Miller GA-17C - Section 5 - Maintenance; Inspection and Upkeep; Contact Tube Replacement; Changing Wire Sizes and Replacing Liner

16.
After
the
controls on
the
welding
power
source
and
the
wire feeder
(if
applicable)
have
been
adjusted
for
normal
operation,
the
welding
power
source
(and
wire
feeder)
will
function
automatically
when
the
gun
trigger
is
pressed.
Releasing
the
gun
trigger
will
ex
tinguish
the
arc
and
cause
the
wire
feed and
gas
flow
to
stop.
4-2.
SHUTTING
DOWN
1.
Stop
welding.
2.
Turn off
welding
power
source
and
wire
feeder.
3. Turn
off the
shielding
gas
at
its
source.
5-1.
INSPECTION
AND
UPKEEP
Usage
and
shop
conditions
will
determine
frequency
and
type
of
maintenance
required.
a
WARNING:
ELECTRIC
SHOCK
can
kill;
WELDING
WIRE
can cause
puncture
wounds;
HOT SURFACES
can
cause
severe
burns.

Do
not
touch live
electrical
parts.

Shut
down
welding
power
source
and wire
feeder
before
working
on
gun.

Disconnect
gun
from wire
feeder before
in
specting,
maintaining,
or
servicing.

Allow
a
cooling period
before
servicing.
1.
Inspect
gun
for broken
areas,
cracks and loose
parts:
tighten,
repair
and
replace
as
required.
2.
Carefully
remove
any
weld
spatter
or
dirt
that has
accumulated
around nozzle
opening
and inside
nozzle.
3.
Repair
or
replace
as
required
all
hose
and
cables;
give
particular
attention
to
frayed
and
cracked
insu
lation and
areas
where
it
enters
equipment.
4.
Remove
grease
and
grime
from
components
and
moisture
from
electrical
parts
and cables.
5.
Blow
out
casing
with
compressed
airwhen
changing
wire.
This
removes
any
loose
metal
chips
and dirt
that
may
have
accumulated.
a
CAUTION:
FLYING
DIRT AND
METAL PARTI
CLES
can
Injure
personnel
and
damage
equIpment.

PoTht
gun
liner
only
in
a
safe
direction
away
from
personnel
and
equipment
when
cleaning
with
compressed
air.
5-2.
CONTACT
TUBE
REPLACEMENT
(Figure
3-1)
a
WARNING:
ELECTRIC
SHOCK
can
kill;
WELDING
WIRE
can
cause
puncture
wounds;
HOT
SURFACES
can
cause
severe
burns.

Do
not
touch
live
electrical
parts.

Shut
down
welding
power
source
and
wire
feeder
before
working
on
gun.

Disconnect
gun
from
wire
feeder before
in
specting,
maintaining,
or
servicing.

Allow
a
cooling period
before
servicing.
1.
Remove
nozzle.
A
slight
twist
clockwise aids
re
moval
and
installation.
2.
Cut off
any
portion
of
electrode wire
which
extends
beyond
end of
contact
tube.
3. Remove
contact
tube,
and
replace
with
new
contact
tube.
4.
Reinstall
nozzle,
and
resume
operation.
5-3.
CHANGING
WIRE
SIZES
AND
REPLACING
LINER
a
WARNING:
ELECTRIC
SHOCK
can
kIll;
WELDING
WIRE
can
cause
puncture
wounds;
HOT SURFACES
can
cause
severe
burns.

Do
not
touch
live
electrical
parts.

Shut
down
welding
power
source
and
wire
feeder
before
working
on
gun.

Disconnect
gun
from
wire
feeder before
in
specting,
maintaining,
or
servicing.

Allow
a
cooling period
before
servicing.
IMPORTANT:
.030
and
.035
in.
(0.8
and 0.9
mm)
di
ameter
wires
use
the
same
monocoll liner
and
outlet
guide.
Changing
from .030
in.
(0.8
mm)
wire
to
.035
in.
(0.9
mm)
wire
or
vice
versa
requires
changing
the
con
tact
tube
only
(see
Section
5-2).
To
change
from
.030
in.
(0.8
mm)
wire
or
.035
in.
(0.9
mm)
wire
tO
.023
in
(0.6mm)
wire
or
vice
versa,
or
to
re
place
monocoil
liner,
proceed
as
follows:
1.
Remove
nozzle.
A
slight
twist
clockwise aids
re
moval
and
installation.
2.
Cut
off
any
portion
of
electrode wire
which
extends
beyond
end
of
contact
tube.
a
CAUTION:
LOOSE
WELDING
WiRE
can
cause
Injury.

Keep
a
firm
hold
on
the wire
during
installa
tion,
removal,
and
threading
operations.
Spooled
wire has
tendency
to
unravel
rapidly
when
loosened from
the
spool.
a
WARNING:
HIGH CONCENTRATION OF
SHIELDING
GAS
can
harm health
or
kill.

Shut
off
gas
supply
when
not
in
use.
SECTION
5-
MAINTENANCE
OM-1028
Page
4