Specifications

SECTION
5
-
TROUBLE SHOOTING
TROUBLE SHOOTING
GAS
METAL-ARC WELDING
PROCESSES
AND
EQUIPMENT
INTRODUCTION
When
troubleshooting gas
metal-arc
welding
process
and
equipment
problems
it is
well
to
isolate and
classify
them
as
soon as
possible
into
one
of
the
following
categories:
A.
PROBLEM
Control/feeder
stops
feeding
electrode wire while
welding.
PROBABLE
CAUSE
1.
Primary
line
fuse
blown.
2.
Wire
control/feeder.
a.
Control
relay
defective.
b.
Protective fuse
blown.
c.
Wire
drive
roll
gears
misaligned.
-
d.
Drive
roll
pressure
too
great.
e.
Spindle
friction
too
great.
f.
Excess
loading
of
drive
motor.
g.
Drive
roll
gears
worn;
slipping.
h.
Drive
motor
burned
out.
3.
Torch
And
Casing
Assembly.
a.
Casing
liner
dirty,
restricted.
b.
Broken
or
damaged
casing
or
liner.
c.
Torch
trigger
switch
defective
or
wire
leads
broken.
d.
Contact
tube
orifice
restricted;
burnback
of
electrode.
e.
Friction
in
torch.
B.
PROBLEM:
Electrode
wire
feeds
but is not
energized.
No
weld
ing
arc.
PROBABLE
CAUSE
1.
Primary
Line
Fuse
Blown.
2.
Power
Source.
a.
Contactor
plug
not
tight
in
socket.
b.
Contactor control
leads
broken.
c.
Remote-Standard
switch
defective
or
in
wrong
position.
d.
Primary
contactor
coil
defective.
e.
Primary
contactor
points
defective.
f.
Welding
cables
loose
on
terminals.
g.
Ground
connection
loose.
3.
Wire
Control/Feeder.
a.
Contactor
plug
not
properly
seated.
b.
Contact
relay
defective.
C.
PROBLEM:
Porosity
In the weld
deposit.
PROBABLE
CAUSE:
1.
Dirty
base
metal;
heavy
oxides,
mill
scale.
2.
Gas
cylinder
and
distribution
system.
a.
Gas
cylinder
valve
off.
b.
Regulator
diaphragm
defective.
c.
Flowmeter
cracked
or
broken.
d.
Gas
supply
hose connections
loose.
e.
Gas
supply
hose
leaks.
f.
Insufficient
shielding
gas
flow.
g.
Moisture in
shielding
gas.
h.
Freezing
of
CO2
regulator/flowmeter.
3.
Wire
control/feeder.
a.
Gas
solenoid
defective.
b.
Gas
hose
connections
loose.
4.
Torch
and
Casing
Assembly.
a.
Gun
body
and/or
accessories
aspirating
atmos
phere
or
air.
b.
Contact
tube
extended
too
far.
c.
Nozzle
to
work
distance too
great.
d.
Improper
torch
angle.
e.
Welding
speed
too
fast.
f.
Electrode
not
centered in
nozzle.
5.
Improper
Electrode
Wire
Composition.
D.
PROBLEM:
Welding
Electrode
wire stubs
into
workplece.
PROBABLE
CAUSE
1.
Power
Source.
a.
Excessive
slope
numerical
values
set.
b.
Arc
voltage
too
low.
2.
Wire
Control/Feeder.
a.
Excess
wire
feed
speed.
E.
PROBLEM:
Excessive
spatter
while
welding.
PROBABLE
CAUSE:
1.
Shielding
Gas
System.
a.
Excessive
gas
flow
rates.
b.
Insufficient
gas
flow.
2.
Power
Source.
a~
Excessive
arc
voltage.
b.
Insufficient
slope
setting
value.
3.
Torch
contact tube recessed in nozzle too
far.
4.
Improper
electrode.
F.
PROBLEM:
Weld
bead
appearance
indicates
need
for
more am
perage
and/or
larger
bead.
PROBABLE CAUSE:
1.
Power
Source.
a.
Volt-ampere
condition
too
low.
G.
PROBLEM:
Weld
bead
appearance
indicates need
for
less
am
perage
and/or
smaller
bead.
PROBABLE
CAUSE
1.
Power
Source.
a.
Volt-ampere
condition
too
high.
1.
Electrical
2.
Mechanical
3.
Process
This
eliminates
much
needless lost
time
and
effort.
The data collected
here
dicusses
some
of
the
common
prob
lems
of
gas
metalarc
welding
processes.
A
little
thought
will
probably
enable
solving
the
particular
problem
through
the
information
provided.
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 manufacturers
recommendations
should
be
strictly
adhered
to
and
followed.
Pa~
10