Transformer Polarity | Subtractive vs Additive

Transformer Polarity | Subtractive vs Additive Transformer Polarity entails subtractive or additive. Polarity applies to single phase transformers. By IEEE, transformers rated 200kVA and below and winding voltage of 8660 volts and below shall have additive polarity. Polarity is typically shown with a dot mark. Polarity provides information on the direction the coils were wound and how the terminals are brought out to the tank cover.