In this article, we present a case study on one of the most discreet yet essential components of a circuit breaker: the terminal. Despite its small size, this part plays a crucial role in circuit protection, enabling connection and disconnection of the current in the event of a fault.
Discover how ETMA develops and manufactures this component, from design and material selection to the rigorous production processes that ensure maximum quality and performance.
THE CHALLENGE
In the electrical sector, component safety and reliability are critical factors. In the case of circuit breakers, one of the key elements for power disconnection is the terminal, a small component responsible for connecting and disconnecting the electrical voltage source.
In this specific case study, a French multinational in the electrical sector challenged ETMA to develop a terminal capable of ensuring total safety and efficiency in the event of a short circuit while meeting the strict standards required by the industry.
The project involved not only manufacturing the component but also optimising the production process to meet the high market demand.
THE SOLUTION
The terminal developed by ETMA consists of four main elements:
- Clamp – a metal component that secures the electrical cable;
- Shaft – a metal part that forms the mechanical connection of the structure;
- Screw – an element that allows the terminal’s fixation and adjustment;
- Plastic part – an insulating component supplied by an external provider.
To transform these parts into a high-quality final product, ETMA utilised its unique system of 10 integrated production processes, including:
- Prototypes
- Tools and Equipments
- Stamping
- Cold Forging / Screws
- Wire Forming
- Heat Treatments
- Surface Treatments
- Assembly
- Inspection and Sorting
STEP-BY-STEP PRODUCTION PROCESSES
The execution of this project reflects the combined use of ETMA’s various production processes. The company provides all the necessary capabilities in-house to carry out this solution.
Development and Prototyping
The process begins in the prototyping department, where ETMA’s technical team fine-tunes the three-dimensional model of the component and its respective production tools. For each terminal model, a specific tool is developed, ensuring precision in large-scale production.
Production of Metal Parts
- Clamp Manufacturing – Steel sheets are fed into eccentric presses, where they go through a progressive tool that performs successive operations until the final shape is achieved.
- Shaft Production – A steel wire roll is shaped and cut into small cylindrical units. This highly efficient process has a production capacity of 2,200 pieces per hour.
- Screw Manufacturing – The screw is formed through a cold forming process in a multi-station machine, which transforms the steel wire into its final shape in five successive steps.
- Assembly and crimping of the sub-assembly – The clamp and shaft are joined in an automatic assembly and crimping process, eliminating the need for manual intervention. Production reaches 25 subassemblies per minute.
Treatments for Resistance and Durability
To ensure optimal mechanical properties, the metal components undergo specific treatments:
- Tempering and Annealing – Applied to the screw, this thermal process modifies the steel’s structure to increase its strength and durability. Tempering occurs at 870°C, followed by rapid cooling in oil.
- Electroplating – All metal elements receive a zinc coating via electrodeposition, increasing corrosion resistance and improving electrical conductivity.
Final Assembly and Quality Control
In the final phase, the various components are assembled in an almost fully automated process, ensuring precision and efficiency. The automatic inspection system verifies each unit, ensuring that only compliant parts are shipped to the customer.
ETMA manufactures 24,000 parts per day, exporting 5 million terminals per year to the most demanding markets.
THE RESULTS
The solution developed by ETMA Metal Parts exceeded the client’s expectations, delivering a product with high precision, reliability, and durability. The production capacity and process automation enabled efficient manufacturing while maintaining high-quality standards and ensuring competitiveness in the electrical sector.
This project not only reinforces ETMA’s position as a key supplier in the electrical industry but also demonstrates the impact of its technical and technological expertise in creating safe and efficient solutions.
ADVANTAGES OF CHOOSING ETMA AS A PARTNER
The terminal is already a historic product at ETMA and is a clear example of the benefits clients gain by working with a company that integrates multiple production processes in a single product. The 10 integrated production processes offer several advantages, such as:
- Greater control over processes and their interaction, resulting in increased flexibility;
- Shorter lead times, especially in multi-process production (for example, if heat and surface treatments had to be outsourced, lead time would increase exponentially);
- Cost optimisation in terms of logistics and quality.
The accumulated experience over the years in this and similar processes allows ETMA to understand interconnections and anticipate potential cascading effects among various processes, foreseeing problems and solutions. Moreover, this process interconnection can be studied and tested quickly, ensuring that processes self-adjust and that the manufactured product meets the customer’s exact needs.
CONCLUSION
The production of this terminal reflects ETMA’s commitment to innovation, quality, and excellence in manufacturing metal components. The combination of advanced technology, technical expertise, and automated processes ensures effective solutions for complex challenges in the electrical industry.
If your company is looking for a partner for the development and manufacture of high-precision metal parts, contact ETMA Metal Parts to discover how we can support your projects with innovative and efficient solutions.
