An electrostatic shield for controlling the electrostatic field between a high voltage conductor and a low voltage conductor in an instrument transformer is provided. The instrument transformer has a current transformer and a voltage transformer. The current transformer has a split core which includes a first core segment and a second core segment. When the first core segment adjoins the second core segment, a current transformer is formed, having a core formed from the first and second core segments. The high voltage conductor runs between the first and second core segments of the current transformer. The first core segment is encapsulated in a polymer resin and when encapsulated, forms a first encasement. The second core segment has a low voltage winding mounted thereon. The electrostatic shield is disposed between the low voltage winding and the high voltage conductor. A second encasement is formed by encapsulating the electrostatic shield, low voltage winding and second core segment in a polymer resin.