During maintenance activities on our assets, a significant operational risk was identified related to the incorrect sequence of removal of temporary grounding clamps during the re-energization process. Specifically, the lack of a dedicated locking system for the “T”-type screw of temporary grounding clamps contributes to the possibility of inadvertent or unauthorized removal of these devices, increasing the risk of workplace accidents. 

Currently, there are no specific locking solutions on the market for the "T" type bolt on these clamps. Therefore, AXIA Energy is seeking to co-develop an innovative locking system that meets the operational and safety needs of its maintenance teams. 

1. Impacts of the Solution on Maintenance Activities: 

Develop a padlock-based locking system specifically for the “T”-type screw used in temporary grounding clamps applied in transmission lines, substations, and power plants, covering low, medium, and high voltage equipment. The system must: 

• Prevent accidental or unauthorized removal of the grounding clamp when the phase side is still connected. 

• Allow the removal of the ground clamp only after the safe removal of the corresponding phase clamp 

• Include alphanumeric coding (grounding card), considering the possibility of more than one grounding cable per phase, to facilitate identification and ensure the correct disconnection sequence—relying solely on three colors may cause confusion during disconnection. 

• For power plants and substations, the locking system must allow the use of the same temporary electrical ground for more than one work front. Therefore, the system must support multi-front locking for a single temporary grounding system (AET). 

     2. Technical Requirements: 

• Compatibility with the clamp models currently used by AXIA Energy in transmission lines, substations, and power plants. 

• Mechanical resistance, including resistance to weather and adverse conditions. 

• Easy installation and operation by field electricians, without requiring any additional tools (usability testing under end-user conditions: Transmission Line, Substation, and Power Plant electricians). 

• Use of non-conductive and resistant materials, such as high-strength nylon or polymers, ensuring mechanical and electrical safety up to at least 17 kV. 

     3. Recommended Tests and Trials: 

To ensure the effectiveness and safety of the developed locking system, the following tests are suggested: 

• Mechanical Strength Test 

Objective: Ensure that the locking system withstands the mechanical forces applied during installation and removal operations. 

Procedure: Apply mechanical forces simulating usage conditions to verify tensile, compression, and impact resistance. 

Reference Standard: Standards that define mechanical requirements for tools used in live-line maintenance. 

• Compatibility Test with Existing Clamps 

Objective: To verify the compatibility of the locking system with the temporary grounding clamp models currently used by AXIA Energy. 

Procedure: Install the locking system on various clamp models and assess fixation, conductivity, stability, and ease of operation. 

• Grounding Card Fixation Test 

Objective: Evaluate the effectiveness of grounding card attachment to the locking device. 

Procedure: Check the adhesion of grounding cards to the locking device. 

• Durability Test 

Objective: Assess the resistance of the locking system to adverse environmental conditions, such as temperature variation, humidity, UV radiation, and vibration. 

Procedure: Expose the locking system to temperature cycles, humidity, and UV radiation to check for changes in mechanical and visual properties. 

• Operational Safety Test 

Objective: Ensure that the locking system effectively prevents unauthorized or accidental removal of the grounding clamp. 

Procedure: Simulate removal attempts with the locking system installed, evaluating resistance and effectiveness of the lock. 

• Usability Test 

Objective: Assess the ease of use, ergonomics, and safety of the padlock-based locking system for temporary grounding clamps under real working conditions of electricians in transmission lines, substations, and power plants. 

Procedure: Simulate the use of the solution in realistic scenarios, with electricians using appropriate PPE, performing tasks like installation and removal of the locking system. During testing, factors such as operation time, ease of handling with appropriate class insulating gloves should be observed. Feedback from participants will be essential to evaluate ergonomics, efficiency, and safety of the system, enabling adjustments to ensure it meets the needs of field professionals. 

Deadline:The proposal submission form will be available until24/07/2025.  

Questions: For any questions or additional information, please send an email with the subject line identifying the title of this challenge to innovationgrid@eletrobras.com