Tweco 220 VAC 50Hz Drag-Gun - Manual (Page 21)

Operating Manual 0-2737 17 DRAG-GUN Plasma Cutter (Australia)
WARNING
Do not operate unit without filter installed.
B. Power Sour B. Power Sour B. Power Sour B. Power Sour B. Power Source Related ce Related ce Related ce Related ce Related
This system draws about 15 amps rms from the 220 VAC
service under normal operating conditions. If the 220 V
service available is saggy, pilot and cut performance will
be degraded. In some cases, the service circuit breaker
may open during use. Some things that will help:
• Use a service fused or circuit breaker for 15 amps.
• Use as short an extension cord as possible.
• Use heavy gauge extension cords (Refer to Section
4D for extension cord lengths).
• Try different outlets on different branch circuits. Use
the one that gives the strongest pilot.
C. Power Supply/T C. Power Supply/T C. Power Supply/T C. Power Supply/T C. Power Supply/Tor or or or orch Related ch Related ch Related ch Related ch Related
In some instances, the service may be good but when the
torch switch is pressed the compressor comes on but there
is no pilot. You may need to try several times before the
torch fires.
If the torch does not fire (no pilot arc) soon after the torch
switch is activated, try releasing the torch switch and let-
ting the leads bleed down before trying again. The torch
pilots best if started under low air pressure. This helps
because the torch fires at a lower voltage with lower air
pressure at the torch.
D. Cutting Related D. Cutting Related D. Cutting Related D. Cutting Related D. Cutting Related
1. Piloting
One of the features of this plasma cutter is the con-
stant DC pilot. This means the plasma arc is always
“on”- either as a pilot arc, or a cutting arc, resulting in
a very smooth, forgiving system. This also means that
the torch tip will wear fairly rapidly if you pilot for
an extended time or cut with too great a standoff (es-
sentially switching from a transferred cutting arc back
to the constant DC pilot arc).
The best way to prevent this is to pilot for no more
than 5 seconds at a time (or start with the torch in
contact with the material) and “drag cut”, that is, hold
the tip in direct contact with the material to be cut.
For some materials, holding a slight standoff (1/16")
may provide a better cut.
NOTE
Piloting is harder on parts life than actual cutting
because the pilot arc is directed from the electrode
to the tip rather than to a workpiece. Whenever
possible, avoid excessive pilot arc time to improve
parts life.
2. Torch Standoff
Improper standoff (the distance between the torch tip
and workpiece) can adversely affect tip life as well as
shield cup life. Reducing standoff will generally re-
sult in a more square cut.
NOTE
Although the DRAG-GUN will cut using stand-
off, this unit is primarily a drag-cutting machine.
6.0 MAINTENANCE 6.0 MAINTENANCE 6.0 MAINTENANCE 6.0 MAINTENANCE 6.0 MAINTENANCE
6.1 Recommended Maintenance 6.1 Recommended Maintenance 6.1 Recommended Maintenance 6.1 Recommended Maintenance 6.1 Recommended Maintenance
Schedule Schedule Schedule Schedule Schedule
WARNING
Disconnect primary power to the system before dis-
assembling the power supply.
NOTE
The actual frequency of maintenance may need to
be adjusted according to usage and the environ-
ment.
Recommended Routine Maintenance
Schedule
Daily Operational Checks or Every 6
Cutting Hours:
1. Check torch consumables. Replace if
damaged.
2. Inspect torch for any cracks or exposed
wires. Repair or replace before
proceeding.
3. Inspect input power cable for damage or
exposed wires. Repair or replace before
proceeding.
Weekly or Every 30 Cutting Hours:
1. Check for proper fan operation.
2. Blow or vacuum dust and dirt out of the
entire machine, including the air filter.
Figure 6-1 Routine Maintenance