Innovative Cost-Effective Automatic Circuit Brakers to Modernize LV Switchboards in Argentina

Challenge

The Current Situation and the Challenge

Enel is seeking solutions for the refurbishment of existing Low-Voltage (LV) switchboards in Argentina. 

The current LV switchboards that are installed in various substations are equipped with traditional fuse-based protection systems. While fuses provide basic protection, they lack the flexibility, safety features, and operational efficiency of modern circuit breakers. 

Fuses, by design, are single-use protective elements: they blow when there is an electrical fault and require manual replacement. This leads to longer downtimes, increased field interventions, and greater exposure to risks for maintenance personnel. Furthermore, fuse-based panels are often incompatible with modern monitoring and automation solutions, limiting the potential for smart grid integration. 

The goal of this initiative is to modernize and refurbish the switchboards by replacing the fuses with automatic circuit breakers, thereby aligning with Enel Grids' standards for safety, reliability, and maintainability. The upgrade will enable: 

• Remote monitoring and control, using breakers with communication capabilities; 
• Long-term cost savings by reducing maintenance interventions and downtime. 

The Solution's Required Features and Characteristics 

We are looking for innovative solutions and approaches for modernizing our Low-Voltage switchboards by replacing fuse-based protection with modern circuit breakers, while maintaining or enhancing existing functionality and ensuring compliance with electrical safety and performance standards. 

The core challenge is to develop or identify retrofit methods, components, or modular systems that can:

• Adapt to existing substations layouts, preferably without requiring full panel replacement. The replacement of the entire switchboard can be accepted as sub-optimal solution.
• Replace fused feeders with breaker-based feeders, supporting both manual and automatic operation (optimal solution without changing the switchboard).
• Improve protection coordination, enabling faster and more selective fault response.
• Enhance safety by reducing the risk of arc flash and electrical accidents during operation or maintenance.
• Enable future smart capabilities, such as remote monitoring, diagnostics, and control.

Innovative Features 

• Mechanical Compatibility: The proposed retrofit solution must fit within the dimensional and structural constraints of the existing panels or provide a modular redesign compatible with standard substations layout.
• Electrical Performance: Circuit breakers must support equivalent or improved electrical ratings compared to the existing fuse links, ensuring reliable protection under all operating conditions.
• Safety Standards: Compliance with IEC 61439 or equivalent international standards is mandatory. The equipment should have an appropriate Internal Arc Classification (IAC) to guarantee safety against internal arc faults, protecting personnel and infrastructure. Minimum safety features:

1. Disconnection with visible contact position, in alternative could be evaluated a certification of the kinematic chain test
2. System for the short-circuit and earthing of the LV lines
3. System for the locking of the circuit breaker in open position

• Maintenance Efficiency: Proposed solutions should minimize the need for manual interventions, particularly during fault conditions, by utilizing reliable and resettable circuit breakers that allow quick restoration of service without replacement components.
• Ease of Implementation: Solutions must be deployable efficiently—either directly on-site or through a controlled workshop refurbishment process—minimizing downtime and operational disruption.

Must Have Features

All variants must comply with IEC 61439 and support the following technical specifications:

• Rated Voltage: 400/230 V (nominal)
• Switchboard rated current: 1.600 A
• Feeder rated current: ≥ 420 A with thermal protection settable at 420 x 1,05 A
• Rated Frequency: 50/60 Hz
• Short-Circuit Withstand Current: ≥ 36 kA for 1 second (lower ratings could be considered, but would not cover all the needs)
• Internal Arc Classification (IAC): according to IEC 61641
• Automatic Circuit Breakers: Circuit breakers must provide precise, reliable protection against overloads, short circuits, and earth faults. They should be easy to operate and reset, reducing downtime significantly compared to fuse replacements. Single-pole circuit breakers are the preferred solution, three-pole circuit breaker can be considered as sub-optimal solution.
• Remote operation and monitoring: The ability to remotely operate and monitor the state of the circuit breakers is a preferred characteristic.
• Reclosing capability: The circuit breakers shall be capable of reclosing within 3 minutes followed by a reset of the protection. The reclosing could be:

1. self-operated, with an internal settable timer, with different setting and enabling /disabling functions for overcurrent or short-circuit trips (i.e. it shall be possible, for example, to set the reclosing function for overcurrent disabling it for short-circuit)
2. operated by the local RTU, that will manage the reclosing logic
3. remote operated

• Dimensions

Please find the dimension in the ANNEX here.

In case of solution that only replace fuses with circuit breakers, the solution shall be compatible with standard LV switchboards according to MAT-PMCA-PDD-21-0191-ESP technical specifications (ANNEX)

In case of replacement of the whole LV switchboard, it shall be compatible with existent switchboards (ANNEX) and substation layout, that could be:

1. standard substations at ground level
2. standard underground substations

Nice To Have

• IoT Sensors and Digital Supervision: Integration of IoT-enabled sensors for real-time measurement of current, voltage, temperature, and other operational parameters to perform data analytics through embedded electronics and IT components
• Advanced Communication Interfaces: Support for wireless or wired communication interfaces enabling seamless integration into utility communication networks.
• Predictive Maintenance and Fault Analytics: Capabilities to perform condition monitoring, fault prediction, and remote troubleshooting, reducing downtime and optimizing asset management

Must Have Deliverables:

The proposal must include a description and supporting documents that clearly demonstrate compliance with the relevant mandatory requirements.

In general:

• The proposal must be cost-effective and scalable with respect to the substitution of the entire switchboard.
• Each part of the proposal must include a technical description and all supporting evidence (e.g. drawings, datasheets, certifications, test reports) as required.

Proposals must be submitted in a single stage in Spanish (In case of English a Spanish translation is required to be attached) to the openinnovability.com platform and include a document containing the following sections:

1. Technical Solution Overview:

• Clear and concise description of the proposed system.
• Innovative features proposed compared to current solutions.
• Compatibility to be compared to Enel adopted solutions.

2. Innovative Design Overview:

• Clear description on how the solution allows and enhances mechanical compatibility, electrical performance, maintenance efficiency and safety.

3. Production & Supply Chain, required content & evidence:

• Technical support must be available in Argentina. Having a headquarters in Argentina would be considered an advantage.
• Description of the manufacturer’s quality system
• Overview of the production process, highlighting In-line verification and routine testing procedures
• Evidence of: industrial scalability, availability of redundant production facilities, and flexible logistics capabilities

4. Installation: description of the method

5. Compliance with must have:

• All the requisites in the MUST HAVE section has to be respected and evidence provided.

6. Execution time

• Project phases, timeline and deliverables: e.g., concept validation, prototype, testing, certification, prototype production.

7. Cost Analysis and Development Budget. Required content & evidence:

• Detailed unit cost and estimation of Total Cost of Ownership (TCO): service life, and maintenance and potential replacement costs
• Comparison with traditional LV switchgear solutions

Supplier Profile

Local presence in Argentina: To ensure responsiveness and support throughout the project lifecycle, suppliers should have a local presence and a Spanish-speaking team.

Production & Supply Chain: The manufacturer must operate under highly reliable production processes, incorporating in-line verification and rigorous routine testing. A high degree of automation and digital process control is required to guarantee product consistency and quality.

High-Volume Industrial Production: Suppliers must demonstrate the capacity for high-volume manufacturing with flexible logistics and supply chain management. The presence of multiple or backup manufacturing sites is highly desirable to ensure continuity of supply.

Internal Laboratory Facilities: Facilities must be equipped with state-of-the-art inspection and testing equipment