MV Switchgears

Voltage display EVI-S2

Rated voltage 7.2–40.5 kV. Provides local voltage status indication, remote signaling via relay outputs and an analog signal output (3–30 V) on the system plug for connection to a process control system.
  • LCD Indication
    Clear three-phase indication on the display
  • System Plug
    Direct connection to telemechanics
  • Relay Outputs
    Voltage transformer replacement
  • 4 Setting Stages
    Universal capacitance module

Where EVI-S2 Is Used

The device goes beyond conventional indication — it is a full-featured measuring and signaling unit for a digital substation
Voltage Monitoring
Continuous three-phase monitoring with information shown on the LCD display. Relay outputs transmit a voltage presence/absence signal to process control and SCADA systems. Response time ≤ 1 sec.
Phasing and Synchronization
Built-in test sockets for connecting a phase sequence indicator or phase comparator. Phase sequence checking and synchronization of parallel sources without additional equipment.
Analog Output
3–30 V
Linear proportional signal on the system plug, directly proportional to the voltage on the HV side. Connection to analog input modules of process control systems, SCADA systems, and automatic transfer controllers with restoration of normal operation without additional converters.
Automatic Transfer System with Restoration of Normal Operation, Undervoltage Protection
Voltage signal source for automatic transfer systems with restoration of normal operation and undervoltage protection systems. In case of voltage loss, switching to the reserve source is performed; when voltage returns, the original scheme is restored automatically.

Direct Connection to Telemechanics

The EVI-S2 system plug outputs an analog signal of 3–30 V, linearly proportional to the voltage on the high-voltage side. This allows the device to be used as a full-featured voltage sensor in process control and SCADA systems — without a voltage transformer or intermediate converters
  • Compatibility with 0–10 V and 4–20 mA analog input modules
  • Direct data transmission to automatic transfer controllers with restoration of normal operation
  • Voltage archiving for power quality analysis
  • Scaling for any controller input range
  • Analog Output 3–30 V
    Linear proportional signal on the system plug, directly proportional to the voltage on the high-voltage side. Compatible with most controller analog input modules
  • Two Relay Outputs
    Type 2: independent Relay1 and Relay2 contacts for remote signaling of voltage presence/absence. Response time ≤ 1 sec
  • No Special Cables
    No coaxial cables are required for connection to capacitive dividers and the telemechanics system — standard signal wiring is sufficient
  • Self-Powered Indication
    The main LCD indication does not require auxiliary power supply — the device is powered by the capacitive divider. 24–230 V power supply is required only for the relays.
Replaces a Conventional Voltage Transformer
EVI-S2 with relay outputs and a system plug can fully replace a VT in automatic transfer systems with restoration of normal operation and undervoltage protection systems. Direct connection to telemechanics controllers without intermediate converters.
  • No special coaxial cables — standard signal wiring is sufficient
  • No separate intermediate relays or converters
  • System plug for direct connection to analog signal input modules

EVI-S2 vs Conventional Voltage Displays

Why S2 is not just “another display unit”, but a new generation
Parameter EVI-1…EVI-4 Conventional Series EVI-S2
Indication type ×LEDs ✓LCD display
Relay outputs ×EVI-R only, 1 group ✓2 groups, type 2
Capacitance setting ×Fixed ✓4 stages, 9 switches
Connection to telemechanics ×No ✓System plug
Self-test ×No ✓Built-in “Test” button
Application in automatic transfer systems with restoration of normal operation and undervoltage protection ×Limited ✓Full-featured
U0 monitoring for earth-fault protection ×No ✓Yes
Remote monitoring ×No ✓Via relay outputs
Indication type
EVI-1…EVI-4 Conventional Series
×LEDs
EVI-S2
✓LCD display
Relay outputs
EVI-1…EVI-4 Conventional Series
×EVI-R only, 1 group
EVI-S2
✓2 groups, type 2
Capacitance setting
EVI-1…EVI-4 Conventional Series
×Fixed
EVI-S2
✓4 stages, 9 switches
Connection to telemechanics
EVI-1…EVI-4 Conventional Series
×No
EVI-S2
✓System plug
Self-test
EVI-1…EVI-4 Conventional Series
×No
EVI-S2
✓Built-in “Test” button
Application in automatic transfer systems with restoration of normal operation and undervoltage protection
EVI-1…EVI-4 Conventional Series
×Limited
EVI-S2
✓Full-featured
U0 monitoring for earth-fault protection
EVI-1…EVI-4 Conventional Series
×No
EVI-S2
✓Yes
Remote monitoring
EVI-1…EVI-4 Conventional Series
×No
EVI-S2
✓Via relay outputs
Technical Characteristics
Full data for design and operation
  • 7.2–40.5 kV
    Rated voltage
  • 50/60 Hz
    Frequency
  • IP54
    Degree of protection
  • AC/DC 24–230 V
    Auxiliary power supply, type 2
  • 2.5 VA
    Power consumption
  • 250 V AC, 5 A / 30 V DC, 5 A
    Relay contacts
  • ≤ 1 sec
    Relay response time
  • from –25°C to +40°C
    Operating temperature

Signal Indication

No. Status Condition LCD
Indication		 Note
1 No voltage U < 10% Un No indication, type 1. Active zero, if auxiliary voltage is available — type 2 only
2 Voltage
present 1		 10% Un ≤ U ≤ 45% Un Continuous indication
3 Voltage
present 2		 U > 45% Un Continuous indication
4 Function
test passed		 Test button pressed, no failures, indication normal Momentary indication
No.
1
Status
No voltage
Condition
U < 10% Un
LCD
Indication
Note
No indication, type 1. Active zero, if auxiliary voltage is available — type 2 only
No.
2
Status
Voltage present 1
Condition
10% Un ≤ U ≤ 45% Un
LCD
Indication
Note
Continuous indication
No.
3
Status
Voltage present 2
Condition
U > 45% Un
LCD
Indication
Note
Continuous indication
No.
4
Status
Function test passed
Condition
Test button pressed, no failures, indication normal
LCD
Indication
Note
Momentary indication

Indication Range According to IEC Standard

0
No voltage
No indication
10% UN
Transition zone
Permitted zone between voltage absence and voltage presence
45% UN
Energized
Voltage presence indication
58% UN
= UN / √3
Energized
Criterion met for repeated testing
1.2 × UN / √3
UN
Energized
Overvoltage zone
0–10% UN
10–45% UN
45–58% UN
58% UN — 1.2 × UN / √3
1.2 × UN / √3 — UN
0–10% UN
no voltage
No voltage zone
No indication.
10–45% UN
transition
Transition zone
Permitted intermediate range.
45–58% UN
energized
Voltage presence zone
Voltage presence indication.
58% UN = UN / √3
test point
Energized
Criterion met for repeated testing.
58% UN — 1.2 × UN / √3
operating
Energized zone
Operating indication range.
1.2 × UN / √3 — UN
overvoltage
Overvoltage zone
Voltage above the repeated-test criterion.