Miller GA-40C is a heavy-duty welding gun designed for professional use with the Gas Metal-Arc Welding process. It offers precise control and efficient performance for various welding applications, handling wire diameters from .035 to 5/64 inches (0.9 to 2.0 mm). The gun's air-cooled design allows for continuous operation at a 60% duty cycle using C02 shielding gas. Experience enhanced productivity and reliability with the Miller GA-40C welding gun.
July
1985
FORM:
OM-1535
Effective
With
Style
No.
JA-21
MODEL
GA-40C
F11LE
COPY
RETURN
TO
FOLDER
OWNERS
MANUAL
MILLER
ELECTRIC
MFG.
Co.
718
S.
BOUNDS
ST,
P.O.
Box
1079
APPLETON,
WI
54912
USA
ADDITIONAL
COPY
PRICE
35
CENTS
NWSA
CODE
NO.
4579
PRINTED
IN
U.S.A.
IMPORTANT
Read
and
understand
the
entire
contents
of
both
this
manual
and
the
power
source
manual
used
with
this
unit,
with
special
emphasis
on
the
safety
material
throughout
both
manuals,
before
installing,
operating,
or
maintaining
this
equipment.
This
unit
and
these
instructions
are
for
use
only
by
persons
trained
and
experienced
in
the
safe
operation
of
welding
equipment.
Do
not
allow
untrained
persons
to
install,
operate,
or
maintain
this
unit.
Contact
your
distributor
if
you
do
not
fully
understand
these
instructions.
LIMITED
WARRANTY
EFFECTIVE:
FEBRUARY
25.
1985
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
condi-
In
the
case
of
Millers
breach
of
warranty
or
any
other
duty
tions
hereof,
Miller Electric
Mfg.
Co.,
Appleton,
Wisconsin
with
respect
to
the
quality
of
any
goods,
the
exclusive
remedies
4
warrants
to
its
Distributor/Dealer
that
all
new
and unused
therefore
shall
be,
at
Millers
option
(1)
repair
or
(2)
replacement
Equipment
furnished
by
Miller
is
free
from
defect
in
workman-
or,
where
authorized
in
writing
by
Miller
in
appropriate
cases,
(3)
ship
and
material
as
of
the
time
and
place
of
delivery
by
Miller.
the
reasonable
cost
of
repair
or
replacement
at
an
authorized
No
warranty
is
made
by
Miller
with
respect
to
engines,
trade
Miller
service
station
or
(4)
payment
of
or
credit
for
the
purchase
accessories
or
other
items
manufactured
by
others.
Such
price
(less
reasonable
depreciation
based
upon
actual
use)
upon
engines,
trade
accessories
and
other
items
are
sold
subject
to
return
of
the
goods
at
Customers
risk
and
expense.
MILLERs
?
the
warranties
of
their
respective
manufacturers,
if
any
.
All
option
of
repair
or
replacement
will
be
F.O.B.,
Factory,
at
engines
are
warranted
by
their
manufacturer
for
one
year
from
Appleton,
Wisconsin,
or
F.O.B.,
at
a
MILLER
authorized
service
date
of
original
purchase,
except
Tecumseh
engines
which
facility,
therefore,
no
compensation
for
transportation
costs
of
have
a
two
year
warranty.
any
kind
will
be
allowed.
Upon
receipt
of
notice
of
apparent
defect
or
failure,
Miller
shall
instruct
the
claimant
on
the
warranty
Except
as
specified
below,
Millers
warranty
does
not
apply
claim
procedures
to
be
followed.
to
components
having
normal
useful
life
of
less
than
one
Ii)
year,
such
as
spot
welder
tips,
relay
and
contactor
points,
MILLERMATIC
parts
that
come
in
contact
with
the
welding
ANY
EXPRESS
WARRANTY
NOT
PROVIDED
HEREIN
AND
,j)
wire
including
nozzles
and
nozzle
insulators
where
failure
does
ANY
IMPLIED
WARRANTY,
GUARANTY
OR
REPRESENTA-
k~
r~
not
result
from
defect
in
workmanship
or
material.
