MSB switchboard design — main switchboard schematics — Brisbane data centre.

Project overview

ASTCAD produced the complete electrical documentation for 2 × 2500 A main switchboards installed in a new Brisbane Tier III data centre. Documentation covered single-line diagrams, schematics, panel-builder shop drawings, cable schedules and as-built drawings.

The challenge

The data centre required A/B redundant feeds with automatic transfer switching and full SCADA integration. The owner had strict labelling and segregation standards beyond AS 61439, and the switchboards had to undergo type-test verification before site delivery.

Our approach

• Single-line diagrams for A and B feed architecture
• Detailed schematics for ATS, sub-circuits and SCADA tie-points
• Panel-builder shop drawings with internal layouts and busbar runs
• Cable schedules and termination diagrams
• Type-test compliance verification package

Deliverables

• 182 electrical drawings (SLDs, schematics, shop)
• Cable schedule (2,140 cables)
• Type-test compliance package
• Commissioning test sheets
• As-built documentation set

Outcome

The switchboards were built and commissioned within the data centre’s tight programme. SCADA integration testing passed first time. The owner has commissioned a further 6 MSB packages of similar specification under the same documentation standard.

How we approach MSB switchboard design

Main switchboard design for critical facilities starts with fault level, form of segregation and redundancy philosophy. For this class of project we confirm the prospective fault current at the MSB, select a Form 3b or Form 4 construction to suit maintenance access requirements, and document busbar sizing, bracing and temperature-rise compliance to AS/NZS 61439. Schematics cover every functional unit — incomers, bus couplers, feeders, metering and controls — with consistent device designations so the switchboard builder, electrician and facility engineer are reading the same language. Generator changeover and UPS-fed boards get interlocking logic documented explicitly, never left to interpretation.

What an MSB schematic package includes

Expect general arrangement and shipping-split drawings, single line diagrams, control schematics for changeover and monitoring circuits, equipment and cable schedules, label schedules, and type-test compliance references. We coordinate the drawing set with the manufacturer’s shop drawings and review their submissions against our design intent before fabrication, closing the loop that most projects leave open. As-built updates after factory acceptance testing are part of the service.

Switchboard coordination with the wider installation

A main switchboard never exists alone. Our MSB switchboard design documentation coordinates the board with generator control systems, UPS distribution, sub-board cascading and the metering scheme, so protection discrimination works across the whole installation rather than stopping at the MSB terminals. We run discrimination studies against the actual protective devices scheduled, publish the settings, and flag any unavoidable compromise explicitly for the client’s engineer to accept. Physical coordination matters equally: shipping splits are designed around the actual access route to the switchroom, and cable entry zones match the cable tray design so the installing electrician is not improvising with a hole saw on a type-tested assembly.

For data centres, hospitals and industrial plants where the main switchboard is genuinely critical, we offer design review of existing MSB documentation as well as new design. If your as-built drawings have drifted from the installed board — the usual situation after fifteen years of modifications — we can re-document the installation to current standards and give your maintenance team a drawing set that matches reality.