Resistance welding –
efficient and of the highest quality

RETROFIT EUROPA® sets new standards – in resistance welding. Welding processes in the industry require maximum process reliability and quality. The PRC 7000 welding controllers and the PSG 6000 welding transformers from Rexroth – this is much more than just a proven control and monitoring concept: Users benefit from fast commissioning, maximum availability and energy efficiency, ease of use and maximum flexibility. 80% of automotive manufacturers worldwide rely on the performance of Rexroth spot welding controls.

Our possibilities

  • Up to 90% faster commissioning compared to conventional technology
  • Efficient operation and diagnostics with PRI 7000 software
  • Highest weld quality due to optimized programming, control and monitoring functions
  • Up to 10 000 welding tasks, flexibly programmable with individual monitoring
  • Maximum energy efficiency through state-of-the-art power electronics: Welding reduces power loss by 30% compared to conventional technology, even 50% during production breaks
  • Open system architecture with integrated application layer and servo-tapping functionality
  • Flexibly configurable hardware:
    • two performance classes available
    • each with air and water cooling
    • Can be combined with various fieldbus modules
    • expandable with bus couplers and I / O modules

Further system components

Further system components from the product portfolio of Rexroth extend the functional possibilities of the welding control:

  • Fieldbus coupler and I / O modules allow the connection of operating and display elements and other discrete and analogue signals
  • Servo drives control servo-electric motors for the pincer stroke and / or electrode cutter
  • The safety zone module monitors the safety devices and, if necessary, ensures safe movement of the welding tongs
  • Pliers memory modules store data and transmit signals from the welding gun to / from the welding control if necessary

Welding transformers PSG complete the powerhouse:

Welding transformers PSG complete the powerhouse:

  • Standardized platform transformers for the automotive industry
  • Optimal power transmission with low losses
  • Monitoring function matched between welding control and transformer
  • A wide variety of applications thanks to compact design and low weight
  • Nine power classes from 94 … 250 kVA / 20% ED
  • Output DC voltage 9.0 / 14.0V
  • Connection voltage designed for 400 V … 690 V networks
  • Different versions of power and signal plugs

Why welding at medium frequency?

For resistance welding, currents in the kiloampere range are needed. For this purpose, a low voltage (eg 9 V) with high current intensity is generated by means of a welding transformer from the mains voltage (eg 400 V). In classic alternating current welding with mains frequency (50 or 60 Hz), current and welding time are controlled by means of a phase control using a thyristor controller. This has the disadvantage that you can set times and current control in steps of a minimum of 10 ms (or 8.3 ms). This is often too crude for precise control. The phase control generates a sinusoidal current with gaps. Direct current would bring the energy into the material more quickly and more uniformly. Medium frequency welding combines the advantages of higher operating frequency and direct current. A power converter generates a regulated square-wave voltage in the kilohertz range from the mains voltage. This is transformed down by welding transformer and rectified on the secondary side. The result is a nearly rectangular current pulse with low residual ripple, which can be set in millisecond steps.

“RETROFIT EUROPA® – your professional partner for resistance welding with medium frequency”