What type of polarity do any transformer 200 kVA or smaller with primary voltage under 8,660 volts have?

Transformers that are 200 kVA or smaller with a primary voltage under 8,660 volts typically exhibit additive polarity. Additive polarity means that when the primary and secondary windings are connected in phase, the voltages add together, which is essential for proper operation in many electrical systems.

This type of polarity is common in smaller transformers because it simplifies the design and installation processes, particularly in three-phase systems, where aligning the phase relationships is critical for effective performance. Essentially, when transformers of this size are wired correctly, they ensure that the voltages from the primary and secondary windings reinforce each other, allowing for efficient energy transfer.

Understanding the characteristics of transformer polarity is essential for linemen and electrical technicians, as it directly relates to the safe and efficient operation of electrical systems.