What is a medium-voltage electrical service connection?
A medium-voltage electrical service connection is the connection point between the distribution grid (13.2 kV or 22.8 kV, depending on the utility) and a customer's facility whose consumption level cannot be efficiently served at low voltage (120/240 V). Unlike a small residential or commercial service, a medium-voltage connection delivers power before it is stepped down, so the customer must provide its own distribution transformer.
In practice, this means the company shifts from buying electricity that is already usable, to buying it at medium voltage and stepping it down internally. That shift brings technical and economic advantages, but also new regulatory responsibilities.
When does your company need a medium-voltage connection?
Not every industrial business requires medium voltage. The utility typically requires — or recommends — it in these scenarios:
- Contracted demand exceeds roughly 50-100 kW, depending on the low-voltage network capacity in the area
- The plant has large motors or loads with heavy starting currents that cause voltage dips on the local low-voltage network
- A growth plan will make the current connection insufficient within 1-2 years
- The site is far from the nearest distribution transformer, so a low-voltage connection would mean excessive losses
- Higher reliability and power quality are required (industrial parks, continuous-process plants)
Components of a medium-voltage service connection
A medium-voltage connection project is not just a cable: it's a full system that must comply with NEC standards and the utility's technical requirements.
| Component | Function |
|---|---|
| Delivery point | Boundary between the utility's network and the customer's installation |
| Disconnect switch | Allows the installation to be isolated for safe maintenance |
| Medium-voltage metering cell | Measures consumption directly at 13.2 kV or 22.8 kV |
| Distribution transformer | Steps medium voltage down to 220/440 V for internal use |
| Protection (cut-outs, relays, surge arresters) | Guards against overcurrent, faults, and lightning surges |
| System grounding | Ensures safety in the event of faults or electrical discharges |
| Cabling (overhead or underground) | Carries power from the grid to the transformer |
The utility approval process
Installing a medium-voltage service connection in Ecuador is not something you can execute without prior authorization. The typical process with the utility (CNEL, Empresa Eléctrica Quito, EEASA, or another, depending on the province) follows these steps:
- Application and feasibility study — The utility evaluates whether the nearby network can deliver the requested load
- Electrical design — A qualified electrical engineer prepares drawings that comply with NEC standards and the utility's requirements
- Plan approval — The utility reviews and approves the design before construction begins
- Construction and installation — Civil and electrical works are executed: structure, transformer, cell, and protection
- Technical inspection — The utility verifies the work matches what was approved
- Energization — Once the inspection passes, the system is energized and the final meter installed
How much does a medium-voltage service connection cost in Ecuador?
Cost depends mainly on transformer capacity, distance to the existing network, and whether the run is overhead or underground (more expensive, but safer and more aesthetic).
| Transformer capacity | Typical application | Estimated installed price (Ecuador) |
|---|---|---|
| 50 – 100 kVA | Small industry, large workshops | From USD 6,000 depending on distance to the grid and line type |
| 100 – 250 kVA | Mid-size companies, small shopping centers | From USD 12,000 depending on distance to the grid and line type |
| 250 – 500 kVA | Mid-size industrial plants | From USD 25,000 depending on distance to the grid and line type |
| 500 kVA – 1 MVA | Large industrial plants | From USD 45,000 depending on distance to the grid and line type |
These figures include the study, design, transformer, medium-voltage cell, protection, and civil and electrical installation. They do not include the utility's own service-connection charges, which are billed separately per its current tariff schedule.
For an estimate based on your project's capacity and location, use our electrical project quote tool.
Common mistakes when planning a medium-voltage connection
- Undersizing the transformer by planning only for current load instead of 5-10 year growth
- Skipping the feasibility study before purchasing equipment, risking that the network can't support the requested load
- Poor grounding, which compromises personnel safety and correct protection operation
- Not budgeting for maintenance of the transformer and medium-voltage cell, which require periodic inspection
Frequently Asked Questions
Ecuadorian utilities (CNEL, Empresa Eléctrica Quito, EEASA, and others) typically operate at 13.2 kV or 22.8 kV, depending on the concession area. The exact level is confirmed by your local utility's feasibility study.
Need to design or install a medium-voltage service connection?
At EB Corp we design, permit with the utility, and install medium-voltage service connections for industrial companies in Ecuador, in full compliance with current NEC standards. Feasibility study and no-obligation quote.