TION
AS
TO
PERFORMANCE,
AND
ANY
REMEDY
FOR
BREACH
OF
CONTRACT
WHICH,
BUT
FOR
THIS
PROVISION,
Miller
shall
be
required
to
honor
warranty
claims
on
war-
MIGHT
ARISE
BY
IMPLICATION,
OPERATION
OF
LAW,
ranted
Equipment
in
the
event
of
failure
resulting
from
a
defect
CUSTOM
OF
TRADE
OR
COURSE
OF
DEALING,
INCLUDING
~,
~
within
the
following
periods
from
the
date
of
delivery
of
Equip-
ANY
IMPLIED
WARRANTY
OF
MERCHANTABILITY
OR
OF
~
ment
to
the
original
user:
FITNESS
FOR
PARTICULAR
PURPOSE,
WiTH
RESPECT
TO
ANY
AND
ALL
EQUIPMENT
FURNISHED
BY
MILLER
IS
EX
1:
~rn:I1dr:~n=errsr:~:r:nd
~
.~.
~
CLUDED
AND
DISCLAIMED
BY
MILLER.
3.
A~
welding
guns,
feeder/guns
and
plasma
torches...
90
days
EXCEPT
AS
EXPRESSLY
PROVIDED
BY
MILLER
IN
4.
All
other
Millermatic
Feeders
1
year
WRITING,
MILLER
PRODUCTS
ARE
INTENDED
FOR
5.
Replacement
or
repair
parts,
exclusive
of
labor..
60
days
ULTIMATE
PURCHASE
BY
COMMERCIAL/INDUSTRIAL
6.
Batteries
6
months
USERS
AND
FOR
OPERATION
BY
PERSONS
TRAINED
AND
EXPERIENCED
IN
THE
USE
AND
MAINTENANCE
OF
provided
that
Miller
is
notified
in
writing
within
thirty
(30)
days
WELDING
EQUIPMENT
AND
NOT
FOR
CONSUMERS
OR
of
the
date
of
such
failure.
CONSUMER
USE.
MILLERS
WARRANTIES
DO
NOT
EXTEND
~
MILLERS
WARRANTIES
ANY
CONSUMER.
EXTEND
SECTION
1
-
INTRODUCTION
Ampere
Rating
60%
Duty
Cycle
dcrp
Wire
.
Diameter
~
.035
thru
5/64
in.
(0.9
thru
2.0
mm)
Hard
Cable
And
Hose
Length
Cooling
Method
Weight
Net
Ship
400
Amperes
With
C02
10
ft.
(3
m)
Air
8-1/4
lbs.
(3.8
kg)
9-3/4
lbs.
(4.4
kg)
15
ft.
(4.6
m)
Air
11-3/4
lbs.
(5.3~
kg)
13-1/4
lbs.
(6
kg)
Figure
1
-
1.
Specifications
1
-
1.
GENERAL
INFORMATION
AND
SAFETY
A.
General
B.
Safety
G
-
Gun
A
-
Air
Cooled
40
-
Ampere
Rating:
400
Amperes
C
-
Curved
Head
Tube
SECTION
2
-
INSTALLATION
ELECTRIC
SHOCK
can
kill.
Do
not
touch
five
electrical
parts.
Disconnect
input
power
and
employ
lockout/tagging
procedures
before
instalfing
gun.
Lockout/tagging
procedures
consist
of
padlocking
line
disconnect
switch
in
open
position,
removing
fuses
from
fuse
box,
or
shutting
off
and
red-tagging
circuit
breaker
or
other
disconnecting
device.
2
-
1.
GUN/FEEDER
CONNECTOR
INSTALLA
TION
(Figure
4-1)
IMPORTANT
the
gun
assembly.
The
outlet
guide
is
provided
as
part
of
1.
Loosen
the
gun/feeder
connector
securing
knob
on
the
wire
drive
assembly.
IMPORTANT
_____________
The
outlet
guide
should
be
positioned
as
close
as
possible
to
the
drive
rolls
without
touching
them.
This
gives
the
wire
maximum
column
strength
thus
ellminating
waves.
2.
Insert
the
gun/feeder
connector
into
the
wire
drive
assembly.
CAUTION
IMPORTANT
Information
presented
in
this
manual,
and
on
various
labels,
tags,
and
plates
on
the
unit
pertains
to
equip
ment
design,
installation,
operation,
maintenance,
and
troubleshooting
which
should
be
read,
understood,
and
followed
for
the
safe
and
effective
use
of
this
equip
ment.
