Classification of Secondary Distribution Boxes on Construction Sites

Secondary distribution boxes are intermediate power panels on construction sites that safely route electricity from primary distribution points to specific zones, equipment, or buildings.

Overview and Function

Secondary distribution boxes serve as intermediate panels between the primary distribution cabinet and end-use equipment or tertiary distribution points. They are designed to distribute power to specific zones, such as floors, buildings, or construction areas, ensuring safe and reliable electricity supply while incorporating protection mechanisms like residual current devices (RCDs) and circuit breakers. These boxes are typically rainproof and robust, suitable for outdoor construction environments, and often feature double doors, coated surfaces, and copper busbars for optimal conductivity and durability.

They are part of a three-tier protection system: primary (main supply), secondary (zone-level distribution), and tertiary (equipment-level distribution), ensuring safety and fault isolation.

Common Types and Features

Zone Distribution Boxes

Route power to specific construction zones or floors. Equipped with RCDs and circuit breakers for each circuit. Often modular for flexibility and rapid deployment.

Lighting and Equipment Distributors

Designed for temporary lighting, pumps, or cranes.

Include CE

E and earthed sockets with upstream safety devices. Can handle rated currents up to AC 32 A with RCD protection.

Modular Pre-

Wired Boxes

Feature pre-cut, pre-tested cables and plug-in connectors. Allow easy installation under raised floors or accessible ceilings in temporary site offices or facilities. Reduce installation time and improve cable management.

Safety and Standards

Secondary distribution boxes on construction sites are manufactured to comply with IEC 61439 and IEC 60364 standards. Key safety features include: Residual Current Devices (RCDs) to prevent electric shock. One machine, one circuit breaker, one RCD, one box, one lock principle to avoid overloading and ensure isolation.

Rainproof and durable enclosures for outdoor use. Unit testing before deployment to ensure operational reliability.

Practical Deployment

Connected downstream of primary distribution cabinets. Serve multiple tertiary distribution boxes or end-use equipment. Can be rapidly deployed using pre-stocked connection distributors for temporary construction needs.

Suitable for large-scale construction sites, including residential complexes, commercial buildings, and infrastructure projects. Secondary distribution boxes are essential for safe, flexible, and reliable power management on construction sites, bridging the gap between main supply points and end-use equipment while ensuring compliance with safety standards and operational efficiency.