WTC 901UNO Resistance Welding Controller Product Description

Overview

WTC 901UNO is a single-channel resistance welding controller from WTC UNO series, designed to work with MFDC inverters such as 902‑1333GVR for spot, projection and seam welding. This WTC welding controller is the master logic unit of the welding cell, responsible for weld schedule storage, firing sequence, closed‑loop current regulation and fault diagnosis. 901UNO is a legacy control unit widely used in automotive body welding lines, robotic welding stations, mainly for production line overhaul and spare‑part replacement of existing WTC UNO welding systems.

Features

WTC 901UNO resistance welding controller supports multiple weld schedules with adjustable squeeze, weld, hold and off time parameters. This WTC welding controller communicates with the matched MFDC inverter via dedicated control link to set current reference and receive real‑time welding feedback. 901UNO integrates digital I/O ports for PLC trigger, weld start signal, ready signal and fault alarm output. The WTC welding controller supports constant current, constant voltage and constant power control modes, with adaptive heat compensation for electrode wear and mains fluctuation. This controller supports optional fieldbus communication for MES data upload and weld quality traceability. 901UNO has built‑in waveform monitoring and fault logging functions for on‑site troubleshooting.

Specs

WTC 901UNO resistance welding controller

• Brand: WTC (Welding Technology Corp)

• Series: UNO

• Model: 901UNO

• Channel: Single weld channel

• Matching inverter: GEN6 MFDC series (902‑1333GVR etc.)

• Control mode: Constant current / constant voltage / constant power

• Schedule storage: Multiple weld programs

• I/O: 24VDC discrete input and output

• Communication: Dedicated weld link to MFDC inverter, optional fieldbus

• Operating environment: Workshop cabinet installation, dust and splash protection

Principle

WTC 901UNO resistance welding controller receives a weld start trigger signal from robot or PLC. It loads the selected weld schedule and sends current setpoint to the MFDC inverter. The inverter samples the actual welding current and feeds back to 901UNO. The controller compares the feedback value with target value and dynamically adjusts the inverter output to maintain stable welding energy throughout the weld cycle. After the weld cycle finishes, the controller outputs weld complete signal. If current deviation, inverter fault or overheat alarm is detected, the controller terminates firing immediately and locks the fault code.

Applications

WTC 901UNO resistance welding controller is deployed on automotive assembly welding lines, robotic spot welding cells and projection welding stations. This WTC welding controller is used for steel sheet, galvanized sheet and aluminum alloy resistance welding. 901UNO fits welding cell maintenance and spare replacement of UNO series single‑channel welding control systems.

Installation & Maintenance Notes

Follow official WTC UNO service manuals during installation of WTC 901UNO welding controller. Verify wiring with MFDC inverter, robot I/O and safety interlock circuit. Back up all weld schedules before controller replacement. After replacement, perform dry run and current calibration test. Periodically check 24V auxiliary power, communication cable shielding and connector tightness. Confirm exact part number 901UNO before spare‑part swap‑out to verify compatibility with the existing GEN6 inverter model.