The
installation,
operation,
maintenance,
and
troubleshooting
of
arc
welding
equipment
require
prac
tices
and
procedures
which
ensure
personal
safety
and
the
safety
of
others.
Therefore,
this
equipment
is
to
be
installed,
operated,
and
maintained
only
by
qualified
persons
in
accordance
with
this
manual
and
all
ap
plicable
codes
such
as,
but
not
limited
to,
those
listed
at
the
end
of
Section
1
-
Safety
Rules
For
Operation
Of
Arc
Welding
Power
Source
in
the
welding
power
source
Owners
Manual.
Safety
instructions
specifically
pertaining
to
this
unit
ap
pear
throughout
this
manual
highlighted
by
the
signal
words
and
___________
which
identify
different
levels
of
hazard.
statements
include
installation,
operating,
and
maintenance
procedures
or
practices
which
if
not
carefully
followed
could
result
in
serious
personal
injury
or
loss
of
life.
___________
statements
include
installation,
operating,
and
maintenance
procedures
or
practices
which
if
not
carefully
followed
could
result
in
minor
personal
injury
or
damage
to
this
equipment.
A
third
signal
word,
______________,
highlights
instruc
tions
which
need
special
emphasis
to
obtain
the
most
efficient
operation
of
this
equipment.
1
-
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
will
be
furnished
by
the
manufacturer
on
re
quest
if
occasion
to
file
claim
arises.
When
requesting
information
concerning
this
equip
ment,
it
is
essential
that
Model
Description
and
Serial
(or
Style)
Numbers
of
the
equipment
be
supplied.
1
-
3.
DESCRIPTION
-
This
gun
is
specifically
for
use
with
the
Gas
Metal-Arc
Welding
process.
The
alpha
numeric
designation
refers
to
the
following:
WARNING
CAUTION
WARNING
WARNING
OM-1
535
Page
1
3.
Tighten
the
gun/feeder
connector
securing
knob.
2
-
2.
GUN
SWITCH
CONNECTION
(Figure
4-1)
-
Align
the
key
on
the
gun
switch
connector
with
the
keyway
on
the
Switch
Control
receptacle;
insert
the
connector
and
rotate
the
threaded
collar
clockwise.
2
-3.
REPOSITIONING
GUN
SWITCH
(Figure
4-1)
-
The
gun
is
shipped
with
the
gun
switch
position
ed
as
illustrated
in
Figure
4-1.
The
gun
switch
can
be
repositioned
on
top
of
the
gun
handle
by
following
the
procedure
outlined
in
Steps
1-9.
1.
Loosen
head
tube
setscrew
in
gun
handle.
2.
Remove
liner
setscrew.
3.
Remove
pin
and
locking
ring
holding
handle
halves
together.
4.
Separate
two
halves
of
gun
handle.
5.
Rotate
head
tube
1800.
Ensure
that
machined
depressions
in
head
tube
are
lined
up
with
hole
for
setscrew
and
gun
cavities.
ii~i~iit~i~
Ensure
that
the
switch
leads
do
not
become
twisted
when
the
head
tube
is
rotated.
6.
Replace
liner
setscrew
in
opposite
side
of
handle.
7.
Join
handle
halves
together
and
rotate
locking
ring.
8.
Insert
pin
through
handle
halves
and
switch
lever.
Ensure
that
switch
spring
is
properly
posi
tioned
in
handle.
9.
Tighten
head
tube
setscrew.
SECTION
3
-
SEQUENCE
OF
OPERATION
3
-
1.
DUTY
CYCLE
-
The
duty
cycle
of
a
welding
gun
is
the
percentage
of
a
ten
minute
period
that
a
gun
can
be
operated
at
a
given
load.
This
gun
is
rated
at
60%
duty
cycle
using
C02
shielding
gas.
This
means
that
the
gun
can
be
operated
six
minutes
out
of
every
ten
with
the
CO2
gas
shielding.
The
remaining
four
minutes
the
gun
should
be
idle
to
permit
proper
cooling.
~
EXCEEDING
THE
RATED
AMPERAGE
WITH
CO2
OR
FAILING
TO
REDUCE
THE
WELDING
AMPERAGE
OR
DUTY
CYCLE
WHEN
USING
A
MIXED
SHIELDING
GAS
can
result
in
damage
to
the
gun.
Do
not
exceed
rated
amperage
when
using
CO2.
