Prest-O-Lite 550, Instruction Manual

Page: 27 / 44

27
WHEN THE ARC BREAKS
THROUGH THE WORK, BRING THE
TORCH TO AN UPRIGHT POSI-
TION AND PROCEED TO CUT.
TO START A PIERCE, TILT THE TORCH
TO PREVENT MOLTEN MATERIAL FROM
COMING BACK AGAINST AND DAMAG-
ING THE TORCH.
1
2
CAUTION: Locate the console at least 10-ft. from the cutting
work area. Chips and hot slag from the cutting
operation can damage the console.
After placing the primary (wall) switch to the ON position and
making control and air pressure adjustments as described
above, proceed as follows:
1. Touch the tip of the torch to the workpiece (or within
0.020-in. of the workpiece) holding the torch at about
15- 30
°
angle to avoid damaging the tip.
2. Depress the torch switch. (Air and high frequency should
energize.)
3. Two seconds after depressing torch switch, the plasma arc
will start cutting.
4. After starting the cut, the tip can be dragged along the
workpiece if cutting up to 1/4'’ thick material. When cut-
ting material greater than 1/4'’, maintain a 1/8'’ tip-to-work
(standoff) distance.
5. When ending a cut, the torch switch should be released
and lifted off the workpiece just before the end of the cut
to minimize double-arcing which can damage the tip. This
is to prevent high frequency from reigniting after cutting
arc extinguishes.
6. In the postflow mode, the arc can be restarted immediately
by depressing the torch switch. The two second preflow
will automatically cancel.
cutting speed range — prest-o-lite ® 550
(using air with XT consumables @ 75 psi)
Output Cutting
Thickness Current Speed
Material (In.) (Amps) (ipm)
Carbon 1/16 30 180
Steel 1/8 30 75
(AISI 1020) 1/8 35 85
1/4 35 30
3/8 35 15
1/2 35 12
Stainless 1/16 30 200
Steel 1/8 30 85
(AISI 304) 1/8 35 85
1/4 35 30
3/8 35 14
1/2 35 10
Aluminum 1/16 30 200
(6061) 1/8 30 85
1/8 35 85
1/4 35 30
3/8 35 15
1/2 35 12
NOTE: The speeds given here are typical for best quality cuts. Your actual
speeds may vary depending on material composition, surface condi-
tion, operator technique, etc. If cutting speed is too fast, you may
lose the cut. With slower speeds excessive dross may accumulate.
If speed is too slow, the arc may extinguish. Air cutting typically
produces a rough face on stainless steel and aluminum.
figure 4-4. piercing Technique using the pT-31Xl
sectioN 4 operatioN