Tweco 180 Portable MIG - Manual (Page 30)

FABRICATOR 140, 180 INSTALLATION
Manual 0-4991 3-6 July 20, 2007
3.08 Polarity Changeover
!
WARNING
ELECTRIC SHOCK CAN KILL! Make certain the machine is unplugged from the power receptacle. Do not
plug machine in until told to do so in these instructions
As delivered from the factory, the output polarity is connected as DCEP (reverse polarity). The output terminals are
located on the interior panel of the welding power source.
CABLE TO GUN CABLE TO WORK
1. GMAW* – Solid Wire &
flux cored with shielding gas 1. DCEP – Reverse Polarity* 1. Connected to (+)
Pos. output terminal
1. Connected to (-)
Neg. output terminal
2. FCAW* – Self-shielding
Wire – no Shielding Gas 2. DCEN – Straight Polarity* 2. Connected to (-)
Neg. output terminal
2. Connected to (+)
Pos. output terminal
* Exception: Contact your filler metal supplier for recommended polarity.
CABLE CONNECTIONS PROCESS POLARITY
Table 3-1: Process Cable Connections
Connection for GMAW (reverse polarity DCEP)
1. Open the door to the machine.
2. Remove the polarity terminal knobs.
3. Set up the polarity (as per Table 3-1 above) by
removing the leads from the terminals and
reversing them if necessary. Refer to Figure 3-4.
4. Replace the polarity terminal knobs.
NOTE
Ensure that the polarity terminal knobs are
tightly secured and that there is no connection
between positive and negative terminals.
Connection for FCAW (straight polarity DCEN)
1. Open the door to the machine.
2. Remove the polarity terminal knobs.
3. Set up the polarity (as per Table 3-1 above) by
removing the leads from the terminals and
reversing them if necessary. Refer to Figure 3-5.
4. Replace the polarity terminal knobs.
NOTE
Ensure that polarity terminal knobs are tightly
secured and that there is no connection
between positive and negative terminals.
Polarity
Terminal
Leads
Polarity
Terminal
Knobs
Gas Hose
Normally
Connected
Figure 3-4: Connection for GMAW (reverse polarity DCEP)
Polarity
Terminal
Leads
Polarity
Terminal
Knobs
Gas Hose
Normally
Disconnected
Figure 3-5: Connection for FCAW (straight polarity DCEN)