MFDC/MFAC Inverter Weld Control

Main Features

CSI Inverters for both MFDC and MFAC

• Power inverter using IGBT technology for medium–frequency output, 2 color LCD and 256 color LCD depending on the CS-I unit specified  and via PC or via field bus.
• The output frequency selectable by the user from 1 kHz to 10 kHz (15 kHz*) is suitable to drive MFDC transformers.

• MFDC welding 1KHz to 20Khz and from 150 amp to 4,000 amp available
• MFAC welding 30hz through 600 Hz 200 Amp to 2,500 amp

• Four independent auto calibrations of machine’s secondary circuits or with manual setting.
• User selectable current measurement on primary or on secondary.
• The current loop gain is user adjustable.
• Six different modes of current regulation are available:
– Duty fixed pro thousand D‰
– Duty pro thousand with compensation of power line voltage fluctuation, V‰
– Constant Current IK
– Constant Power PK
– Constant Energy EK
– Adaptive AD
• The weld current can be set by external voltage reference 0-10V or via field bus.
• User selectable set, management and parametrization of the cycle for spot weld machines or for seam weld machines.
• Time management in periods or in milliseconds.
• Galvanic insulation of input and output sections.
• Setup and run of 128 (256*) programs, callable by external input, internal, sequential or associated with the start cycle IC1 or IC2 and via field bus if installed.
• Communication line Binary Input, USB or Ethernet* for the connection to Personal computer or TFT terminal.
• Communication expansion Field Bus*: Profibus -Profinet I/O
-Device Net -CANopen -Modbus/ RTU -Modbus/TCP -EtherNet/IP -EtherCat
• Start cycle with concomitance: (dual pushbutton inputs) or pedals.
• Monitoring (for quality control) of the limits of the welding current in spot-weld and in seam weld mode.
• Programmable function of continuous self-increase or decrease of the weld current to compensate the electrodes wear under variable curve for up to four pairs of electrodes (four transformers) or for tungsten electrodes (Decrease); (Auto-Step).
• DRESS Electrodes counter with signaling and reset suitable for four electrodes pair.
• Weld counter up to 999999, with alarm and lock function.
• Four solenoid valves flexibly associated to pre-squeeze and squeeze.
• Proportional valve driving circuit, galvanic insulated, with % setting Pressure(bar) or Force(dN).
• Proportional valve full-scale setting (99%) from five to 10V.
• Forging solenoid valve output.
• Output for pre-stroke solenoid valve with pre-stroke function.

• Available association of pressure in Pre-squeeze, Squeeze, Preheat, Welding, Forging and Rest, by mean of the proportional valve (pressure cycle) in %, Pressure(bar), Force(dN).
• Power IGBT water-cooling system with integrated monitoring and drive of the cooling water solenoid valve.
• Possibility of external power supply 24 V. DC to support the field bus activities in case of power line failure.
• Heatsink temperature monitoring.
• Transformer power diodes temperature monitoring.
• Cool water Flow monitoring.
• Automatic check with eventual error signaling for open Rogowski coil.
• Check and possible signaling of weld start while the electrodes are still opened.
• Resistance check (Test) for:
– Opened electrodes.
– Closed electrodes (wait for resistance of start).
– Weld resistance 1.
– Weld resistance 2.
– Final resistance of weld spot.
• Management, via CAN BUS of four wait inlets and of four additional drive outlet, before the pre-squeeze time and after the hold time*.
• Concatenated programs run.
• Graphic plot on the terminal of the weld parameters.
• Test functions of inlets and outlets.
• Error and weld log windows with time date and weld number records, stored in baked up memory.
• Automatic duplication of weld program in more additional programs.
• Management via CAN BUS of the linear displacement of the electrodes with or without wear recovery. Pressure or force management by mean of proportional valve or load cell with feedback.*
• Enable or disable, by mean of flags, of the display and use of the weld cycle parameters.
• In seam weld mode: set of start, slope, end slope currents
• In seam weld mode: three remote or via fieldbus recallable currents*.
• In seam weld mode: independent check function for each current.
• In seam weld mode: independent management of each current, of the weld pressure in %, Pressure(bar) or Force(dN)
• In seam weld mode: Management of four rotation speeds.
• A special cycle for the weld of lead/acid batteries is available.
• Possibility of choice among five languages on the programming unit display. Additional languages upon request.
• Web Server.