Arc-proof device for secondary distribution box

Arc-resistant switchgear and arc flash mitigation devices protect personnel and equipment by detecting, containing, and redirecting arc energy in secondary distribution systems.

Key Solutions

1. ABB Arc Guard (TVOC-2) ABB's TVOC-2 is an optical arc flash mitigation device that detects the light from an arc flash and signals the breaker within 1 millisecond, achieving a total arc fault clearing time of 50 milliseconds when paired with Emax 2 circuit breakers. It can be enhanced with a current sensing unit (CSU-2) to prevent nuisance tripping in environments with strong ambient light, ensuring rapid and reliable protection for secondary distribution panels . 2. Eaton Arc-Resistant Switchgear (Magnum DS) Eaton's Magnum DS arc-resistant low-voltage switchgear is designed to contain and redirect arc energy safely away from operators. It is tested to ANSI/IEEE C37.20.7 standards and carries a Type 2B rating, providing protection even when secondary doors above breakers are open. The switchgear safely handles arcs in breaker, bus, or cable compartments without increasing the footprint, making it suitable for secondary distribution applications . 3. Siemens WL Arc-Resistant Low Voltage Switchgear Siemens WL switchgear is engineered to contain internal arcing faults within the enclosure. Arc chutes cool and extinguish the arc, while exhaust ducts vent byproducts outside the room. The system is tested to ANSI/IEEE C37.20.7 standards, ensuring personnel safety during routine operations such as breaker racking or instrument reading without opening covers . 4. Rittal Power Isolation Enclosures Rittal offers a solution that separates high and low voltage equipment within enclosures, minimizing personnel exposure to line-side power. Partition walls and segregated compartments allow maintenance and monitoring to be performed externally, reducing the need for PPE and enhancing safety in secondary distribution boxes .

Considerations for Implementation

• Standards Compliance: Ensure devices meet ANSI/IEEE C37.20.7 or NFPA 70E standards for arc-resistant switchgear.
• Reaction Time: Optical arc detection devices like ABB TVOC-2 provide millisecond-level response to minimize fault energy.
• Enclosure Design: Arc-resistant switchgear should contain and redirect arc energy, venting safely to prevent injury and equipment damage.
• Maintenance and Monitoring: Solutions like Rittal enclosures allow external access for programming and monitoring, reducing exposure to arc flash hazards.
• Customization: Many systems offer modular configurations to fit specific secondary distribution layouts and operational requirements.

Summary

For secondary distribution boxes, arc-proof solutions include optical arc flash detectors, arc-resistant low-voltage switchgear, and power isolation enclosures. These devices and systems are designed to protect personnel, minimize equipment damage, and maintain operational continuity by rapidly detecting, containing, or redirecting arc energy while complying with industry safety standards .