Operate
at
30%
duty
cycle
when
using
mixed
shielding
gases.
3
-2.
GAS
METAL-ARC
WELDING
1.
Ensure
that
proper
electrical
connections
have
been
made
to
the
welding
power
source
and
the
wire
feeder.
ELECTRIC
SHOCK
can
kill.
WELDING
WIRE
can
cause
puncture
wounds.
Do
not
touch
five
electrical
parts.
Do
not
point
gun
toward
any
part
of
the
body,
or
other
personnel,
or
any
conducting
surface
when
threading
welding
wire.
The
welding
wire
and
all
metal
parts
in
contact
with
it
are
energized
when
gun
trigger
is
depressed.
IMPORTANT
______________
When
installing
new
equipment,
or
after
prolonged
shutdown,
allow
shielding
gas
to
flow
continuously
for
at
least
one
minute
prior
to
welding
to
purge
the
shielding
gas
line.
To
avoid
wasting
wire
while
purging,
loosen
pressure
adjustment
knob
on
drive
assembly,
and
pivot
free
from
cover.
8.
Press
Purge
button
on
the
wire
feeder
(if
ap
plicable)
or
the
gun
switch
to
purge
the
gas
line.
9.
Close
drive
roll
cover
and
adjust
tension
(see
ap
propriate
Owners
Manual).
2.
Ensure
that
the
proper
shielding
gas
is
connected
to
the
shielding
gas
valve.
3.
Ensure
that
the
welding
wire
has
been
properly
threaded
and
that
correct
initial
tensions
have
been
set
on
the
drive
rolls
(refer
to
the
ap
propriate
Owners
Manual).
4.
Turn
on
the
shielding
gas
supply.
5.
Place
the
wire
feed
control(s)
in
the
required
position
for
the
welding
setup.
6.
Place
the
controls
on
the
welding
power
source,
in
the
required
position
for
the
welding
setup
(refer
to
welding
power
source
Owners
Manual).
7.
Energize
the
welding
power
source
and
the
wire
feeder
(refer
to
the
respective
Owners
Manuals).
10.
Actuate
the
gun
switch
to
run
the
wire
out
beyond
the
end
of
the
gas
nozzle.
Cut
the
wire
off
so
it
sticks
out
approximately
1/4
to
3/8
in.
(6.4
to
9.5
mm)
from
the
nozzle.
11.
Set
the
Wire
Speed
control
slightly
in
excess
of
anticipated
wire
speed.
WARNING
_________
ARC
RAYS,
SPARKS,
AND
HOT
SURFACES
can
burn
eyes
and
skin;
NOISE
can
damage
hearing.
Wear
correct
eye,
ear,
and
body
protection.
FUMES
AND
GASES
can
seriously
harm
your
health.
Use
enough
ventilation
to
keep
fumes
and
gases
from
the
breathing
zone.
See
Section
1
-
Safety
Rules
For
Operation
Of
Arc
Welding
Power
Source
in
welding
power
source
Owners
Manual
for
basic
welding
safety
information.
OM-1
535
Page
2
ELECTRIC
SHOCK
can
kill.
Do
not
touch
live
electrical
parts.
Do
not
touch
welding
wire
or
any
metal
part
in
contact
with
it
while
welding.
Welding
wire
and
all
metal
parts
in
contact
with
it
carry
weld
current
when
the
gun
switch
is
depressed.
12.
Hold
the
end
of
the
gas
nozzle
approximately
1/2
in.
(12.7
mm)
from
the
workpiece.
13.
Press
the
gun
switch.
Gas
will
start
to
flow,
wire
will
start
to
feed,
and
the
arc
will
be
established.
If
wire
slippage
is
noticed,
tighten
drive
roll
pressure
adjustment
1/4
turn
at
a
time
until
slip
page
stops.
Do
not
overtighten.
14.
After
the
controls
on
the
welding
power
source
and
the
wire
feeder
(if
applicable)
have
been
ad
justed
for
normal
operation,
welding
power
source
(and
wire
feeder)
will
function
automatically
whenever
the
gun
switch
is
depressed.
Releasing
the
switch
will
extinguish
the
arc
and
cause
wire
feed
and
gas
flow
to
stop.
3
-
3.
SHUTFING
DOWN
1.
Stop
welding.
2.
