K938-1 - K930-2 TIG Module Contactor Upgrade Kit

Technical Overview: K938-1 Contactor Kit for K930-2

The Lincoln Electric K938-1 Contactor Kit is a specialized hardware assembly engineered to expand the functionality of the K930-2 TIG Module. This kit is specifically required when the TIG module is paired with a welding power source that does not possess an internal contactor or remote output control. In standard configuration without this kit, such a power source would supply continuous voltage to the TIG torch, leaving the electrode electrically 'hot' at all times. The K938-1 solves this issue by introducing a heavy-duty contactor into the output circuit, effectively isolating the torch electrode from the power source until the weld cycle is intentionally initiated.

Functionally, the kit installs directly inside the K930-2 TIG Module housing, utilizing pre-designated mounting points and terminal connections for a secure fit. Once integrated, the contactor is actuated by the Amptrol (foot or hand control) connected to the module. When the operator depresses the Amptrol, the contactor closes, completing the circuit and energizing the electrode. Conversely, releasing the Amptrol opens the contactor, cutting power to the torch immediately. This 'cold electrode' capability is standard on modern TIG inverters but is often missing from constant current (CC) stick machines or older generators used for TIG welding.

The K938-1 is critical for applications requiring precise arc initiation and termination. Without a contactor, the operator must break the arc by pulling the torch away, which can disturb gas shielding and lead to weld defects or tungsten contamination. With the K938-1 installed, the arc can be extinguished while maintaining gas post-flow shielding over the weld puddle, as the gas solenoid and contactor are synchronized through the module's control logic. This results in cleaner stop-starts and higher quality X-ray quality welds.

This kit includes the necessary contactor assembly and wiring harness components required for the retrofit. It is designed to handle the rated output of the K930-2 module, ensuring no bottleneck in amperage throughput. For welders utilizing the K930-2 to convert standard DC power sources into high-frequency TIG setups, the K938-1 is a mandatory component for achieving full remote contactor control and ensuring compliance with standard TIG safety practices.