673502 - ESAB 3-Pole 75A Welding Contactor 115V Coil

Technical Overview of the ESAB 673502 Contactor

The ESAB 673502 is a specialized electromechanical contactor engineered for the rigorous demands of industrial welding equipment. As a critical component in the power distribution circuit of welding machines, this device is responsible for making and breaking the high-current power lines that feed the main transformer or inverter power section. The unit features a 3-pole (3P) configuration, making it specifically designed for switching three-phase power supplies, which are standard in heavy-duty industrial welding environments.

Technically, the contactor is rated for a continuous operational current of 75 Amperes. This rating indicates the maximum current the main contacts can carry without overheating or sustaining damage under normal duty cycles. The actuation mechanism is driven by a solenoid coil operating at 115 Volts AC (VAC). When the control circuit energizes this coil—typically when the welder's trigger is pulled or the machine is powered on—the magnetic field closes the three main contacts simultaneously, allowing power to flow. The 115 VAC coil voltage is a standard control voltage derived from the machine's control transformer, ensuring compatibility with a wide range of North American equipment designs.

Maintenance professionals should note that contactors are wear items. Over thousands of cycles, the electrical arc generated during the making and breaking of contacts can cause pitting, carbon buildup, or uneven wear on the silver-alloy contact pads. The ESAB 673502 is built with durable materials to withstand this arcing better than standard general-purpose contactors, but periodic inspection of contact resistance and mechanical movement is recommended. This OEM-grade component ensures that the replacement meets the specific inductive load handling characteristics required by welding power sources, which often present more challenging electrical loads than simple resistive heaters or motors.

Specifications Summary

• Configuration: 3-Pole (Normally Open)
• Current Rating: 75 Amps
• Control Voltage: 115 VAC Coil
• Mounting: Panel mount compatible