Why the vt must be earthed on the primary side?

The voltage transformer (VT) must be earthed on the primary side to ensure safety and stability in the electrical system. Earthing helps prevent overvoltages and provides a reference point for the system, reducing the risk of electrical shock and equipment damage. It also helps in fault detection and protection by ensuring that any fault currents have a clear path to ground, facilitating the operation of protective devices. Additionally, proper earthing minimizes electromagnetic interference and enhances the reliability of measurements taken from the VT.