Сurrent transformers bus-bar type ТШЛ-20 (TSHL-20)

Сurrent transformers bus-bar type ТШЛ-20 (TSHL-10)

Current transformer TSHL-20Description

The transformers are intended for embedding in phase-shielded conduction for the rated voltage of 20 kV. The transformers are intended for transmitting the measuring information signal to measuring instruments and to protection, automatic control and signaling devices as well as for insulation of secondary circuits from high voltage in alternate current electric appliances with 50 or 60 Hz frequency .
The transformers for differential protection are manufactured at the special order.
The transformers are manufactured in climatic versions "YXL" (temperate outside mounting) and "Т" (tropical) according to the standard requirements of GOST 15150 location category 2 and are intended for usage under the appropriate operating conditions.

Bus bar is to be connected compulsory to transformer's tapping with "Ш" marking.

Transformer's body has 4 grooves with diameter of 32 mm to fix in gutter box of transformer flange.

Transformers are supplied with protective transparent covers for separate sealing of secondary winding's tappings (example of sealing)

The transformer is patented
Patent Certificate 6271, Priority certificate №99500410 from 12.05.99. 

Sometimes one can experience lack of space and, there is no possibility to increase it, to shield each phase of current-currying bus-bars and to  keep irequired minimal distances between neighbouring phases and distance to closest bus-bar. This leads to increased influence of neighbouring current-currying busbars on transformation of primary current in transformers with high accuracy class and leads tto the transformer failing to stay in a given accuracy class.

In order to avoid this situation a special technology was used to manufacture secondary windings of transformers TSHL-20-I, which allows to nulify influence  of neighbouring current-currying bus-bars and curves of own bus-bar. Also this transformers may be mounted into nonshielded electrical pathway.

The order on such transformer should include code "E" (shielded winding).
For example:

Picture 1 shows minimal distances required for normal TSHL-20-1. Picture 2 shows minimal distances required for TSHL-20-1 with shielded winding.


Table 1. Technical data


Normal value

Rated voltage, kV
Maximum operating voltage, kV 24
Rated frequency of AC current, Hz 50 or 60
Rated primary current, A
3000; 4000; 5000; 6000; 8000; 10000; 12000; 14000; 15000; 16000; 18000
Rated secondary current, A
1; 5
Number of secondary winding
2 or 3

Accuracy class:
- of secondary winding for measurement
- of secondary winding for protection

0,2; 0,2S; 0,5; 0,5S; 5Р; 10Р
5Р; 10Р
Rated secondary burden at power coefficient cos φ= 0,8, VA
- of secondary winding for measurement
- of secondary winding for protection

Short-circuit current ratio of secondary windings for protection, no less:
- for accuracy class 10P, at a given primary current, A:
  5000; 6000
- for accuracy class 5P, at a given primary current, A:
  6000; 8000; 10000
  12000; 14000; 15000; 16000; 18000


Three-second dynamic current, kA:
at a given primary current, A:
- 6000;8000;10000
- 12000;14000;15000;16000;18000

Test voltage, kV:
- of industrial frequency during one minute
- of full lighting impulse


*) should be specified in the order

Table 2. Dimensions

Rated primary current, A Dimensions, mm Weight, kg, max
D D1 D2 H H1 h L b1 b2

3000; 4000; 5000;
6000; 8000;10000

520 300 351 420 180 25 350 140 180 105


680 430 481 390 150






14000; 15000;
16000; 18000

830 555 606



General view of transformer (drawing)