Schneider Electric Main Distribution Board (MDB)

The Schneider Electric Main Distribution Board (MDB) entry describes an IEC 61439-compliant primary power distribution solution built around Schneider product families: the Prisma Set type-tested switchboard platform, Masterpact MTZ incoming ACBs, Compact NSX/Molded Case Circuit Breakers (MCCBs) for feeder protection, TeSys contactors for control loads, and Linergy busbar and connector systems. Prisma Set is a modular, type-tested assembly platform commonly applied for LV switchgear and distribution up to 4000 A in standard configurations; for higher primary ratings Masterpact MTZ ACBs provide compact, withdrawable or fixed incoming protection up to 6300 A. The Linergy busbar family delivers a type-verified busbar system with laboratory-proven temperature-rise characteristics and high short-time withstand for rated short-circuit currents in the 50–100 kA (1 s) range when configured and tested accordingly. Design and verification are executed to IEC 61439-1 and IEC 61439-2 (power switchboards and assemblies), with component compliance to IEC 60947 series (circuit-breakers, contactors, protection devices). Where distribution boards or split bus configurations are required, IEC 61439-3/6 evaluations and routine tests are applied as appropriate. Standard MDB parameters are: rated voltage up to 690 VAC, rated currents up to 6300 A, short-circuit ratings typically 50–100 kA (1 s) depending on configuration and coordination, and IP protection from IP31 to IP54 (Prisma Set assemblies can be detailed to IP55 in special builds). Internal segregation is implemented in Form 2b through Form 4b to achieve separation of busbar, functional units, and withdrawable compartments, enabling safer live-work procedures and selective maintenance. Protection strategy integrates incoming ACBs (Masterpact MTZ) with Micrologic protection units for instantaneous, short-time, long-time and ground-fault functions plus embedded metering. Outgoing feeders use Compact NSX or other MCCBs with adjustable trip curves for selective coordination. Residual current devices and earth-fault protection are provided per system needs; Schneider PowerLogic/ION/PM8000 metering and EcoStruxure Power monitoring can be used for energy, power quality and SCADA integration. For installations in potentially explosive atmospheres, IEC 60079 requirements must be addressed—use only certified Ex-rated switchgear/components or build segregation/enclosure strategies to meet zone requirements. Typical applications include building central plant distribution, data center main switchboards, industrial plant switchgear, utility substations and renewables infeed. Type testing per IEC 61439 (temperature-rise, dielectric properties, short-circuit withstand, IP/ingress and mechanical operation) is performed on representative Prisma Set configurations; routine and verification tests are carried out on each MDB prior to shipment. Patrion engineering provides customization, coordination studies, selectivity analysis, and factory acceptance testing to ensure Schneider Electric MDB assemblies meet site-specific electrical, mechanical and protection requirements.