CARBONE PowerMaster256, Operator'S Manual

B-7                                OPERATION                                      B-7

OPERATING STEPS   

WELDING IN TIG MODE   

1 Connect the TIG torch and cable Twist-Mate quick 
connect plug to the Electrode/Gas 

output 

receptacle. This receptacle also contains an integral 
gas connection for the torch. Connect the work 
clamp to the work piece.   
2    Set the TIG/MMA/CUT switch to "TIG".   
3 Set the AC/DC Switch to DC for welding steel or 
stainless steel; or to AC for welding aluminum.   
4 Connect the arc start switch

(

or

 Adjustable foot 

control

 )to the Remote Control Connector.   

5 Turn on the cylinder gas valve and adjust the flow 
regulator to obtain desired flow.   
6 Turn the power switch to "ON".   
7 Preset the Output Control on the control panel to 
the maximum desired amps, as read on the digital 
meter.  
8 Depress the 

Adjustable foot control

 to energize 

the torch and establish an arc with the work piece. 
The digital meter reads the actual amps while 
welding.  

NOTE:

 When the TIG/MMA switch is set to "TIG", depressing 

the remote control will start a 0.5 second gas pre-flow before 

energizing the TIG torch. When the remote control is released 

the TIG torch is de-energized and gas flow will continue for the 

time set by the Post Flow Time control. When the polarity 

switch is set to DC, the TIG Arc Starter will turn on and off 

automatically to start and stabilize the arc. In AC the TIG Arc 

Starter will turn on with the output and remain on continuously 

until the remote control is released.   

WELDING POLARITY   

DC Electrode Negative Polarity (Direct Current 
Straight Polarity) (see FIGURE B.4) 
While Welding, there is a continuous flow of 
electrons from the electrode to the workpiece. 
This is the most used polarity, ensuring limited wear 
of the electrode, since the majority of the heat 
concentrates on the anode (workpiece). Narrow and 
deep welds are obtained with high travel speeds.   
Most materials, with the exception of aluminum and 
magnesium, are welded with this polarity.   
 

                      FIGURE B.4   
 

DC Electrode Positive Polarity. (Direct Current 
Reverse Polarity)

 (see Figure B.5)   

In this case, there is a continuous flow of electrons 
from the workpiece to the electrode. The reverse 
polarity is used for welding alloys covered with a 
layer of refractory oxide.   
With this polarity the electrode functions as anode 
and is subjected to a high degree of heat; the 
workpiece is bombardment by positive ions sent 
from the electrode which break the surface oxide.   
In Electrode Positive Polarity, high currents cannot 
be used, since they would cause an excessive wear 
of the electrode.   
 

                        FIGURE B.5   

D.C.-Pulsed TIG 

(see Figure B-6)   

 
The use of pulsed direct current allows better 
control of the weld pool during certain operating 
conditions.  
When compared with traditional TIG welding 

performed at the same average current, pulsed 
welding results in a smaller heat affected zone 
which results in fewer deformations and reduced 
chance of cracking and gas entrapment.