Turn
off
welding
power
source
and
wire
feeder.
3.
Turn
off
the
shielding
gas
at
the
source.
L~~U~E
HIGH
CONCENTRATION
OF
SHIELDING
GAS
can
harm
health
or
kill.
S
Shut
off
gas
supply
when
not
in
use.
SECTION
4
-
MAINTENANCE
4
-
1.
INSPECTION
AND
UPKEEP
-
Usage
and
shop
conditions
will
determine
frequency
and
type
of
maintenance
required.
1.
Inspect
gun
for
broken
areas,
cracks
and
loose
parts;
tighten,
repair
and
replace
as
required.
2.
Carefully
remove
any
weld
spatter
or
foreign
matter
which
may
accumulate
around
the
nozzle
orifice.
3.
Remove
any
accumulation
around
the
switch.
4.
Repair
or
replace
as
required
all
hose
and
cabl
ing;
give
particular
attention
to
frayed
and
crack
ed
insulation
and
areas
where
it
enters
equip
ment.
5.
Remove
grease
and
grime
from
components;
moisture
from
electrical
parts
and
cables.
CAUTION:
FLYING
DIRT
AND
METAL
PAR
TICLES
can
injure
personnel
and
damage
equip-
Point
gun
liner
only
in
a
safe
direction
away
from
personnel
and
equipment
when
cleaning
with
compressed
air.
6.
Blow
out
gun
casing
or
liner
with
compressed
air
whenever
the
wire
or
liner
is
removed.
4
-
2.
CONTACT
TUBE
REPLACEMENT
(Figure
4-1)
1.
Remove
nozzle.
2.
Cut
off
any
portion
of
the
electrode
wire
which
extends
beyond
end
of
contact
tube.
3.
Remove
contact
tube
and
replace
with
new
con-
tact
tube.
4.
Replace
nozzle
and
resume
operation.
4
-
3.
CHANGING
WIRE
SIZES
(Figure
4-1)
WARNING
_________
ELECTRIC
SHOCK
can
kill.
Do
not
touch
live
electrical
parts.
Shut
down
welding
power
source
and
disconnect
from
line
power
employing
lockout/tagging
pro
cedures
before
internally
inspecting
or
servicing.
Lockout/tagging
procedures
consist
of
padlocking
line
disconnect
switch
in
open
position,
removing
fuses
from
fuse
box,
or
shutting
off
and
red-tagging
circuit
breaker
or
other
disconnecting
device.
When
changing
the
gun
from
.035
or
.045
in.
(0.9
or
1.1
mm)
wire
to
1/16
or
5/64
in.
(1.6
or
2.0
mm)
wire
or
vice
versa,
it
is
necessary
to
change
the
contact
tube,
contact
tube
adapter,
liner,
and
wire
guides.
(For
inlel
wire
guide
installation,
refer
to
the
appropriate
welding
power
source
or
wire
feeder
Owners
Manual.)
1.
Remove
nozzle.
2.
Cut
off
any
portion
of
the
electrode
wire
which
extends
beyond
end
of
contact
tube.
3.
Remove
contact
tube.
4.
Retract
wire
onto
wire
spool
(see
wire
feeder
Owners
Manual).
5.
Disconnect
gun
assembly
from
wire
feeder.
6.
Remove
outlet
wire
guide.
7.
Loosen
liner
setscrew.
WARNING:
ELECTRIC
SHOCK
can
kill.
Do
not
touch
five
electrical
parts.
Disconnect
gun
from
wire
feeder
before
internally
inspecting
or
servicing.
HOT
SURFACES
can
cause
severe
burns.
Al/ow
cooling
period
before
servicing.
ment.
S
OM-1535
Page
3
8.
Remove
contact
tube
adapter
(if
applicable).
9.
Lay
cable
assembly
out
flat
and
straight
(no
coils
in
the
cable/conduit).
10.
Pull
out
liner
from
gun/feeder
connector
end
of
gun
assembly
(if
applicable).
________
FLYING
DIRT
AND
METAL
PAR
TICLES
can
injure
personnel
and
damage
equip
ment.
Point
gun
liner
only
in
a
safe
direction
away
from
personnel
and
equipment
when
cleaning
with
compressed
air.
11.
Blow
out
gun
casing
or
liner
with
compressed
air
whenever
the
wire
or
liner
is
removed.
12.
