www.parweld.co.uk
www.parweld.co.uk
11
6.4 MMA welding setup
Note:- shorting or dipping the electrode into the weld pool for
more than 2 seconds will cause the machine to reduce the
welding power to zero in order to protect the electrode.
7.0 Fault Finding
MMA welding problem
Description
Possible cause
Remedy
Gas pockets or voids
in weld metal (porosity)
(a) Electrodes are damp
(b) Welding current is
too high.
(c) Surface impurities
such as oil, grease,
paint, etc
(a) Dry
electrodes
before use
(b) Reduce
welding
current
(c) Clean
joint before
welding
Crack occurring in
weld metal soon after
solidification.
(a) Rigidity of joint.
(b) Insufficient throat
thickness.
(c) Cooling rate is too
high.
(a) Redesign
to relieve
weld joint
of severe
stresses or
use crack
resistance
electrodes.
(b) Travel
slightly
slower to
allow greater
build up in
throat.
(c) Preheat
plate and
cool slowly.
A gap is left by failure
of the weld metal to fill
the root of the weld
(a) Welding current is
too low.
(b) Electrode too large
for joint.
(c) Insufficient gap
(d) Incorrect sequence
(a) Increase
welding
current
(b) Use
smaller
diameter
electrode.
(c) Allow
wider gap
(d) Use
correct build-
up sequence
OPERA
TION
1) Press button R to select MMA welding
2) Press the toggle button (C) to move the LED to the
Output current (I) This can be adjusted from 5 to 250A
.The value is displayed on the amperage display (O).
3) Press the toggle button (R) to move the LED to
the Arc force (S) This can be adjusted from 0 to 10
Arc force prevents the electrode from sticking during
welding. The value is displayed on the multifunction
display (F). Arc force is a temporary increase of the
output current during welding when the arc is too short.
To have a smooth arc with less spatter, set the knob
to minimum (Rutile,Basic). For a more crisp arc, with
more penetration,set it to maximum.
4) Press the toggle button (R) to move the LED
to the Hot start (T) The value is displayed on the
multifunction display (F) and can be adjusted from 0 to
10. This is the temporary increase of the output current
during the start of a weld, this helps ignite the arc
quickly and reliably. Hot Start provides excellent arc
ignition without the electrode sticking and avoiding any
metallurgical default in the weld.
A
R
C
F
E
G
D
C
I
H
J K
L
S
T
