Voltage & Current Sensor
We provide Voltage Sensor, Current Sensor and Grid Intelligent Monitoring unit from Zelisko. They are majority used in ABB RMU, Siemens RMU, Schneider RMU in Thailand. With this sensor and monitoring unit, there is no need for the conventional big block type voltage transformer and/or big ring type current tranformer (the more burden required, the bigger the unit is). This Voltage & Current Sensor with grid intelligent monitor for medium voltage system, therefore, are very compact and useful for remote monitoring in Smart Grid of MEA and PEA.
Voltage Sensor
The voltage sensor is specially designed to connect at the back of the plug in Tee connector that connected to the bushing of the ringmain unit. It has to be specified with the required primary voltage that is the same as operating voltage of the ringmain unit. The secondary voltage, burden and impedance shall be matched with the monitoring unit. Zelisko also provide Grid Intelligent Monitoring unit namely GIM. Below is the specification of Voltage Sensor
Model: SMVS – UW1001, SMVS – UW1002-0, SMVS – UW1002-1 & SMVS – UW1002-2
Insulation level | max. 36 / 70 / 170 kV |
Rated frequency | 50 Hz / 60 Hz |
Rated voltages | max. 30/√3 kV |
Voltage factor | 1,2 Un and 1 9 Un 8h |
Accuracy class / Protection class | 0,5 / 1 / 3 // 3P / 6P |
Rated secondary voltage | 3,25/√3 V (or on request) |
Standard | IEC60044-7 |
External conditions | Operation: -25°C to +55°C or -40°C to +40°C * |
Storage: -40°C to +80°C (or on request) | |
Rated burden | 200kΩ +1% Genauigkeit, 350 pF +10% * this value is for Zelisko GIM |
Overvoltage protection | Internal surge arrester |
Cable connector type | UW1002-3: Euromold K480TB |
UW1001: Euromold K440TB, K400TB |
Current Sensor
The current sensor is simply a window or ring type current transformer but with small burden. Only small current shall be fed to the Grid Intelligent monitor unit. It has to be specified with the required primary current designed by the feeder load. The secondary current, burden and impedance shall be matched with the monitoring unit. THis current sensor can be a fix window or a split window type. With the split window, there is no worry about the size of the Tee conector. Zelisko also provide Grid Intelligent Monitoring unit namely GIM. Below is the specification of Current Sensor.
Model: SMCS/T – JW1002 & SMCS – JW1001
Insulation level | 0,72 / 3 kV |
Rated frequency | 50 Hz / 60 Hz |
Rated short time thermal current | 25 kA / 1 s |
Primary current | 300 A; Ext. 200% * |
Accuracy class | 1&5P10…5P20 |
Output signal | 225 mV according to IEC 60044-8 |
Standard | IEC 60044-8 |
External conditions | Operation: -25°C to +55°C or -40°C to +40°C |
Storage: -40°C to +80°C, on request | |
Rated burden | ≥ 20 kΩ |
Grid Intelligent Monitor
As we call it Grid Intelligent Monitor, it is a Digital short-circuit and ground fault indicator with measuring function. it is a smart device that get input from the corresponding voltage sensor and corresponding current sensor. it offers a complate portfolio for network monitoring, power quality recording, fault recording, phasor measurement. it is designed for Zelisko low-power sensor technology in accordance with IEC 60044. It is optionally be with Modbus RTU interface. Below is the specification;
Communication: | Auxiliary voltage: |
Interface RS485 incl. Modbus RTU communication for all data and remote configuration | AC 230 V, DC 24 – 110 V Battery with service life > 15 years |
Signalization: | Inputs: |
Display for visualization of current measured values or fault information in the distribution network, 4 function keys 3 LEDs to signal the operating mode 2 binary outputs | 3 inputs from Zelisko Voltage sensor 3 inputs from Zelisko Current sensor |
Measured variables: | Housing: |
RMS measured values Phase voltages and currents, ground current, power system frequency and cos φ phase angle, active power, reactive power and apparent power Energy meters Minimum and maximum values for all phase currents from 15 minutes to one year as a slave pointer function | Polycarbonate, for panel flush mounting Dimensions: 96 x 48 x 109.5 mm (W / H / D) Protection class: Front IP40, rear IP20 |
Time synchronization: | Temperature range: |
Time synchronization via Modus RTU | From -40 °C to +70 °C |
Voltage Amplifier
In the case we need voltage signals for voltage relay such as Under Voltage, Over Voltage relay or Frequency protection relay, we can use a combination of the above Voltage Sensor and connect the voltage signal to Voltage Amplifier and can get the required voltage in the same format as a secondary voltage of Voltage Transformer, for example, 110V/sqrt.3 with burden of 1VA and class 0.5/3P.
This arrangement can reduce the cost and installation area from the conventional way of adding one panel of voltage transformers.
Zelisko provides Voltage Amplifier model VMA-X2 (new model as of September 2024) with the following characteristic;
Inputs |
Up to 3 inputs for Zelisko voltage sensors According to IEC 61689-11 |
Maximum input voltage of 120% *Ur (3 phases) Maximum input voltage of 190% *Ur (2 phases, earth fault) |
Outputs |
Up to 3 outputs for AC Voltage Pre-configured to 100/√3 V Max. load 1 VA per channel |
Auxiliary supply |
Auxiliary supply voltage DC 24 V ±10% |
Power consumption 5 W (max. 15 W) |
Notifications |
1 LED signals system operation (Green: Ok) |
1 LED signals system failure (Red: Error) |
Accuracy |
Up to IEC 61869-11 accuracy class 0,5 |
Housing |
Aluminium housing for mounting on DIN rails |
Dimensions (W / H / D) 190 x 110 x 50 mm |