What is the primary function of a Potential Transformer (P.T.)?

The primary function of a Potential Transformer (P.T.) is to convert high voltage to a usable level for protection and metering. This essential role allows for the accurate measurement of high voltage levels in electrical systems without exposing sensitive equipment or operators to dangerous voltages.

Potential Transformers work by reducing the voltage to a lower, safer level that can be easily measured by standard metering equipment or used in protective relaying systems. By providing a scaled-down version of the high voltage, they ensure that the monitoring and control systems can operate effectively and safely.

This function is crucial in substations and electrical distribution networks, as it enables the safe operation of devices that require voltage measurements for operational or safety purposes. Other options, such as stepping up voltage or measuring gas moisture content, do not align with the fundamental purpose of a P.T. Moreover, providing backup power during outages relates more to uninterruptible power systems and does not pertain to the function of monitoring voltage levels.