Use a high-voltage warning sign compliant with ISO 7010, clearly indicating electrical hazard for all three levels of the distribution box.

Recommended Sign Features

• Symbol and Text: The sign should feature the internationally recognized high-voltage hazard symbol (ISO 7010 W012) with bold text such as “Danger: Distribution Board” or “High Voltage” to alert personnel to the risk of electric shock or fire .
• Color and Contrast: Use a yellow background with black text and symbol for maximum visibility, consistent with ISO 7010 standards .
• Material: Durable materials like rigid PVC or self-adhesive vinyl are recommended for indoor or outdoor use, ensuring longevity and resistance to wear .
• Size: Choose a size appropriate for visibility at the point of hazard:
  • A5 (148 × 210 mm) for compact panels
  • A4 (210 × 297 mm) for standard distribution room doors
  • A3 (297 × 420 mm) for high-traffic or high-visibility areas .

Placement Guidelines

• Location: Place the sign directly on the distribution box door or panel, ensuring it is unobstructed and visible from all access points .
• Height and Orientation: Position at eye level where possible, and ensure the sign is oriented so it can be read easily by anyone approaching the box.
• Multiple Levels: For a three-level distribution box, consider placing a warning sign on each level or at the main access point to ensure all potential hazards are clearly marked .

Compliance and Safety Considerations

• Regulatory Compliance: Using ISO 7010-compliant signage ensures adherence to international safety standards and local electrical safety regulations .
• Panel Clearance: Maintain at least 3 feet of clearance in front of the distribution box for safe access, as required by electrical codes .
• Maintenance and Visibility: Regularly inspect signs for damage, fading, or obstruction to maintain effectiveness in preventing unauthorized access and accidents . By following these guidelines, a three-level distribution box can be clearly marked to reduce the risk of electrical hazards, ensure compliance, and protect personnel.