Tweco 250 Weldskill MIG - Manual (Page 32)

6-2 Manual No 0-5072
weldskill 250, 350 operation
December , 2008
4. COARSE VOLTAGE CONTROL SWITCH (WELDSKILL 350 ONLY)
The Coarse Voltage Control increases the voltage (in larger increments than the Fine switch) as it is rotated
in the clockwise direction.
CAUTION
The Coarse & Fine Voltage Control switches MUST NOT BE SWITCHED during the welding pro-
cess.
5. TORCH POLARITY LEAD
This lead selects the welding voltage polarity of the electrode wire. Plug it into the positive welding terminal
(+) when using steel, stainless steel or aluminium electrode wire. Plug the Torch Polarity Lead into the
negative welding terminal (-) when using gasless electrode wire. If in doubt, consult the manufacturer of
the electrode wire for the correct polarity.
6. POSITIVE WELDING TERMINAL
Positive Welding Terminal. Welding current flows from the Power Source via heavy duty bayonet type
terminals. It is essential, however, that the male plug is inserted and turned securely to achieve a sound
electrical connection.
7. NEGATIVE WELDING TERMINAL
Negative Welding Terminal. Welding current flows from the Power Source via heavy duty bayonet type
terminals. It is essential, however, that the male plug is inserted and turned securely to achieve a sound
electrical connection.
CAUTION
Loose welding terminal connections can cause overheating and result in the male plug being fused
in the terminal.
8. TORCH CONNECTOR
The MIG torch connects to this outlet.
9. OVERHEAT INDICATOR
The critical component for thermal protection is the rectifier stack, which is fitted with a thermal overload cut
out device. If the overload operates then the machine should be left to cool for approximately 5 minutes
before resuming welding. The thermal overload will not operate and there will be no danger of transformer
damage if the Power Source is operated within its duty cycle.
The WeldSkill 250 and 350 Compact Power Source has a front panel indication of Overheat (Thermal
Overload).
10. VOLTAGE CONTROL SWITCH MODE SWITCH (WELDSKILL 250 ONLY)
The Voltage Control Switch increases the voltage as it is rotated in the clockwise direction. And do not
switch it while welding is going on.