Primary & Secondary Power Distribution for Data Centers
Southern Electrical Services designs and installs complete primary and secondary electrical distribution systems for data centers across Texas — from utility interconnection through final distribution panels serving every load in your facility.
What Are Primary & Secondary Power Systems in a Data Center?
Primary power refers to the medium-voltage electrical system — typically 12.47kV, 13.8kV, or 34.5kV — that delivers utility power into a data center campus. Secondary power is the low-voltage distribution system (typically 480V 3-phase) that feeds all downstream equipment: UPS systems, PDUs, cooling units, and lighting. Southern Electrical Services installs and commissions both systems as prime contractor on data center projects throughout Texas.
Primary Power Distribution Services
Utility Service Entrance & Interconnection
We manage the complete utility interconnection process — coordinating with CenterPoint Energy, Oncor, AEP Texas, and other Texas utilities for new service, service upgrades, and meter installations up to 138kV. We handle all utility application paperwork, inspection scheduling, and cutover coordination.
Medium-Voltage Switchgear Installation
Metal-clad and metal-enclosed switchgear installation from 5kV through 38kV. We install, test, and commission primary switchgear from all major manufacturers including Eaton, ABB, Schneider Electric, and GE. Includes protective relay programming, trip testing, and full commissioning documentation.
Transformers — Dry-Type and Liquid-Filled
Installation of pad-mount and unit substation transformers from 750kVA through 10MVA+. Data center deployments typically use 2.5MVA–5MVA unit subs at 13.8kV–480Y/277V. We perform oil sampling, turns ratio testing, and full acceptance testing prior to energization.
Primary Selective and Secondary Selective Switching
Design and installation of primary selective and secondary selective switching schemes that allow a facility to transfer between utility feeders without interruption. Critical for data centers requiring Tier III and Tier IV electrical architecture.
Bus Duct and Busway Systems
High-amperage bus duct installation from main transformer secondary through main switchboard — including plug-in busway for flexible power distribution across the data floor. We install systems rated from 1000A through 6000A.
Secondary Power Distribution Services
480V Main Switchboard Installation
Main distribution switchboards rated from 2000A through 6000A serving UPS systems, mechanical equipment, lighting, and all other secondary loads. We size and install switchboards per NEC and NFPA 70E requirements for the calculated fault current and load.
Modular Power Distribution Units (PDUs)
Data center PDU installation including static bypass, input/output breakers, and branch circuit monitoring. We install floor-standing PDUs and overhead mounted units from Eaton, Vertiv, APC, and Starline — sized from 30kVA through 225kVA.
Mechanical Equipment Power Feeds
Dedicated power feeds to all mechanical equipment — chillers, cooling towers, CRAC/CRAH units, pumps, and air handling equipment. All feeds include properly sized conductors, conduit, disconnects, and overcurrent protection per NEC Article 430.
Power System Studies & Load Analysis
Before finalizing any distribution design, we perform short circuit calculations, arc flash hazard analysis per NFPA 70E, and protective device coordination studies to ensure your system is safe, compliant, and optimized for your load profile.
Frequently Asked Questions
What voltage is used for primary power distribution in a data center?
Most data centers in Texas receive utility power at 12.47kV, 13.8kV, or 34.5kV depending on the utility and facility power requirements. Smaller facilities (under 5MW) may receive service at 12.47kV, while large hyperscale campuses often interconnect at 34.5kV or higher to reduce transformer losses and conduit fill. Southern Electrical Services coordinates directly with Texas utilities to determine the optimal service voltage for your project.
What is the difference between N+1 and 2N power redundancy?
N+1 redundancy means one backup system exists for every N operating systems — for example, two transformer-switchgear pairs serving a facility that only needs one to operate. 2N redundancy means a complete duplicate of every system — two fully independent power paths (A-side and B-side) from utility through UPS to every rack. Tier III data centers typically require N+1; Tier IV requires 2N or 2(N+1).
How long does it take to install primary electrical systems for a data center?
Primary electrical installation timelines depend heavily on utility lead times, which in Texas can range from 90 days to 18+ months for new high-voltage services. Once equipment is on-site, a typical 5–20MW primary and secondary electrical installation takes 3–6 months. Southern Electrical Services coordinates utility interconnection, equipment procurement, and construction to compress schedule wherever possible.
What permits are required for data center electrical work in Texas?
Data center electrical work in Texas requires permits from the local authority having jurisdiction (AHJ) — typically the city building department. Electrical work must be performed by a Texas-licensed electrical contractor (TDLR license). Utility interconnection requires coordination and approval from the serving utility. Southern Electrical Services manages all permitting and utility coordination as part of our prime contractor scope.
Can you work with all Texas utility providers?
Yes. Southern Electrical Services has coordinated new utility services and service upgrades with CenterPoint Energy, Oncor, AEP Texas, Texas-New Mexico Power (TNMP), and other Texas electric utilities. We manage the service application, engineering approval, inspection, and cutover process from start to finish.
Request a Consultation
Discuss your primary and secondary power requirements with our data center electrical team.
Get a QuoteCredentials
- Texas Licensed — TDLR #TECL18759
- 35+ years in Texas
- Industrial-grade safety programs
- NFPA 70E compliant
- Serving all of Texas
Primary & Secondary Power for Your Texas Data Center
Southern Electrical Services delivers complete primary and secondary power distribution systems — on schedule, to spec, and with full prime contractor accountability.