Loosen
collar
setscrew
and
remove
collar
and
0-ring
from
existing
liner
(if
applicable).
13.
Slide
the
0-ring
onto
the
end
of
sleeving
on
the
new
liner.
Position
collar
against
the
liner
sleev
ing
so
that
1-1/8
in.
(28.6
mm)
of
the
liner
pro
trudes
beyond
collar,
and
secure
collar
with
setscrew
(if
applicable).
Outlet
Wire
Guide
Collar
TC-044
406-A
CAUTION
CAUTION
14.
Insert
new
liner
into
gun/feeder
connector
end
of
gun
assembly
(if
applicable).
15.
Install
new
outlet
wire
guide.
16.
Cut
liner
off
so
it
sticks
out
1/4
in.
(6.4
mm)
from
the
end
of
the
head
tube
(if
applicable).
17.
Install
new
contact
tube
adapter.
18.
Install
new
contact
tube.
_________
OVERTIGHTENING
LINER
SETSCREW
will
damage
liner.
Do
not
overtighten
liner
setscrew.
19.
Tighten
liner
setscrew
in
gun
handle
to
lock
the
liner
in
place
(if
applicable).
20.
Replace
nozzle.
21.
Make
gun
connections
as
instructed
in
Sections
2-1
and
2-2.
22.
Thread
new
size
electrode
wire.
Head
Tube.
Nozzle
Contact
Tube
Contact
Tube
Adaptor
Leaf
Switch
Switch
Spring
Handle.
Bottom
Half
Handle.
Top
Half
Monocoil
Liner
Strain
Relief
0-Ring
Gun/Feeder
Connector
Figure
4
-
1.
Gun
Components
OM-1535
Page4
1.
Remove
nozzle.
2.
Cut
off
any
portion
of
the
electrode
wire
which
extends
beyond
end
of
contact
tube.
3.
Remove
contact
tube.
4.
Retract
wire
onto
wire
spool
(see
wire
feeder
Owners
Manual).
5.
Disconnect
gun
assembly
from
wire
feeder.
6.
Remove
outlet
wire
guide.
7.
Loosen
liner
setscrew.
8.
Remove
contact
tube
adapter.
9.
Lay
cable
assembly
out
flat
and
straight
(no
coils
in
the
cable/conduit).
10.
Pulloutthelinerfrom
gun/feeder
connector
end
of
gun
assembly.
FLYING
DIRT
AND
METAL
PAR-
CAUTION:
13.
With
switch
spring
properly
positioned
in
guii
handle
(see
Figure
4-1),
insert
pin
through
gun
handle
halves
and
gun
switch.
14.
Tighten
the
head
tube
setscrew.
OVERTIGHTENING
LINER
SETSCREW
will
damage
liner.
Do
not
overtighten
finer
setscrew.
15.
Replace
liner
setscrew
and
tighten.
16.
Replace
nozzle
locking
nut,
insulator,
contact
tube
adapter,
and
nozzle.
4
-
5.
INSTALLING
REPLACEMENT
LINER
(Figure
4-2)
_________
ELECTRIC
SHOCK
can
kill.
Do
not
touch
five
electrical
parts.
Disconnect
input
power
to
we/ding
power
source
and
employ
lockout/tagging
procedures
before
internally
inspecting
or
servicing.
Lockout/tagging
procedures
consist
of
padlocking
line
disconnect
switch
in
open
position,
removing
fuses
from
fuse
box,
or
shutting
off
and
red-tagging
circuit
breaker
or
other
disconnecting
device.
WARNING
L~~U~L
ELECTRIC
SHOCK
can
kill;
WELDING
WIRE
can
cause
puncture
wounds;
ENERGIZED
WELDING
WIRE
may
cause
arcing
when
touching
conductive
objects.
Do
not
touch
live
electrical
parts.
Do
not
point
gun
toward
any
part
of
the
body,
other
personnei.
or
any
conductive
surface
when
threading
welding
wire.
Use
cold
wire
JOG
button,
if
available,
to
thread
wire.
The
welding
wire
and
all
metal
parts
in
contact
with
it
are
energized
when
the
gun
switch
is
pressed.
23.
Resume
operation.
4
-
4.
CHANGING
THE
HEAD
TUBE
(Figure
4-1)
1.
Disconnect
gun
assembly
from
wire
feeder.
