Tweco Thermal Arc TA 500 - Manual (Page 31)

Manual No 0-0470 3-5 Operation
5. In continuous cutting applications, it is often neces-
sary to manifold 4 to 6 CO
2
cylinders together to
maintain pressure.
6. Because of the swirl of the plasma gas in the torch,
the right-hand side of the cut (in relation to the
torch travel, as shown in Fig. 3-H) is normally of
better quality. A reverse swirl electrode is available
for applications requiring the better quality be on
the left side of the cut (in relation to the torch travel).
Torch Travel
Scrap
(Beveled)
Side
Better
(Square)
Side
Figure 3-H Direction of Gas Flow Using Standard Gas
Distributor
WARNINGS
FREQUENTLY REVIEW THE SAFETY PRECAU-
TIONS GIVEN AT THE FRONT OF THIS
MANUAL.
It is not enough to simply move the ON/OFF
switch on the Control Panel to its OFF position
when cutting operations have been completed.
Always open all power disconnect switches 5
minutes after the last cut is made.
3.4 Cutting and Speed Selection
The desired cutting current and the speed at which the torch
is moved along the line of the cut depends on the thickness
and composition of the workpiece. Use Table 3-B as a start-
ing guide to establish the proper cutting speed for the mate-
rial being cut.
COMMON CUTTING FAULTS
Listed below are common cutting problems followed by prob-
able causes of each. If problems are caused by the TA-500
system, refer to the trouble shooting section (Section 4).
1. Insufficient Penetration
a. Cutting speed too high
b. Current too low
2. Main Arc Extinguishes
a. Cutting speed too slow
b. Standoff too high
3. Dross Formation
a. Improper gas pressure or mixture
b. Improper cutting speed
c. Faulty electrode or tip
d. Current too high
e. Stand-off too low
4. Burned-Out Tips
a. High cutting current
b. Damaged or loose cutting tip
c. Contact with work
d. Heavy spatter
e. Low plasma gas pressure
f. Improper selection of SOFT/NORM/PIERCE