Type-tested assemblies to IEC 61439-2, rated for continuous industrial duty. Custom-engineered to project SLD with full form separation and arc-flash containment.
Our MDB range is the trunk of a complete LV network — built around copper busbars, cast-resin insulators, and ACB main incomers with full interlocking for source changeover and genset backup.
IEC 61439-2 defines four levels of internal separation. Each form determines how busbars, functional units, and outgoing terminals are segregated — and governs safe operation under live conditions.
| Form | Busbar | Functional units | Terminals for external conductors | Typical use |
|---|---|---|---|---|
| Form 1 | No separation between any internal components | Simple distribution, low-duty | ||
| Form 2b | Separated from functional units | Unseparated from each other | Within the same compartment | Standard commercial buildings |
| Form 3b | Separated from functional units | Separated from each other | In same compartment as functional unit | Industrial with maintenance needs |
| Form 4a | Separated | Separated | Same compartment as associated functional unit | Most industrial installations |
| Form 4b | Separated | Separated | Fully separated own compartment | Critical power · hospitals · data centers |
2mm zinc-coated structural members, 1.5mm body panels, bolted assembly for transport in sections up to 4 meters.
99.9% pure electrolytic copper busbars, tin-plated at contact surfaces, supported on cast-resin insulators rated 12kV.
Air circuit breakers (ACB) and moulded case (MCCB) from tier-1 European brands, with your choice of manufacturer.
Schneider PM5560 or equivalent, RS485 Modbus output, class 0.5S accuracy for revenue-grade monitoring.
Pressure relief flaps, ventilated roof, interlocked doors with trapped-key systems for safe isolation procedures.
All maintainable components accessible from the front. Back-to-wall installation possible, saving 30% floor space.