A steel mill cannot afford to wait. Every hour of downtime at a steel plant means tons of production that don’t reach the market, strained contracts, and broken supply chains.
When Optimus Steel LC—a steel mill located in Texas, United States—needed a distribution transformer custom-designed for its industrial loads, delivery time and technical precision were non-negotiable.
Tesla Transformadores manufactured the equipment, met the specifications to the letter, and shipped it to the North American market. That is the case.
The challenge: a Custom-Built Transformer for a demanding environment
Steel mills impose operating conditions that put any transformer to the test. Electric arc furnaces, frequency converters, and large-scale rectifiers: all are nonlinear loads that generate harmonics and degrade the power quality in the system.
The transformer required by Optimus Steel had to operate in that environment without degrading. The project parameters made this clear:
Rated power: 2.950 kVA
Primary voltage: 13.800 V — delta (D) connection
Secondary voltage: 800 V — star (yn) connection
Vector group: Dyn5
K-factor: K-20 — capacity to withstand severe harmonic currents
This was not a standard off-the-shelf transformer. It was equipment designed from the ground up to withstand the electrical conditions of the steel industry.
The Engineering Behind the Equipment
Grain-Oriented Silicon Steel Core
The transformer core was manufactured using grain-oriented silicon steel laminations, a material chosen for its high magnetic permeability and low hysteresis losses. In practical terms: less energy dissipated as heat, higher transfer efficiency, and a lower sustained operating temperature.
High-purity electrolytic copper windings
The windings were constructed from high-purity electrolytic copper. The material’s conductivity, combined with the precision of the winding process, ensures consistent electrical performance throughout the equipment’s entire service life.
Thermal design for K-20 factor
Nonlinear loads generate harmonic currents that heat the windings disproportionately compared to equivalent linear loads. The transformer design incorporates thermal sizing specifically for a K-factor of 20, ensuring control of temperature rise in both the oil and the winding hot spot, even under severe load conditions.
Electrostatic Shielding
The equipment incorporates electrostatic shielding between the primary and secondary windings. This feature reduces capacitive coupling between the two sides of the transformer, minimizing the transfer of high-frequency disturbances and transients to the plant’s internal power distribution network.
In a steel mill, where loads generate constant electrical noise, this shielding acts as a protective layer that preserves power quality in the process’s sensitive circuits.
Safety and Continuous Monitoring: Accessories That Can’t Be Improvised
A transformer in industrial operation without the proper instruments is a safety hazard. The equipment delivered to Optimus Steel was equipped with a set of accessories that ensure continuous monitoring and a safe response to any abnormal conditions:
• Coolant level indicator — visual monitoring of the oil at all times.
• Coolant thermometer with dry contacts — temperature alarm and trip.
• Buchholz relay with dry contacts — early detection of internal faults (gas and oil flow).
• Overpressure valve with dry contact — mechanical protection against abnormal pressures.
• Removable radiators with butterfly valves — design that facilitates maintenance without the need to drain the transformer.
Each accessory features dry contacts: a design choice that simplifies integration with plant monitoring and control systems.
From Funza to Texas: Colombian Manufacturing in the North American Market
This project is concrete proof that the Colombian manufacturing industry can compete, succeed, and deliver in one of the world’s most demanding markets.
The transformer was manufactured at the Tesla Transformadores plant in Funza, Cundinamarca—a 10.000 m² facility with an electrical testing field, a validation laboratory, and production lines equipped with industrial automation technology—and shipped to Texas under export terms agreed upon with the customer.
The delivery to Optimus Steel is not just a success story. It is part of Tesla Transformadores’ expansion strategy in the North American market, a market where demand for power transformers continues to grow and where quick response times and technical customization set the company apart.
Project specifications
| Customer | Optimus Steel LC |
| Industry | Steel industry |
| Project location | Texas, United States |
| Equipment type | Three-phase oil-immersed distribution transformer |
| Rated power | 2.950 kVA |
| Primary voltage | 13.800 V — delta connection (D) |
| Secondary voltage | 800 V — star connection (yn) |
| Vector group | Dyn5 |
| Winding conductors | High-purity electrolytic copper |
| Core | Grain-oriented silicon steel |
| K-Factor | K-20 (non-linear loads) |
| Shielding | Electrostatic shielding between windings |
| Protective accessories | Buchholz relay, pressure relief valve, thermometer (with dry contacts) |
| Manufacturing Standards | IEC / IEEE / NTC / RETIE 2024 |
| Quality certification | ISO 9001:2015 — Icontec |
| Manufacturing Plant | Funza, Cundinamarca, Colombia |
Does your next project have similar requirements?
Tesla Transformadores designs and manufactures custom distribution and power transformers tailored to demanding industrial processes, with competitive lead times and technical support from Funza to any location in Latin America and North America.
Talk to our team:
✉ export@tesla.com.co
📞 +57 318 282 6314
🌐 www.tesla.com.co
Note: Tesla Transformadores S.A.S. is a Colombian manufacturer of electrical infrastructure and has no affiliation with Tesla Inc. (electric vehicles).
