Tweco SL100 - Manual (Page 15)

Manual 0-2962 2-3 INTRODUCTION
2.04 Options And Accessories
These items can adapt a standard system to a particular
application or further enhance performance (refer to Sec-
tion 6 for ordering information).
• Spare Parts Kits - Various kits containing replacement
consumable torch parts.
• Deluxe Cutting Guide Kit - Easy add - on attachments
for precise straight line, circle cutting, and beveling.
Includes carrying case.
• Trigger Guard Kits (for hand torches) - These offer
additional protection from accidental activation of
the torch switch.
• 1 - 3/8" Mounting Tube (for machine torches)
• Pinion Assembly (for machine torches)
• Computer Control (CNC) Cable 25 Ft / 7.6 m or 50
Ft / 15.2 m (for machine torches)
• Remote Pendant Control Assembly - for machine
torch applications. Hand Pendant Control has 20 ft.
(6.1 m) cable which provides ON & OFF signals to
the Power Supply.
• Extension Cable for Hand Pendant Control - 25 ft /7.6
m cable which can be added to the Hand Pendant
Control cable to provide a total control cable length
of 50 ft / 15.2 m.
• Leads Extensions for torches with ATC connectors
• Leather Leads Covers
2.05 Introduction to Plasma
A. Plasma Gas Flow
Plasma is a gas which has been heated to an extremely
high temperature and ionized so that it becomes elec-
trically conductive. The plasma arc cutting and goug-
ing processes use this plasma to transfer an electrical
arc to the workpiece. The metal to be cut or removed
is melted by the heat of the arc and then blown away.
While the goal of plasma arc cutting is separation of
the material, plasma arc gouging is used to remove
metals to a controlled depth and width.
In a Plasma Cutting Torch a cool gas enters Zone B,
where a pilot arc between the electrode and the torch
tip heats and ionizes the gas. The main cutting arc
then transfers to the workpiece through the column
of plasma gas in Zone C.
A-00002
Workpiece
Power
Supply
+
_
C
B
A
Typical Torch Head Detail
By forcing the plasma gas and electric arc through a
small orifice, the torch delivers a high concentration
of heat to a small area. The stiff, constricted plasma
arc is shown in Zone C. Direct current (DC) straight
polarity is used for plasma cutting, as shown in the
illustration.
Zone A channels a secondary gas that cools the torch.
This gas also assists the high velocity plasma gas in
blowing the molten metal out of the cut allowing for a
fast, slag - free cut.