Circuit separation blocks MST-U

The separation blocks MSTU permit connection of electricity meters to the equipment without a necessity to disconnect voltage bridges between the voltage and current circuits of tested meters.


  • The MST-U bock is a passive separation transformer with identical balanced secondary windings;
  • The secondary windings are realized in order to suppress voltage differences among them;
  • The MST-U unit operates without external supply;
  • Simple assembly for new and old types of test equipments;
  • Design execution suppresses parasite mutual inductive linkage between individual secondary windings to maximum extend.

Technical data

Input voltage U1 230 V ± 20% (110, 220 V ± 20%, optional)
Frequency range 45 ... 65 Hz
Maximal amplitude deviation
among secondary voltages
Maximal power/position 10 VA (17 VA)
Maximal deviation UTi а U1
(between secondary and primary windings)
Maximal phase deviation 0,03°
Insulation strength UTi/U1
(between secondary and primary windings)
4 kV
Insulation strength among secondary windings 2,1 kV
Protection against short circuit