Tweco 300A External Welding Contactor Switch

Upgrade Your Welder for Safety and Performance

Take control of your welding arc with the Tweco Hefty Contactor, 300 Amp. If you are working with a welding machine that keeps the electrode "hot" at all times—such as many engine-driven welders or older shop power sources—you know the risks involved. Accidental arcs can damage your workpiece, ruin your tip, or cause injury. The Tweco Hefty Contactor (SKU: 870133) eliminates these risks by adding a heavy-duty, trigger-activated switch to your system, ensuring the wire or stick electrode remains cold until you are ready to weld.

This 300-amp unit is a must-have accessory for welders running suitcase wire feeders or performing mobile fabrication. It acts as the bridge between your power source and your torch, closing the circuit only when you pull the trigger. This feature is essential for true semi-automatic welding performance and significantly reduces the stress of managing a live wire during repositioning. Whether you are running solid wire MIG or heavy flux-cored wire, the Hefty Contactor delivers reliable power switching time after time.

Built by Tweco, a leader in welding products, this contactor is designed to withstand the abuse of daily use. Its compact yet tough casing protects the mechanism from impact and debris. It works effectively with both CC and CV power sources, making it a versatile addition to your tool arsenal. Don't settle for always-hot terminals; upgrade your rig with the Tweco Hefty Contactor and experience the convenience and safety of a cold-electrode setup.