of
accessory
equipment.
To
secure
the
corresponding
three-pole
plug
in this
recep
tacle,
insert the
plug
into
the
receptacle
and
rotate
the
plug
clockwise.
IMPORTANT
The 115
VOLTS AC
receptacle
is
protected
by
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
replacement.
A
fuse
of
a
larger
rating
will
permit
overloading
of
the
115
volts
circuitry
and
thereby
cause
damage
to
the

weldingpowersource.
3-9.
OVERLOAD
PROTECTION
The
SCR
circuitry
is
protected by
a
miniature
fuse Fl lo
cated
on
the
front
panel
of
the
welding
power
source
(see
Figure
3-4).
If
fuse Fl
should
open,
the
weld
output
would
cease.
There
are
thermostats
located
in the main
rectifier and
transformer.
In
the event water
flow
stops
while
the unit
is in
use
and
the
main rectifier
and/or
transformer becomes
too
warm,
the
thermostat(s)
will
open
and
suspend
all
output.
If
this
occurs,
initiate
water
flow
and allow
the
unit
a
cooling
period
before
attempting
to
resume
operation.
The
POWER
circuit
breaker
CR1
will
open
to
interrupt
in
coming
power
if
the
input
power
is
too
high.
The
circuit
breaker
must
be
manually
reset.
1.
Make
electrical
input
and weld
output
connections
as
outlined
in
Section
3-2
and
3-3.
2.
Make
water
connections
as
required
and
turn water
flow
on.
3.
Select desired dc
open
circuit
voltage
as
outlined in
Section
3-4.
4.
Make
connections
to
CONTACTOR CONTROL
recep
tacles.
5.
Place POWER
circuit
breaker
in
ON
position.
6.
Close
the
Contactor
Control
to
apply
115
volts
ac
to the
welding
power
source
voltage
control
circuit.
3-10. DUTY CYCLE
(Figure
3-5)
The
duty
cycle
of
a
welding
power
source
is
the
percentage
of
a
ten
minute
period
that
a
welding
power
source
can
safely
be
operated
at
a
given output.
This
welding
power
source
is
rated
at
100
percent duty
cycle.
This
means
that
the
welding
power
source can
be
safely
operated
at
rated load
con
tinuously.
Figure
3-5
enables
the
operator
to
determine
the
safe
output
of
the
welding
power
source
at various
duty
cycles.
800
3-11. VOLT-AMPERE CURVE
(Figure
3-6)
The
volt-ampere
curves,
Figure
3-6,
show the
output
voltage
available
at
each
given
output
current.
40

Prior
to
welding,
it
is
imperative
ti
t
proper
protective1
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.
7. Commence
welding.
4-2.
SHUTTING
DOWN
1.
Open
the
Contactor
Control
to
remove
115
volts
ac
from
the
welding
power
source
voltage
control
circuit.
2.
Allow
the
welding
power
source
to
idle
with
the
water
flowing
for
a
cooling period.
3.
Turn off
water
flow.
4.
Place
the
POWER
circuit
breaker
in
the
OFF
position.
w
UI
0.
4
a
z
0
UI
700
600
500
50
60
70
80
90
100
%
DUTY CYCLE
8-049
263
Figure
3-5.
Duty
Cycle
Chart
35
r
30
-1
0
20
0
4-1.
GAS
METAL-ARC WELDING
(GMAW)
SECTION
4
-
SEQUENCE
OF OPERATION
100 200 300
400
500
600
700
DC AMPERES
Figure
3-6.
Volt-Ampere
Curve
B-049
264
Page
8

SECTION
5
-
TROUBLESHOOTING
1IIUh1~1II~1
Hazardous
voltages
are
present
on
the
internal
circuitry
of
the
welding
power
source as
long
as
power
is
connected
to
the Unit.
Disconnect
power
before
attempting
any
inspection
or
work
on
the
inside
of
the
unit.
Troubleshooting
of internal
circuitry
should be
performed by qualified personnel only.
The
following
chart is
designed
to
diagnose
and
provide
remedies
for
some
of the troubles
that
may
develop
in this
welding
power
source.
It is
assumed
that
proper
installation
has
been
made,
according
to
Section
3
of
this
manual,
and
that the
welding
power
source
has
been
functioning
properly
until
this
trouble
developed.
Use
this
chart
in
conjunction
with the circuit
diagram
while
performing troubleshooting
procedures.
If
the
trouble
is
not
remedied
after
performing
these
procedures,
the
nearest
Factory
Authorized
Service Station
should be
contacted. In
all
cases
of
equipment
malfunction,
the
manufacturers
recommendations
should
be
strictly
followed.
1f
it
becomes
necessary
to
replace
any
fuse
in
the
welding
power
source,
ensure
that
a
fuse
of the
proper
size is used.
I
U
U
I
TROUBLE PROBABLE
CAUSE
REMEDY
No
weld
output.
POWER
circuit
breaker
open.
Manually
reset
POWER
circuit
breaker,
Fuse
Fl
open.
Replace
fuse
F1.
Thermostat(s)
open.
Allow
a
cooling
period
before
attempting
to
resume
opera
tion.
Control
relay
CR1
defective. Check
relay
CR1
and
replace
if
necessary.
Printed
circuit
board
not
secure
in
receptacle.
Ensure
that the
printed
circuit
board is
secure
in
receptacle.
Printed
circuit
board
defective.
Check
printed
circuit board and
replace
if
necessary.
Defective
component
in main
rec-
tifier
SRi.
Check
main
rectifier
SRi
components
and
replace
necessary
parts.
Limited
output
and
low
open-
Circuit
voltage,
DC
open-circuit voltage
selector
on
wrong
taps.
See
Section
3-4
for
proper open
-circuit
voltage
selection.
Open
line
fuse
on one
phase.
Check
input
line
fuse(s)
and
replace
as
necessary.
Printed
Circuit
board
not
secure
in
receptacle.
Ensure
that
the
printed
circuit
board
is
secure
in
receptacle.
Printed
circuit
board defective.
Check
printed
Circuit board and
replace
if
necessary.
Defective
component
in
main
rec-
tifier
SR
1.
Check
main
rectifier
SRi
components
and
replace
necessary
parts.
Erratic
weld
output.
Incorrect
welding
cable size.
Use
proper
size and
type
of
cable
(see
Section
3-3,
Table
3-2).
Loose
welding
cable
connections.
Ensure
all
connections
are
clean and
tight.
No 115
volts
ac
at
115 VOLTS
AC
duplex
receptacle.
Fuse F2
open.
Replace
fuse
F2.
OM-233
Page
9

