From the grid to the load — how transformers, switchboards and cables work together, and why one partner for the whole chain de-risks your project.
Electricity flows from the grid to the load through four coordinated stages. Each must be rated to work with the next.
The “power chain” is the sequence of equipment that carries electricity from the utility connection — or on-site generation — all the way to the equipment that uses it. In a data center it ends at the server rack; in a mining hall, at the ASIC; in a factory, at the motor or process load. Every link must be sized and rated to work with the ones beside it.
Get the coordination right and the system is safe, efficient and reliable for decades; get it wrong and you face overheating, nuisance trips, or an under-rated board that cannot safely clear a fault. This guide walks the chain link by link, the way Evenson Power engineers and supplies it.
Power arrives from the utility at a voltage far too high to use directly, so the first link is a transformer that steps it down (or, in generation, steps it up for transmission). The transformer’s rating in kVA or MVA must cover the connected load with sensible headroom; its voltage class sets the insulation level; and its impedance (%Z) determines how much fault current it will deliver downstream.
These choices ripple through the entire chain, which is why the transformer is specified first. Evenson Power supplies units from 300 kVA to 240 MVA, certified to IEEE, IEC, CSA and DOE.
Once stepped down, power needs to be distributed and protected — the job of the low-voltage switchboard. A UL 891 switchboard takes the transformer’s output through a main device and divides it into protected feeder circuits via group-mounted breakers, all behind a dead-front for operator safety.
The critical coordination here is the interrupting rating: the board must safely interrupt the maximum fault current the transformer can deliver — a figure that comes directly from the transformer’s impedance. Evenson Power boards are rated 800–6,000 A, up to 100 kAIC.
Between every stage, and out to the loads, power travels through conductors. Cable and busbar must be sized for continuous current, for voltage drop over distance, and for the heat they generate in real installation conditions.
Under-sized conductors waste energy and overheat; correctly sized ones keep losses and temperatures in check across the long, high-ampacity runs typical of data centers and mining halls. Evenson Power supplies power, bare, aerial-bundled, control and building cable to IEC 60228 and local codes.
Each link constrains the next: transformer impedance sets the fault level; the fault level sets the switchboard interrupting rating; the switchboard and load set the conductor sizing; and protection must coordinate across all of them so a fault is cleared by the nearest device, not the main. When separate vendors specify each link, the gaps between them become the customer’s risk.
Sourcing the chain from one partner means the ratings are coordinated, the standards aligned, the documentation consistent, and one team accountable from quotation through commissioning — removing interface risk and compressing delivery. Backed by EP Group’s global sourcing and authorized brand partnerships.
Size the load and transformer with our free electrical calculators, read the transformer and UL 891 switchboard buyer’s guides to choose between options, and see the industry pages for how the chain is tuned to data centers, mining, utilities, renewables and industry.
Transformers to IEEE/ANSI C57 and IEC 60076; UL 891 switchboards to UL 891 and NEC; cables to IEC 60228 — genuine, documented, test-verified product an engineer or inspector can rely on.
Transformer, switchboard and cable — engineered together, certified and delivered as one coordinated package.
Request a Quote