2.
Remove
the
nozzle,
contact
tube
adapter,
in
sulator,
and
nozzle
retaining
nut
from
head
tube.
3.
Remove
liner
setscrew.
4.
Loosen
head
tube
setscrew.
5.
Remove
pin
and
locking
ring
holding
the
gun
handle
halves
together.
6.
Separate
the
gun
handle
halves.
7.
Remove
head
tube
from
cable
connector.
8.
Remove
acrylic
glass
tubing
from
head
tube.
9.
Install
acrylic
glass
tubing
on
new
head
tube.
10.
Install
new
head
tube
on
cable
connector.
______________
If
replacing
an
800
head
tube
with
a
600 head
tube
or
a
straight
head
tube,
cut
the
existing
liner
off
so
it
sticks
out
1/4
in.
(6.4
mm)
from
the
end
of
the
head
tube.
If
replacing
a
600
or
a
straight
head
tube
with
an
800
head
tube,
remove
the
outlet
wire
guide
from
the
gun/feeder
connector
and
remove
the
finer.
Prepare
and
install
the
finer
as
instructed
in
Section
4-3,
Steps
11-14.
Reinstall
the
outlet
wire
guide.
Cut
the
liner
off
so
it
sticks
out
1/4
in.
(6.4
mm)
from
the
end
of
the
head
tube.
11.
Position
cable/conduit
and
head
tube
in
bottom
half
of
gun
handle
with
acrylic
glass
tube
on
top
of
the
leaf
switch
and
the
cable
strain
relief
fitted
into
the
appropriate
groove.
______________
Ensure
that
the
leaf
switch
is
properly
positioned
in
bottom
haff
of
gun
handle
as
illustrated
in
Figure
4-1,
and
the
machined
depression
in
the
head
tube
is
lined
up
with hole
for
the
head
tube
setscrew.
12.
Join
the
gun
handle
halves
together
and
rotate
the
locking
ring.
IMPORTANT
IMPORTANT
CAUTION
TICLES
can
injure
personnel
and
damage
equip
ment.
Point
gun
liner
only
in
a
safe
direction
away
from
personnel
and
equipment
when
cleaning
with
compressed
air.
11.
Blow
Out
gun
casing
or
liner
with
compressed
air
whenever
the
wire
or
liner
is
removed.
12.
Loosen
collar
setscrew
and
remove
collar
anid
0-ring
from
the
existing
liner
if
applicable.
OM-1535
Fage5
13.
Slide
the
0-ring
onto
the
end
of
sleeving
on
the
new
liner.
Position
collar
against
the
liner
sleev
ing
so
that
1-1/8
in.
(28.6
mm)
of
the
liner
pro
trudes
beyond
collar,
and
secure
collar
with
setscrew
if
applicable.
14.
Insert
new
liner
into
the
gun/feeder
connector
end
of
the
gun
assembly.
15.
Install
appropriate
outlet
wire
guide.
CAUTION
________
OVERTIGHTENING
LINER
SETSCREW
will
damage
liner.
Do
not
overtighten
finer
setscrew.
16.
Tighten
liner
setscrew.
17.
Cut
liner
off
so
it
sticks
out
1/4
in.
(6.3
mm)
from
the
end
of
the
head
tube.
18.
Reinstall
appropriate
contact
tube
adapter,
con
tact
tube,
and
nozzle.
19.
Thread
welding
wire
and
resume
operation.
Liner
Setscrew
Outlet
Collar
~
Wire
0-Ring
~
~
Guide
Gun/Feeder
Connector
TC083
963
Nozzle
6~Contact
Tube
Tube
Adapter
Figure
4
-
2.
Liner
Replacement
OM-1535
Page6
PARTS
LIST
November
1984
FORM:
OM-1535
Effective
With
Style
No.
