994303 - ESAB 994303 Control Transformer 117V Primary 24V CT Secondary

Technical Overview of the ESAB 994303 Control Transformer

The ESAB 994303 is a specialized control transformer designed for use within specific ESAB welding power sources. As a critical component in the electrical architecture of the machine, this transformer (abbreviated as XFMR in schematics) is responsible for stepping down the line voltage or an intermediate control voltage to a lower, safer level required by the machine's logic circuits, control boards, and auxiliary systems. The unit features a primary input winding rated for 117 Volts AC, making it compatible with standard North American control circuit designs often derived from 120V lines or tapped from main power transformers.

On the secondary side, the transformer offers a versatile output configuration described as 12-12/24CT. This indicates a center-tapped winding arrangement capable of providing 24 Volts across the full secondary or 12 Volts from the center tap to either leg. This flexibility allows it to power various subsystems that may require different voltage potentials, such as 24V relays and solenoids, or 12V logic supplies. The power rating of 7.2 VA (Volt-Amperes) indicates the maximum apparent power the transformer can deliver continuously without overheating, which is sufficient for driving standard printed circuit board (PCB) control loads in welding equipment.

Constructed with high-grade magnetic steel laminations and precision-wound copper coils, the ESAB 994303 ensures efficient energy transfer with minimal hysteresis loss. The open-frame design facilitates heat dissipation through natural convection within the welder's cabinet. When replacing a failed transformer, it is imperative to verify that the replacement matches the impedance and voltage characteristics of the original to prevent damage to sensitive downstream electronics. This OEM part guarantees adherence to ESAB's rigorous manufacturing tolerances and safety standards.

Technicians installing this component should observe standard electrical safety protocols, including verifying isolation from mains power and discharging any capacitors in the circuit. The transformer typically connects via spade terminals or direct solder points depending on the specific machine assembly, and proper polarity must be maintained where applicable in rectified circuits following the AC output.