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Welder upgrade improves THDI

EFD Induction has announced that its lower-power Weldac welders will feature an optionfor a 12-pulse diode rectifier. Previously, lower power Weldacs featured a 6-pulse rectifier.



The new option has been shown to help reduce typical total harmonic distortion in current (THDI) from 25-30 per cent to approximately 11 per cent. The issue of harmonic distortion, or ‘harmonics’ as it is commonly called, is a growing cause of concern for power utilities and power systems managers.


The proliferation of non-linear loads causes disturbances that impair equipment performance and affect total voltage supply.The new 12-pulse diode rectifier is available up to 550kW. An auto-transformer can be supplied if required, and an additional small external harmonic filter can also be installed in order to meet guidelines set by the Institute of Electrical and Electronics Engineers.


EFD Induction solid-state Weldac welders offer high total efficiency measured from the mains inlet to the weld coil. This efficiency, together with the new 12-pulse diode rectifier,helps minimise power and cooling-water consumption.The new 12-pulse diode rectifier is available in single cabinet Weldacs with power outputs up to 550kW. EFD Induction’s high-power Weldac systems already offer the option of a 12-pulse rectifier.   


Weldac 300 


EFD Induction’s smaller solid-state Weldac welders now have the option of a 12-pulse diode rectifier