MV Switchgears

Electronic Voltage Transformers, EVT Series

A compact and reliable replacement for traditional voltage transformers for 7.2–40.5 kV switchgear. Output 100 V/√3, load capacity 2 VA, optionally up to 15 VA, accuracy class 0.5 — full compatibility with existing measuring circuits.

Advantages of EVT Electronic Voltage Transformers

The electronic measuring principle improves the reliability and safety of 7.2–40.5 kV distribution networks
  • Ferroresonance Elimination
    The absence of a ferromagnetic circuit eliminates the possibility of ferroresonance phenomena — the main issue of traditional voltage transformers in networks with an isolated neutral.
  • Compact Design and Easy Installation
    The sensor is designed in the form factor of a Cable Connector Insulating Plug and is screwed directly into a cable connector according to IEC 50181, or is designed as a support insulator. No separate panel is required for installation. Installation takes only a few minutes.
  • Built-in 3U₀ Channel
    Each set includes a zero-sequence voltage measuring channel with accuracy class 1/3P. A separate zero-sequence voltage transformer is not required, saving space and cost.
  • High Measuring Accuracy
    Phase voltage accuracy class — 0.5. The phase displacement does not exceed 1°, compared with 3–10° for electromagnetic devices. Accurate measurement means reliable protection.
  • Operation in Harsh Conditions
    Operating temperature range: −40…+70°C, degree of protection IP65. Vacuum epoxy resin casting ensures durability and moisture protection.
  • Minimum Losses
    Power consumption is not more than 10 W, compared with 30–50 W no-load losses for a traditional VT. Over 15 years of operation, energy savings may reach up to 40%.
Designation Structure
EVT — XX X — XX — P
  • Series
    EVT
    Electronic Voltage Transformer
  • Voltage
    XX
    12 = 12 kV
    24 = 24 kV
    40.5 = 40.5 kV
  • Design type
    X

    C — Cable Connector Insulating Plug for interface C cable connector (GIS)


    D — support insulator (switchgear panels / cubicles)

  • Version
    XX

    01, 04, 08 — for C

    120, 210, 320 — for D


    P — with amplifier, 100 V

Examples of designations:
EVT-12C-01-P
EVT-24C-02-P
EVT-24D-210-P
EVT-40.5D-320-P

Technical Documentation by Series

EVT for GIS and switchgear panels / cubicles with solid insulation
EVT-C-P Series. Sensors in the form factor of a Cable Connector Insulating Plug for interface C cable connectors according to EN 50181
Technical characteristics
EVT for traditional switchgear panels / cubicles
EVT-D-P Series. Support insulators with integrated voltage sensor function
Technical characteristics