Measuring current transformers SMTSM (hereinafter referred to as transformers) are designed to transmit measurement information signals to measuring instruments, protection devices, automation, signaling and control in AC networks with a frequency of 50 or 60 Hz.

Measuring current transformers SMTSM are designed for outdoor installation.

The current transformers have a cast housing made of epoxy compound by injection molding.

The insulation material of the current transformers has excellent arc, ozone and UV protection characteristics, while having high mechanical strength. The creepage distance and discharge distance of SMTSM current transformers are designed for high levels of air pollution.


  • Rated voltage up to 42 kV
  • Rated current up to 4000 A
  • Rated thermal current up to 40 kA
  • Number of secondary windings from 1 to 5
  • Winding accuracy class for measurement 0.2; 0.2S; 0.5; 0.5S; 1; 3;
  • Winding accuracy class for protection 5P,10P;
  • Switching ratio of transformation in the ratio 1:2 on primary or secondary conclusions.
  • Ambient conditions: temperature from -60° to +55°.


  • Lack of any maintenance throughout the entire period of operation
  • Fireproof design
  • Possibility of installation in any plane
  • High loads for all accuracy classes
  • Low partial discharge (PD)
  • Resistance to aggressive environmental conditions
  • The hydrophobic material exhibits excellent outdoor performance and also minimizes the possibility of arcing.
  • No ozone depleting gases

Due to the fact that current transformers of the SMTSM series were developed for operation at high overloads, their application has widely proven itself in traction substations of railways, in hard-to-reach facilities where no equipment maintenance is required, in enterprises with high pollution and difficult operating conditions for electrical equipment.

Transformers meet the requirements of IEC, ANSI, IEEE, GOST standards

Measuring current transformers SMTSM are a good alternative to obsolete and obsolete measuring current transformers with oil insulation.