Current instrument supporting transformer CTSO 38 is designed for measurement and protection of high voltage distributing equipment for outdoor design for nominal primary currents of 5-1250 A and for the highest voltage of system of 38.5 kV.
The value of secondary current is 5 A or 1 A with the possibility of combination. The accuracy classes for the circuits of measurement are 0.2, 0.5, 1, 3, for the circuits of protection are 5P, 10P. The transformers fulfill the required accuracy class at intervals from 25 % to 100 % of rated load. The terminal working current is 120 % IN, in case of the agreement of the producer and the customer it is possible to deliver also the other values, for example 200% IN.
Transformers CTSO 38 are constructed as transformers with single-turn or multi-turn primary winding. The up- -to-date construction of these transformers allows the switching not only on the secondary side, but also on the primary side. The advantage of the primary switching is the easy mounting by the means of connecting two jumpers into the circuit by the means of screws M8 (both the screws and jumpers are the parts of the transformer).
The secondary winding is wound on the magnetic core made of directed magnetic materials, eventually made of the alloy of nickel, iron and copper "permalloy". The maximum number of cores can be from 1 to 3 according to the request of customer.
All active parts of transformers CTSO 38 are compound-insulated with epoxy-mixture resistant to the external effects (UV radiation, humidity, etc.) This material performs both the electrical insulating and the mechanical functions.