04 Options And Accessories; 05 Introduction To Plasma - ESAB A120 Operating Manual

CUTMASTER A120
12 VDC circuit rating
E. Type Cooling
Combination of ambient air and gas stream through
torch.
F. Torch Ratings
Automated / Machine Torch Ratings
Ambient
Temperature
100% @ 100 Amps @ 400 scfh
Duty Cycle
80% @ 120 Amps @ 400 scfh
Maximum Current
Voltage (V )
peak
Arc Striking Voltage
Manual Torch Ratings
Ambient
Temperature
Duty Cycle 100% @ 120 Amps @ 400 scfh
Maximum Current
Voltage (V )
peak
Arc Striking Voltage
G. Gas Requirements
Automated, Manual and Machine Torch Gas
Specifications
Gas (Plasma and Secondary) Compressed Air
Operating Pressure
Refer to NOTE
Maximum Input Pressure
Gas Flow (Cutting and
Gouging)
WARNING
!
This torch is not to be used with
oxygen (O
NOTE!
Operating pressure varies with torch
model, operating amperage, and torch
leads length. Refer to gas pressure set-
tings charts for each model.
H. Direct Contact Hazard
For standoff tip the recommended standoff is 3/16
inches / 4.7 mm.
2T.04 Options And Accessories
For options and accessories, see section 6.
2T-2
104° F
40° C
120 Amps
500V
7kV
104° F
40° C
120 Amps
500V
7kV
60 - 95 psi
4.1 - 6.5 bar
125 psi / 8.6 bar
300 - 500 scfh
142 - 235 lpm
).
2
INTRODUCTION
2T.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 electrically conductive. The plasma arc
cutting and gouging 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.
_
Power
Supply
+
C
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
A
B
Workpiece
A-08331
0-5430