Current instrument supporting transformer CTSO 38

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 5-2500 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, 0.2S, 0.5, 0.5S, 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.

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 5-2500 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, 0.2S, 0.5, 0.5S, 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 (See “The Instructions for the mounting and operation”).

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 and according to the parameters.

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.

Transformers are fixed by the means of four screws M12 in the holes in the basic frame. We recommend use terminal ends corresponding to the used cross-section of the conductor for attaching to the secondary outlets. The secondary terminal plate is equipped with the waterproof cover. The cover can be sealed. Inside, there is the set with jumpers and small screws for the possibility of earth connection and short circuiting of the wiring. (See “The Instructions for the mounting and operation”.)

In cases where the substitution for the older types of transformers (various producers) is required, we supply transformers CTSO 38 with modified basic plates that have identical mounting spacing to spacing of the substituted types.

Creepage length 1257 mm (comply with pollution degree IV i.e. 31 mm/kV for insulation voltage 38.5 kV).

Current instrument transformers CTSO 38 complied all the tests according to the IEC 61869-1, IEC 61869-2, IEC 60060-1, GOST 15150, GOST 1516.3-96, GOST 7746-2001.

As a part of customer service we may arrange an official calibration of the transformers carried out by official calibration bodies, including the issue of corresponding calibration protocols.

In agreement with the customer the parameters of the transformer may be modified according to the client´s particular wishes. 

Highest voltage for equipment: 36/38.5 kV
Power frequency test voltage: 70/80 kV
Lightning impulse test voltage: 170/180 kV
Nominal primary current: 5 - 2500 A
Nominal secondary current: 5 A or 1 A
Rated short-time thermal current, Ith: max 80 kA/1s (31.5 kA/3s)
Rated dynamic current, Idyn: max 200 kA
Rated continuous thermal current, Icth: 120 % In
Accuracy class - measurement: 0.2S, 0.2, 0.5S, 0.5, 1, 3
Overcurrent factor - measurement: FS 5, FS 10
Accuracy class - protection: 5P, 10P, PX
Overcurrent factor - protection: 5, 10, 15, 20, 25, 30
Nominal power: 5 - 60 VA
Nominal frequency: 50 Hz
Length creepage: 1257 mm
Weight: 60 kg
Thermal insulation class: E
Operation conditions: 

operating temperature from -40 to + 40 °C

corresponds to temperature class -40 / 40 according to IEC 61869-1

Standard: IEC 61869-1, IEC 61869-2, IEC 60060-1, GOST 15 150, GOST 1516.3-96, GOST 7746-2001