theme graphic - Resistance Welding Machine



Resistance Welding Machine

Digital 3 Phase DC Welding Machine

Breakthrough Technology

Energy Ssaver

  • Three phase balanced input
  • Unity power factor
  • Lower connected power
  • Higher efficiency low demand KVA
  • DC secondary current

Precise and Controlled

  • Weld time precision of 1 millisecond
  • Current and voltage feedback
  • IGBT controlled digital circuitry

Technological Marvel

  • No bulky transformers inside
  • No bank of capacitors
  • Suitable for any mechanical fit up
  • Available in 2500 amps., 6000 amps. and 12000 amps. models

Best Suitable For

  • Projection welding
  • Precise small parts welding
  • Copper welding
  • Aluminium welding
  • Switchgear parts

Why To Go For It?



While working with conventional two phase AC welding machines, we experience difficulty in connected power and phase balance. To overcome is problem, three phase balance input is an answer.

In AC machine KVA demand is dependant of geometry of secondary circuit, size & material of conducting components, presence of magnetic material fixtures in secondary loop. Impedance of this loop need to be minimized for minimum KVA demand for delivering welding current at welding point. AC machines need to be selected for minimum throat depth. The reactive power is consumed to maintain magnetic field around conductors, work piece and fixture. These induced current losses adds opposition to welding current . One method of eliminating this effect is DC secondary current.

In DC type machines current is function of resistance of secondary path. Being a DC system, impedance is not playing role in this case. Power is saved as lower power loss is experienced by the machine to flow current upto application point.

Technological Marvel

Here the three phase AC line power is first rectified by full wave bridge rectifier. Three phase input voltage 440 V generates 600 V DC. This DC bus is now single phase. This bus is connected to H bridge of IGBTs. The bridge inverts at 1000 Hz nominal frequency and this wave form is again converted to high power DC generating currents at lower voltages from 2500 amps. to 12000 amps.

As the controller is operating at higher frequency, it is now possible to control the cycle to precision of 1 millisecond. This eliminates interruption of welding current which is inherent in AC systems. Thyristor controlled AC system need to wait till next half cycle making heating and cooling during welding and nugget formation. In present system the weld current is continuous, this facilitate to attain melting temperatures quickly and avoid thermal shocks during welding giving more perfect weld, also saves energy as the heating is continuous. This is more important in welding of ‘high conductive’ metals like copper and aluminium. These metals need quick melting temperatures as the heat carried away by them is more with increased weld times.


Available Models

Peak Secondary current (DC) Duty Cycle Power Factor Primary Voltage Secondary Voltage Cooling Medium
2500 amperes 7 % 1.00 440 Volt, three phase 7.5 Volt Air
6000 amperes 10 % 1.00 440 Volt, three phase 7.5 Volt Water
12000 amperes 10 % 1.00 440 Volt, three phase 15 Volt Water



Designed By - Rutuj Worth Concepts