Tweco PAK 15XC - Manual (Page 45)

Manual 0-2251 41 OPERATION
4.5 PLASMA CUTTING OPERATION (continued)
The auto-restart function provides an immediate pilot arc
restart during post-flow if the torch is brought within
range of the workpiece. The power supply can be set up to
provide a variety of optional auto-restart settings.
• Auto-Restart On/Off - The auto-restart function can be
switched off completely so that the torch must be re-
activated (via torch switch or control device) to restart
the pilot arc when the main arc is interrupted.
• Auto-Restart Normal/Delayed - Normal mode pro-
vides an immediate pilot arc restart when the main arc
is interrupted. Delayed mode provides a gas pre-flow
each time before the pilot arc restarts.
• Pre-Flow Delay - Pre-flow is the time interval from
when the torch is activated (start of gas flow) to pilot
arc initiation. Pre-flow duration is factory-set to two
seconds, but can be re-set to four, seven, or ten seconds
as desired.
• Post-Flow Delay - Gases continue to flow for a period
of time after the main cutting arc is interrupted and the
torch remains activated. Post-flow is factory-set to ten
seconds, but can be re-set to five, twenty, or forty
seconds as desired.
In machine torch operation, optional auto-restart settings
may be useful where:
1. The system is used for direct replacement of units not
having auto-restart for use with motion control de-
vices.
2. Torch parts life may improve without auto-restart in
some applications by reducing excessive pilot arc time.
3. In some shape-cutting applications, immediately
restarting the main arc after the torch passes beyond
the desired cutting line (or between cuts) may not be
desirable.
4. Extended leads may require longer pre-flow duration.
5. Other special applications require various arrange-
ments.
Pre-Flow Delay
Post-Flow Delay
Normal/Delayed
On/Off
Auto-Restart Options
Applications
(continued)