Taps on all units for adjustments to incoming source voltageFull capacity secondary neutral as required by the National Electric CodeShielding attenuates line to ground noiseIsolation minimizes load disturbances caused by the SCR driveA transformer is needed to magnetically isolate the incoming line from the motor driveThe transformer must also provide a voltage change to match the required voltage of the SCR driveStandard designs are delta primary and wye secondary to match the common power sources required in most three phase rectifier circuitsDesigned to handle the mechanical stresses, voltage demands and harmonics associated with SCR applications