Lincoln Electric IM588 PCT80, PCT80M & PCT80R Plasma Torches - Manual (Page 11)

B-1 OPERATION B-1
When plasma cutting, it is necessary to wear
proper eye, head and body protection.
PREHEAT TEMPERATURE FOR PLASMA
CUTTING
Preheat temperature control is recommended for opti-
mum mechanical properties, crack resistance and
hardness control. This is particularly important on high
carbon alloy steels and heat treated aluminum. Job
conditions, prevailing codes, alloy level, and other con-
siderations may also require preheat temperature con-
trol. The following minimum preheat temperature is
recommended as a starting point. Higher tempera-
tures may be used as required by the job conditions
and/or prevailing codes. If cracking or excessive hard-
ness occurs on the cut face, higher preheat tempera-
ture may be required. The recommended minimum
preheat temperature for plate thickness up to 1/2”
(12.7mm) is 70F (21.1C).
USER RESPONSIBILITY
Because design, fabrication, erection and cutting vari-
ables affect the results obtained in applying this type of
information, the serviceability of a product or structure
is the responsibility of the user. Variation such as plate
chemistry, plate surface condition (oil, scale), plate
thickness, preheat, quench, gas type, gas flow rate and
equipment may produce results different than those
expected. Some adjustments to procedures may be
necessary to compensate for unique individual condi-
tions. Test all procedures duplicating actual field con-
ditions.
OPERATION
A. Connect the ground lead to the material to be cut.
B. Turn the Pro-Cut “ON” with the power switch on the
front of the machine.
C. Press the Purge switch and hold. Adjust the regu-
lator until the pressure gage reads 70 psi (4.8 Bar.).
Release the Purge switch and the air flow will stop.
The pressure may increase by 5 to 10 PSI after air
flow stops but this is normal.
D. Adjust the output to the desired level. Refer to the
appropriate Lincoln Process and Procedure
Guidelines for recommended output, standoff, noz-
zle and cutting technique for your application.
E. Activate the trigger.
• If the air was not already flowing, the Pro-Cut will
allow the air to flow for two seconds before the
pilot arc is started. This is called PREFLOW.
• If the trigger was activated during postflow then
a pilot arc will start
instantly.
F. Bring the pilot arc close to the material to be cut.
Once the torch is about 1/4” to 1/2” away from the
work piece the arc will automatically transfer to the
work and the Pro-Cut will regulate output to the set-
ting on the dial. It is best to minimize the pilot arc
time in order to prolong consumable life. Starting at
the edge of the work piece instead of piercing the
material will also increase consumable life.
G. Release the trigger when the cut is complete. Air
will continue to flow for 10 seconds to cool the
torch. This is called POSTFLOW.
PLASMA TORCH
WARNING