Tweco ArcMaster 401S - Manual (Page 53)

ARCMASTER 401S POWER SOURCE
Manual 0-5345 4-15 BASIC WELDING GUIDE
FAULT CAUSE REMEDY
6 Electrode melts or oxidizes
when an arc is struck.
A Torch lead connected
to positive welding
terminal.
A Connect torch lead to negative welding
terminal.
B No gas flowing to
welding region.
B Check the gas lines for kinks or breaks
and gas cylinder contents.
C Torch is clogged with
dust or dirt.
C Clean torch.
D Gas hose is cut. D Replace gas hose.
E Gas passage contains
impurities.
E Disconnect gas hose from the rear of
Power Source then raise gas pressure
and blow out impurities.
F Gas regulator turned
off.
F Turn on.
G The electrode is too
small for the welding
current.
G Increase electrode diameter or reduce
the welding current.
H Power source is set for
STICK welding.
H Set Power Source to a GTAW operating
mode.
7 Dirty weld pool A Electrode contami-
nated by contact with
work piece or filler rod
material.
A Clean the electrode by grinding off the
contaminates.
B Work piece surface has
foreign material on it.
B Clean surface.
C Gas contaminated with
air.
C Check gas lines for cuts and loose fitting
or change gas cylinder.
8 Poor weld finish Inadequate shielding
gas.
Increase gas flow or check gas line for
gas flow problems.
9 Arc start is not smooth. A Tungsten electrode is
too large for the weld-
ing current.
A Select the right size tungsten electrode.
Refer to Table 4-3 Tweco Tungsten Elec-
trode Selection Chart.
B The wrong electrode
is being used for the
welding job.
B Select the right tungsten electrode type.
C Gas flow rate is too
high.
C Select the right rate for the welding job.
Refer to Table 4-6.
D Incorrect shielding gas
is being used.
D Select the right shielding gas.
E Poor work clamp con-
nection to work piece.
E Improve connection to work piece.
10 Arc flutters during TIG
welding.
Tungsten electrode is
too large for the weld-
ing current.
Select the right size tungsten electrode.
Table 4-7