JA-21
1
37
Figure
A
-
Exploded
View
Of
GA-40C
Gun
TC-049
927-B
2
5
36
9
10
11
21
20
11
18
19
Includes
Items
~~
thru
30
fl-i
27
OM-l53SPagol
Figure
A
Exploded
View
Of
GA-40C
Gun
Description
Quantity
1
047
957
2
054
183
2
054
157
2
047
566
2
047
565
3
094
985
3
094 987
4
094986
5
047603
6
081
957
7
601
869
8
089
400
9
049 737
10
059294
11
049313
12
047867
13
049872
14
079878
15
079535
16
048834
17
604525
18
081
909
19
091
602
20
047 574
21
079 974
22
047
555
22
047 556
23
049312
24
081
959
25
049
876
26
047
564
27
t083
891
28
079
975
29
049
307
30
081
959
27
t083
897
28
079
975
29
047
557
30
081
959
31
049
298
32
047
572
32
047
573
33
059
293
34
602173
35
047
575
36
049 854
37
046115
NOZZLE,
screw
type
1/2
orifice
x
2-3/4
NOZZLE,
screw
type
13/16
orifice
x
2-3/4
NOZZLE,
spot
-
flat
1-1/16
ID
x
3-19/32
NOZZLE,
spot
-
inside
corner
1-1/16
ID
x
3-19/32
2
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
4
1
2ft
2
1
1
2
1
1
3
2
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
Item
No.
Part
No.
NOZZLE,
screw
type
5/8
orifice
x
2-3/4
TUBE,
contact
.035
wire
TUBE,
contact
.045
wire
TUBE,
contact
1/16
wire
TUBE,
contact
5/64
wire
ADAPTER,
tube
-
contact
.035-.045
wire
ADAPTER,
tube
-
contact
1/16-5/64
wire
INSULATOR,
nozzle
NOZZLE,
retaining
nut
SWITCH,
leaf
NUT,
hex
-jam
5/16-18
HANDLE,
gun
SCREW,
set
-
socket
hd
5
/16-18
SPRING,
0.21
ODx5/8
long
TRIGGER,
gun
TUBING,
glass
acrylic
No.
9
x
1/2
CORD,
power
(consisting
of)
HOUSING
PLUG
&
PINS
(consisting
of)
TERMINAL,
male
CLAMP,
cable
CORD,
No.
182/c
(orderbyft)
SPLICE,
parallel
20-16
wire
STRAIN
RELIEF
CONNECTOR,
cable
-
feeder
end
0-RING,
1/2
lDxO.103
GUIDE,
wire
-
outlet
.045
wire
GUIDE,
wire
-
outlet
1/16-5/64
wire
RING,
locking
SCREW,
set
hollow
lock
6-32
x
3/32
NUT,
connecting
-
cable
FITTING,
hose
-
gas
LINER,
monocoil
.045
wire
(consisting
of)
.O-RING,3/l6IDxO.103
COLLAR,
locking
SCREW,
set
hollow
lock
6-32
x
3/32
LINER,
monocoil
.0-RING,3/l6IDxO.103
COLLAR,
locking
SCREW,
set
hollow
lock
6/32
x
3/32
STRAIN
RELIEF,
extension
CABLE/CONDUIT,
10
ftor
CABLE/CONDUIT,
l5ft
RIVET,
solid
-
flared
hd
7/32
dia
x
1-1/4
long
SCREW,
set
-
socket
hd
10-32
x
1/4
CONNECTOR,
cable
-
gun
end
TUBING,
glass
-
acrylic
1/2
x
1-1/4
TUBE,
head6O
Optional
Equipment
047
959
045
638
046
776
046
775
OM-1
535
Page
2
Item
Part
No.
No.
Description
Quantity
Figure
A
Exploded
View
Of
GA-40C
Gun
(Contd.)
046
774
NOZZLE,
spot
-
outside
corner
1-1
/
16
ID
x
3-19/32
071
019
TUBE,
head
45
degree
072
819
TUBE,
head
45
degree
044 005
NOZZLE,
spot
-
fIat
1-1/2
ID
x
3.593
054
202
TUBE,
contact
.030-.035
wire
1-5/16
054
201
TUBE,
contact
.045
wire
1-5/16
047
576
TUBE,
contact
1/16
wire
x
1-7/16
047
577
TUBE,
contact
5/64
wire
1-7/16
044
006
TUBE,
contact
.052
wire
1-5/16
057
730
TUBE,
contact
.052
wire
1-7/16
046
001
TUBE,
head
80
046
002
TUBE,
head
straight
180
045
887
HEAT
SHIELD/HANGING
BRACKET
tFor
all
gun
lengths.
BE
SURE
TO
PROVIDE
MODEL
AND
STYLE
NUMBERS
WHEN
ORDERING
REPLACEMENT
PARTS.
OM-1535
Page
3