High-Voltage Cables

Think of a hyperscale data centre's power supply chain the way you would think of any last-mile delivery problem, a GSU transformer, covered elsewhere on this site, might step voltage up to whatever level the grid needs, but that power still has to travel, physically, through cable, from substation to switchgear to every individual rack, and none of those runs use ordinary household wire, each is a purpose-built, precisely insulated high-voltage cable sized for a specific current and voltage.

High-voltage cables carry power between substations, GSU transformers and switchgear, covered elsewhere on this site, and their sizing is governed by how much current they need to carry continuously without overheating and by the insulation, typically cross-linked polyethylene, needed to contain the voltage safely, which is why a data centre's cable specification is a genuine engineering exercise rather than a simple bulk-purchase line item.

India's cable manufacturers have been explicit about how large this opportunity has become, KEI Industries' chairman has estimated cables account for roughly 3-5% of a data centre's total capital expenditure, translating into an incremental opportunity of around ₹25,000 crore across India's current 8-10 GW data centre build-out, with the segment overall projected to grow from about $5.5 billion in 2025 to over $13 billion by 2034, and Polycab, KEI Industries and RR Kabel holding roughly 18%, 9% and 7% of the broader Indian wire and cable market respectively.

This is the reason cable manufacturers now discuss "data centre order book" as a distinct, disclosed growth line in investor communications, a category that barely existed as a separate line a few years ago, sitting alongside their traditional construction, infrastructure and renewable-energy cable business.