High and Medium Voltage Equipment
Equipment for substations, cable lines and distribution networks: bushings, measuring transformers, cable accessories, medium voltage switchgear and protection. We supply based on the network data and the specifications in the tender documents.
Insulators, cables, switchgear, protection and monitoring for substations and networks
Which product types do we supply?
- Bushings and Measuring TransformersBushings and current and voltage transformers for transformers, GIS and high voltage lines. · Power transformers in substations, Gas-insulated substations (GIS), Connection of generators to the grid, Metering and line protection
- Surge Arresters and InsulatorsMetal-oxide arresters and post or string insulators for protecting substations and lines. · Protection of power transformers, Cable terminations and medium voltage overhead lines, Substations and transformer stations, High voltage overhead lines
- Accessories for High and Medium Voltage CablesTerminations, joints, separable connectors and sheath link boxes for power cables. · Urban medium voltage cable networks, Connection of generating units to the grid, High voltage links to substations and GIS, Replacement of old paper-insulated sections
- Transformer Monitoring: DGA and Partial DischargeDissolved gas monitors, temperature probes, hydrogen sensors and partial discharge systems. · Power transformers in substations, Unit transformers in power plants and generation parks, Large distribution transformers and reactors, Medium voltage equipment in the cubicle
- Medium Voltage Switchgear and ReclosersCubicles and ring main units, load break switches, vacuum circuit breakers, reclosers and fault indicators. · MV/LV transformer stations, Urban and rural distribution networks, Medium voltage overhead lines, Connection of industrial consumers and generating units
- Protection, Automation and Testing for SubstationsProtection relays, substation automation, time reference, teleprotection and test sets. · Transformer substations and switching stations, Protection of generators and transformers, Dispatching and remote control (SCADA), Commissioning and maintenance of protection systems
- Electrical Insulating Materials for Transformers and Electrical MachinesInsulating paper and board, pressboard, laminates, films and insulating tapes for transformers and electrical machines · Power and distribution transformers, Electric motors and generators, Coils, reactors and dry-type transformers, Winding and winding-repair workshops
Which brands do we quote in this category?
- Arbiter Systems
- Arcteq
- Arteche
- b2 electronics
- BBC Cellpack
- Beckwith Electric
- Beijing Sifang Automation
- Brugg Cables
- Cahors
- Camlin Energy
- Cogebi
- Conprove
- Cottrell Paper Company
- CROXS
- Driescher
- Dynamic Ratings
- Efacec
- Ellis Patents
- EMT Global
- Enervac International
- Entec Electric & Electronic
- ERLPhase Power Technologies
- Fivestar HV
- FJINNO
- G&W Electric
- GE Vernova (Grid Solutions)
- H2scan
- HIGHVOLT Prüftechnik Dresden
- Hitachi Energy
- hopf Elektronik
- Horstmann
- HSP Hochspannungsgeräte
- HUAC
- Hughes Power System
- Ingeteam
- IPEC
- ISOVOLTA
- Kalkitech
- Kingsine Electric Automation
- KONČAR Instrument Transformers
And more brands on request: send us the code or the nameplate of the item.
Spare parts and accessories
- Short-circuit-tested cable cleats
- Link boxes and voltage limiters for sheaths
- Separable connectors and cable ends for cubicles
- Fault indicators for cables and overhead lines
- Discharge counters and leakage current indicators
- Fibre-optic temperature probes and transformer thermometers
- Board, paper and insulation parts for transformers
What we do for you
- Selection according to the network and installation data
- Identification of parts by rating plate or drawing
- Data sheets and, on request, conformity documents
- Consultancy on replacing equipment in existing substations
- Quotations compliant with the tender specifications in public procurement
Frequently asked questions
What do medium voltage and high voltage mean in electrical installations?
In common use, medium voltage means networks of 6, 10, 20 or 30 kV, and high voltage those of 110, 220 or 400 kV. The limits differ between documents: IEC switchgear standards call any value above 1 kV “high voltage”, and medium voltage cubicles are usually treated up to 52 kV. For this reason, state the rated voltage and the maximum voltage of the equipment in your request. We cover both ranges, from cubicles and transformer stations to bushings, measuring transformers and cable accessories for high voltage substations.
What details should I send for a quotation on substation equipment?
The main data are the rated and maximum voltage, the rated current, the short-circuit current with its duration, the type of installation (indoor or outdoor) and the standard required, usually IEC. Add the product code or a photograph of the rating plate if you are replacing existing equipment, together with the drawing with the mounting dimensions. For insulators and arresters the pollution level is also given, and for protection the diagram and communication protocols. With these data the quotation can be prepared without further questions, and if any information is missing we tell you exactly what needs to be completed before establishing the configuration.
How do I choose between oil-impregnated paper and resin bushings?
Oil-impregnated paper (OIP) versions have a long track record in service and are common on existing transformers. Resin-impregnated paper (RIP) versions contain no oil in the insulating body, which reduces the risk of leakage and fire and allows installation in varied positions. The choice depends on the interface with the transformer, the mounting position, the operator's policy and the voltage and current data. For a replacement, the flange dimensions decide compatibility more than the insulation technology. Send the rating plate of the existing unit and, if possible, the mounting drawing, so that we can check the fit before ordering.
How long does delivery of high and medium voltage equipment take?
The lead time is 24–72 h when the item is available locally or at the supplier; this applies mainly to small parts and standard accessories. For equipment configured to specification, such as measuring transformers, cubicles or relays with settings, delivery is to order, usually 1–4 weeks, and depending on the brand and the specifications it may take longer. In the quotation we state the lead time for the configuration requested, so that you can plan the outage and the work in the substation. If you have a contractual deadline or a maintenance window, mention it in the request and we will confirm what can be met.
Do you prepare quotations for public procurement, based on the tender specifications?
Yes. We can prepare the quotation starting from the requirements in the tender specifications: voltages, standards, accuracy classes, test reports and the conformity documents required by the contracting authority. Send us the technical extract or the list of items, with the CPV codes and quantities, and we will reply with data sheets and delivery times. If a product cannot meet a requirement, we tell you so from the start, to avoid non-conformities when the bid is submitted. For items with several accepted variants, we propose equivalent alternatives, with data compared point by point against the original requirement.
How do I replace old equipment in a substation when I no longer have the documentation?
We start from the rating plate, which gives the voltage, current, year and type, and from photographs and dimensions of the mounting part. For bushings the flange, length and terminals matter, for measuring transformers the ratios and classes, and for switchgear the dimensions of the bay. Sometimes mechanical adaptations or recalculation of the protection settings are needed, so we compare the data before ordering. Do not estimate from memory the dimensions of equipment in the substation. If access to the plate is difficult, a clear photograph of the equipment and of the mounting area helps with identification.
Request a quotation
Send the codes, the nameplate photo or your parts list; we reply in English with availability and the lead time written in the quotation.
Request a quoteUpdated: 2026-11-12