Dual-Corded Power

Dual-corded power is a server power arrangement in which each device has two power supply units fed from two independent distribution paths. As a result, the loss of one path does not interrupt the load. The A-side and B-side cords connect to separate PDUs, usually backed by separate UPS systems and, in 2N designs, separate utility and generator chains. Most enterprise servers and network switches ship with two supplies and share the load roughly 50/50, each supply able to carry 100% alone. Single-corded gear is made resilient with a static transfer switch or an automatic transfer switch at rack level. Dual-corded feeds are the practical basis of 2N and concurrently maintainable designs, letting operators service one path while the other carries the load. A common failure is both supplies landing on the same path, which removes the redundancy.