Voltage detection in MV switchgear
March 2012
Electrical Power & Protection
Integrated voltage indicator with relay output.
The Vois R+ from Kries is an integrated capacitive voltage indicator according to the IEC 61243-5 standard for voltage detecting in medium voltage switchgear. The change from voltage present to voltage absent is indicated by a change in the arrow symbol on the front panel, from visible to invisible, and can also be monitored via the integrated relay outputs. The device needs no power supply to indicate the voltage, the energy necessary for indication is taken from the capacitive coupling and power is only required to drive the relay outputs.
The safety rules and laws dealing with working on medium voltage equipment and the five safety rules according to DIN -VDE 0105 have to be observed. Independent of the indication on the Vois R+, the earthing switch must be switched on before opening the switchgear or working on live parts. Vois R+ is suitable for connecting to specified capacitive coupling electrodes. The coupling part which is connected to Vois R+ must meet the interface conditions according to IEC 61243-5.
For testing voltages higher than 15 kV and frequencies lower than 16 2/3 Hz, the three-phase connecting point on the front has to be short circuited. The three-phase connecting point is adapted to the LRM conditions according to IEC 61243-5. The connecting point is suitable for testing phase comparison, phase sequence, redundancy, and as an option, maintenance testing. For this purpose Kries offers the universal CAP-Phase combined voltage detector and phase comparator.
Vois R + is suitable for use in an operating temperature range from -25 to +55°C and meets IP54 protection requirements.
For more information contact Johan van Staden, Surgetek, +27 (0)11 792 1303, [email protected], www.surgetek.co.za
Further reading:
Unpacking the technoeconomic case for cleaner power in wastewater plants
Schneider Electric South Africa
Electrical Power & Protection
Behind every reliable wastewater plant is an electrical system exposed to the effects of harmonics, voltage distortion and overloaded networks caused by fleets of variable speed drives on pumps and aerators.Together, they steadily drive up maintenance demands and elevate the risk of failure.
Read more...
Energy strategy as a competitive advantage for African businesses
Electrical Power & Protection
Energy is no longer simply something that businesses consume. When managed effectively, it becomes a controllable asset that supports resilience and efficiency and sets the foundation for long-term competitiveness.
Read more...
World’s fastest 14 bit arbitrary waveform generator
Vepac Electronics
Electrical Power & Protection
The ARB Rider AWG-700 from Vepac is the world’s fastest 14 bit arbitrary waveform generator, with a 20 GS/s real-time update rate and 14 bit vertical resolution.
Read more...
Transformers for mining house in Botswana
ACTOM Electrical Machines
Electrical Power & Protection
LH Marthinusen is completing the manufacture of two 30 MVA transformers for a mining house in Botswana.
Read more...
DIN-rail power supplies for reliable and efficient AC/DC conversion
Conical Technologies
Electrical Power & Protection
The Claf Power AD75-2BxxS series DIN-rail power supplies are designed for industrial automation, control systems and process environments.
Read more...
Rethinking power for Africa’s data centres
Schneider Electric South Africa
Electrical Power & Protection
Africa’s digital economy is scaling faster than its power systems. If it wants resilient, competitive and sustainable data centres, the starting point must be a grid-to-chip architecture rather than a genset-first mentality.
Read more...
The growing decentralisation of power grids
Electrical Power & Protection
The decentralisation of power generation is changing how national grids function. For electrical engineers, several new challenges and opportunities are on the horizon.
Read more...
Custom mini substations for Zambian copper mine
Electrical Power & Protection
Recent orders to supply seventeen specially engineered mini substations for an underground copper mine in Zambia reinforces Trafo Power Solution’s track record in delivering customised electrical solutons for challenging environments.
Read more...
Unifying building information into a sea of insight
Schneider Electric South Africa
Electrical Power & Protection
Facility managers realise that in order to gain the most from building automation, they can longer deploy and operate technologies in isolation. Modern, integrated building management solutions address this challenge by bringing data from multiple sources and dispersed locations like HVAC, lighting, access control, lifts, generators, field devices, energy and
Read more...
Smart power solutions for a low-carbon future
ABB South Africa
Electrical Power & Protection
As the world marked Earth Day 2026, ABB is highlighting the role of low-voltage smart power solutions in improving energy efficiency, reducing emissions and enabling more sustainable infrastructure.
Read more...
printer friendly version