• Power Engineers and Consultants

Electroplating Rectifier

Power Engineers & Consultants is well known rolling contact type automatic voltage controllers, electroplating and chemical process rectifiers and special purpose transformers. The company offers an electroplating rectifier to ensure constant voltage to the consumer, as the electricity supply is often erratic, and load pattern irregular. This affects electrical motors (particularly smaller capacity motors up to 7.5 HP). Specifications: input voltage ? 380-440 V, 3-phase 50 Hz AC supply; output voltage ? fixed rated maximum DC voltage or variable from zero to maximum rated voltage; output current ? rated maximum DC current; temperature rise ? less then 35?C above ambient at the top of the oil; efficiency ? 12 V rectifier ? 82%, 24 V rectifier ? 90% 100 V rectifier ? 94%, 200 V rectifier ? 96%, and more than 250 V, rectifier ? more than 97%; ripple content ? less than 5%; and insulation - `A? class for oil cooled. Why the regulator control is superior to thyristorised control in rectifier: in plating application the regulator is better and technology is adopted in Germany and Europe because of as explained above; other manufacturers of rectifiers have shifted to thyristors because they have to use sliding carbon brush type regulators; manufacturers of rectifiers claim that thyristor controlled rectifier has less losses than regulator. They compare thyristor with sliding carbon type regulator. In this case their claim is not true. The company uses vertical coil type rolling carbon regulator. The copper section is three times so the losses are almost 1/6 or 20%; in the regulator the roller moves on both sides of the coil to give ?440 V or ?254 V output. The rectifier is designed in `Q? connection in which the regulator current is half the line current so losses are less and life is much more.