Bosch Rexroth Controls and Mid-Frequency Transformers

PST 600E – Compact power packs for stationary machines and manual welding systems

PST 600E AC controllers from Rexroth have a compact, slim design which makes them up to 60 percent smaller and lighter for applications involving stationary welding machines and manual welding stations.

PST 600 E AC controllers were designed for applications up to 500 kVA:

• Air cooled/water cooled
• Parallel input/output box with coordinated scope of functions
• High-precision primary current control without external current sensor – no more cables and connectors
• Optional slot for fieldbus module (Ethernet)
• Attractive replacement for older welding systems

PST 6000 – the cost-effective AC series for standard applications

The PST 6000 AC controllers are mechanically identical to the PSI 6300 inverter series. This also provides a low-cost migration path from AC to middle frequency at a later time. Naturally these control systems offer you the same flexibility in the I/O area and all the control functions of the entire PS 6000 system.

PST 6000 AC controllers were designed for applications up to 250 kVA:

• Air cooled/water cooled
• Optimum weld result by means of primary or secondary current control
• Competitive solution for standard applications

Bosch PSI 6000 inverters have been specifically designed for spot, projection and resistance seam welding. The extensive control functions guarantee high process reliability. The PSI family offers a variety of additional functions for welding high-strength metals, aluminum and three-member joints. The 1,000 Hz medium frequency/DC technology has proved its particular economic efficiency in many applications in contrast to other processes:

• Higher welding quality via more dynamic current control than for the AC system
• Weldability of many materials increased by more intensive energy supply
• Spatter reduced by decreased welding current and/or current time
• Electrode life lengthened thanks to lower thermal and mechanical load on the electrode caps
• Smaller and lighter transformers for integration in the electrode holders

Inverter PSI 62C0:  MF converter 9 – 54 kA, water cooled, 400 – 480 V, 50/60 Hz, preferably for connecting 100 KVA – 200 KVA transformers, with integrated control functionality, nominal current of 220 A (continuous thermal current), I/O module.

Inverter PSI 63C0: MF converter 6 – 36 kA (same design as PSI 6100), mains voltage of 400 to 480 V or 500 – 690 V, 50/60 Hz, air cooled, preferably for connecting PSG 6000 transformers, with integrated control functionality, nominal current of 110 A (continuous thermal current), I/O module.

Inverter PSI 64C0: MF converter 9 – 60 kA, water cooled, 400 – 480 V, preferably for connecting PSG 6000 transformers, nominal current of 220 A (continuous thermal current, I/O module.

Inverter PSI 65C0: MF converter 9.0 – 120 kA, water cooled, 400 – 480 V, 50/60 Hz, preferably for connecting PSG 6000 transformers, with integrated control functionality, nominal current of 660 A (continuous thermal current), I/O modules.

PSQ 6000 – for supreme quality in spot welding

The PSQ 6000 control system is designed to monitor quality performance in high-volume production operations. Intelligent current/voltage control maximizes process reliability and provides online verification of spot weld quality. The BOS 6000 operating interface includes logging and documentation features.

Control and monitoring functions are integrated in the control system. The XQR control card is available as an upgrade for older PSI 6000 series systems.

Adaptive current/voltage control for perfect welding quality

The adaptive process control system gives you added flexibility for future requirements in the welding process. By measuring current and voltage, the course of resistance and energy can also be calculated, controlled and accurately evaluated during welding. The adaptive control algorithm ensures consistent quality and reduces spatter in demanding welding applications. Expensive rework is therefore considerably reduced.

Process monitoring

Tolerance limits can be set and monitored for a number of basic process parameters: current, phase angle, electrode voltage, resistance, current time cycle, power and energy. Two consolidated variables, which summarize the basic variables, are provided to simplify system handling:

• PSF – the process stability factor indicates the stability of the welding process
• UIP – the quality factor provides an indication of actual product quality

Q-Stop logic

Patented Q-Stop logic is a very useful extension of monitoring functionality. It enables users to analyze and optimize system productivity by defining how the system reacts to repetitive faults in a program or on a particular part.

Process overview

To provide the big picture, the status of all attached welding controllers is displayed on a bar graph.