Industry — Data Centers
Power distribution built for concurrent maintainability and steady load growth
Data center electrical systems are judged on availability, maintainability and how well they absorb growth. Apex engineers low- and medium-voltage distribution for 2N and N+1 topologies, integrates main-tie-main and transfer logic, and adds monitoring that puts breaker, relay and meter data in one place for operations.
Operating realities
What makes data centers distribution its own discipline
Redundant topologies that must survive maintenance
2N and N+1 architectures only deliver their design availability if every element can be isolated without dropping load. That drives drawout breaker construction, tie breakers with proper interlocking, and maintenance bypass paths around UPS input and output. Concurrent maintainability has to be verified against the one-line diagram, not assumed from the topology name.
Coordinating MTM and ATS transfers with the UPS
Main-tie-main transfer at the medium-voltage or 480 V level must be sequenced with generator start, ATS operation and UPS battery ride-through. Transfer times, open- or closed-transition choices and lockout logic need to be settled early in design. A scheme that fights the UPS static bypass, or that leaves the tie closed with both mains, is a failure mode.
Selective coordination at high fault currents
Paralleled sources and 4,000 A class buses produce high available fault current at 480 V. Selective coordination between LVPCB trip units, feeder breakers and downstream PDU protection is a study exercise that includes zone-selective interlocking and arc-flash incident energy limits. Results should be revisited whenever load or source configuration changes.
Density growth and commissioning at scale
Rack densities keep rising, and the distribution system has to accept added load without restacking switchgear. Spare cells, bus ratings with margin and metering on every feeder make expansion an engineering task rather than an outage. Level 4 and Level 5 commissioning requires documented sequences, simulated failures and verified alarm points before the facility carries load.
How Apex fits
LV, MV, automation and monitoring for data centers
Low-voltage equipment
480 V switchgear and switchboards sized for build-out
Apex engineers UL 1558 low-voltage power switchgear with drawout LVPCBs where availability and maintainability justify it, and UL 891 switchboards where fixed-mount ICCBs fit the design. Bus ratings, tie positions and spare compartments are laid out against the planned build-out, not just day-one load.
Learn moreMedium-voltage equipment
Medium-voltage service and generator connection
Metal-clad switchgear at 15 kV or 27 kV class with vacuum circuit breakers handles utility service entrance, generator paralleling and unit substation feeds. Arc-resistant construction and remote racking are evaluated against the operating model and the electrical room layout.
Learn moreAutomation & controls
MTM transfer, ATS sequencing and interlocking
PLC- or relay-based main-tie-main logic, generator paralleling and ATS sequencing are engineered and documented against the facility's operating modes. Interlocks enforce that only two of three MTM breakers are closed unless paralleling is intended, and every automatic action remains subject to approved protection and control procedures.
Learn moreMonitoring & analytics
Breaker, relay and meter data in one view
Trip unit status, relay events, waveform captures and power-quality metering are brought into SCADA or the EPMS and the historian over Modbus TCP or IEC 61850 where applicable. Sequence-of-events records and health scoring support root-cause analysis and maintenance planning; recommendations stay with the operator.
Learn moreTypical equipment
What a data centers one-line usually contains
- 15 kV class metal-clad switchgear with 1,200 A or 2,000 A vacuum circuit breakers
- 480 V UL 1558 low-voltage power switchgear, drawout LVPCBs, 3,200 A to 5,000 A bus
- 480 V UL 891 service-entrance and house-power switchboards
- Main-tie-main automatic transfer controls with breaker interlocking
- Automatic transfer switches for mechanical and house loads
- Generator paralleling switchgear with sync-check and load-sharing controls
- Power-quality meters and waveform capture on mains and critical feeders
- SCADA and EPMS integration gateways (Modbus TCP, IEC 61850 where applicable)
Codes and standards that commonly apply
Specifications govern
- Low-voltage power switchgear is typically listed to UL 1558 and built to IEEE C37.20.1; switchboards are typically listed to UL 891. Which applies depends on the equipment type the project specifies.
- Metal-clad medium-voltage switchgear is generally built to IEEE C37.20.2, with arc-resistant designs tested per IEEE C37.20.7 when the specification calls for them; the project specification governs.
- NEC Article 645 and Article 708 requirements may apply depending on how the facility and its loads are classified; the authority having jurisdiction and project specifications govern.
- Applicable listings, standards and design requirements depend on equipment type, configuration, project specifications and jurisdiction.
Questions we hear
Frequently asked
+When does low-voltage power switchgear make more sense than a switchboard for a data center?
When the design requires drawout breakers, 100%-rated devices, a 30-cycle short-time withstand rating and compartmentalized construction so a breaker can be serviced without de-energizing the bus. Switchboards remain a sound choice for house power and less critical distribution where fixed-mount ICCBs and a smaller footprint fit the space and budget. The choice should follow the availability and maintenance model, not the label.
+Can Apex add MTM controls to existing switchgear from another manufacturer?
In many cases, yes. Apex has engineering and integration experience across ABB, Eaton and Schneider Electric power platforms, and transfer logic can often be implemented with new relays or a PLC while retaining the existing breakers. Feasibility depends on breaker auxiliary contacts, control power, available cell space and the condition of the existing equipment, so the work starts with a site survey and a review of the existing drawings.
+How is switchgear monitoring added without creating a path into the IT network?
Switchgear communications are engineered as an operational technology network, segmented from IT systems with gateways, firewalls and role-based access as defined in the facility's cybersecurity plan. IEC 62443 concepts guide the architecture where the owner requires them. Monitoring provides visibility and recommendations; switching remains under the operator and the approved control scheme.
Related engineering resources
Read next
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Main-Tie-Main Systems: Design and Automatic Transfer Logic
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Switchboard vs. Switchgear: What Actually Differs
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Apex Power Distribution · ApexPower.ai
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