ABB TPU 70.43

Indoor supporting current transformer

The transformers are cast in epoxy resin and designed for insulation voltages from 36 kV to 40.5 kV. The transformers are designed as single-or-multiple turn transformers, with one transformer ratio, or with the possibility to be switched over on the secondary or primary side.

The number of secondary windings are from 1 to 8 (usually 2 secondary windings), depending on the combination of parameters (such as the accuracy class, shortcircuit current, overcurrent factor…). The secondary windings are used for measurement or protection purposes, or for special use (testing winding, „PX“ class windings ..). One terminal of each secondary winding used and one terminal of short-circuited and not used winding have to be earthed during the transformer operation.