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 screw used in 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 while the phase-side connection remains in place.
• Allow 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, facilitating identification and ensuring the correct disconnection sequence. Relying solely on three color codes may lead to confusion during disconnection.
• For power plants and substations, allow the use of the same temporary electrical grounding system for more than one work front. The solution must therefore support multiple lockout points for a single Temporary Electrical Grounding (TEG).

 

2. Technical Requirements

 

• Compatibility with the grounding clamp models currently used by AXIA Energy in transmission lines, substations, and power plants.
• Mechanical resistance, including resistance to weather exposure and adverse environmental conditions.
• Easy installation and operation by field electricians without requiring additional tools, validated through usability testing under real operating conditions for transmission line, substation, and power plant electricians.
• Use of non-conductive and durable materials, such as high-strength nylon or engineering polymers, ensuring mechanical and electrical safety for voltages of at least 17 kV.

 

3. Recommended Tests and Trials

 

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

 

3.1 Mechanical Strength Test

 

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

Procedure: Apply mechanical forces that simulate actual operating conditions to evaluate tensile, compressive, and impact resistance.

Reference Standard: Applicable standards defining mechanical requirements for tools used in live-line maintenance.

 

3.2 Compatibility Test with Existing Clamps

 

Objective: Verify compatibility between the locking system and the temporary grounding clamp models currently used by AXIA Energy.

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

 

3.3 Grounding Card Fixation Test

 

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

Procedure: Verify the adhesion and retention of grounding cards on the locking device under expected operating conditions.

 

3.4 Durability Test

 

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

Procedure: Expose the locking system to temperature cycling, humidity, and UV radiation to evaluate changes in mechanical and visual properties.

 

3.5 Operational Safety Test

 

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

Procedure: Simulate removal attempts while the locking system is installed, evaluating its resistance and lockout effectiveness.

 

3.6 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 experienced by electricians in transmission lines, substations, and power plants.

Procedure: Simulate the use of the solution under conditions that closely resemble actual field operations. Electricians should use the appropriate PPE while performing installation and removal tasks. Factors such as operation time, ease of handling while wearing the corresponding class of insulating gloves, and overall safety should be evaluated. Participant feedback will be essential to assess ergonomics, efficiency, and operational safety, enabling adjustments that ensure the solution meets the needs of field professionals.

 

Deadline

 

The proposal submission form will remain available until 24/07/2025.

 

Questions

 

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

 

 

Temporary Grounding Systems | Grounding Clamps | Lockout and Tagout (LOTO) | Electrical Safety | Occupational Safety | Transmission Line Maintenance | Substation Maintenance | Power Plant Maintenance | Asset Maintenance | Utility Operations | Field Workforce Safety | High Voltage Equipment | Safety Engineering | Industrial Safety | Mechanical Engineering | Advanced Polymer Materials | Electrical Protection Systems | Human Factors and Ergonomics