Figure
5-1.
Circuit
Diagram
o o0
0 0
02T
36
22
35
21 37
23
039
038
033
032
031
017
016
014
073
IT
a
c~
Circuit
Diagram
No.
B-081
644
FIRING CIRCUIT
Page
10

March
1979
FORM:
OM-233
PARTS
LIST
Effective
With Serial
No.
HK243705
MODEL
A-500

C,,
I-
C.)
.2~
~
U..
0.
cc
U..
C,,.
IDe)
o,o~
I-
>.
.c
E
I
IL
ł~.
Co
cc,
I-
I-
IL.
CO
I-.
OM-233
Page
1

Item
Dia.
Factory
No.
Mkgs.
Part
No.
Description
Quantity
Figure
A
Main
Assembly
1
034 025
CIRCUIT
CARD
ASSEMBLY,
firing
-
circuit
(consisting
of)
1
C50
034
286
.
CAPACITOR,
poly
film
0.1
uf 100
volts
dc
1
C51 031 633
.
CAPACITOR,
electrolyte
80
uf 25
volts
do
1
C52
031
646
.
CAPACITOR,
ceramic
0.001
uf
1000
volts dc
1
050,51,52
026
202
.
DIODE,
rectifier
1
amp
400
volts
straight
polarity
3
Q50,51
024
207
-
TRANSISTOR,
15
amp
100
volts
2
R50 030 761
.
RESISTOR,
carbon
1
watt
10
ohm
1
R51
030
021
.
RESISTOR,
carbon
0.5
watt
4700
ohm
1
R52
030
038
.
RESISTOR,
carbon
0.5
watt
220
ohm
1
R53
030
004
.
RESISTOR,
carbon
0.5
watt
10K
ohm
1
R54,55,56
030
802
.
RESISTOR,
carbon
1
watt
22
ohm
3
SR5O
021
939
.RECTIFIER,
integrated
1.5
amp
400
volts
T50
032
304
.
TRANSFORMER,
inverter
2
032
979
ENCLOSURE,
printed
circuit board
3
RC3 039
756
CONNECTOR,
amphenol
1
4 Ti
081
551
TRANSFORMER,
power
-
main
(See
Fig.
B
Page
3)
5
010
323
CLAMP,
hose
1/4
-
5/8
dia
20
6
603 105
HOSE,
neoprene-
braid No.
1
x 5/16
ID
(order
by
ft)
9 ft.
7
081
410
ANGLE,
mounting
-
transformer
rear
8
081
512
PANEL,side
2
9
081
514
COVER,top
1
10
022
627
GASKET,
lifting-
eye
cover
ii
Figure
C
BAFFLE,with-components(SeePage4)
12
000
527
BLANK,
snap
-
in
7/8
1
13
081
516
PANEL,
rear
14
602 956
FITTING,
pipe
-
brass
adapter
bulkhead
1/4
NPT
x
15/16
2
15
604 308
FITTING,
brass
-
barbed
male
1/4
TBG
x
1/4
NPT 2
16
081
402
BASE
1
17
Figure
D
PANEL,
front
-
with
components
(See
Page
6)
18
081 420
TERMINAL
BOARD,
power
output
19 081 426
BRACKET,
mounting
-
transformer
& circuit
card
enclosure
20
081 422
STRIP,
insulating
terminal
-
secondary
BE
SURE TO PROVIDE MODEL
AND
SERIAL
NUMBER
WHEN
ORDERING
REPLACEMENT
PARTS.
OM-233
Page
2

Item
Dia.
No.
Mkgs.
31
TP3,4
32
33
34
35
36
37
38
39
40
026
181
605
538
**081
640
**081
639
**081
550
081
526
081 525
081
527
081
417
010
337
2
4
2
1
1
4
4
3
3
9
Factory
Part No.
Description
Quantity
Figure
B
081 551
Transformer,
Power
-
Main
(See
Fig.
A
Page
2
Item 4)
THERMOSTAT,
normally
closed
CABLE
TIE
COIL,
primary/secondary
COIL,
primary/secondary
w/1
15
-
24
volts
winding
TRANSFORMER
SUBASSEMBLY,
power
-
main
(consisting
of)
.STRIP,
mica
0.015x
3-1/2x3-1/2
STRIP,
polyester
glass
laminate
0.031
x
3-1/2
x
3-1/2
STRIP,
mica
0.015
x
2-5/8 x
3-3/8
HEAT
SINK,
coil
-
transformer
WEDGE,
polyester
glass
laminate
3/16
x
3/4
x
5
34
33
32
31
35
TD-049
520
Figure
B

Transformer,
Power-Main
**Replace
at
Factory
or
Factory
Authorized
Service
Station.
BE SURE
TO PROVIDE
MODEL
AND
SERIAL NUMBER WHEN ORDERING REPLACEMENT
PARTS.
Page
3