A/B Feed Load Balance Planner
Calculate normal A/B feed split and automatically check N-1 capacity after either feed fails.
Parameters
Results
Assumptions
- Dual-power-supply equipment shares the design load equally across both feeds. After one feed fails, the remaining feed must carry the entire design load.
Important notes
- Review the actual dual-feed topology, breakers, shared upstream paths and N-1 design. Each entered feed capacity is the usable capacity of one feed; equal normal loading alone does not establish N-1 resilience.
Calculation method
Design total load (kW) = device count × power per device (W) / 1000 × (1 + reserve % / 100). Each feed carries half the load normally; the surviving feed carries all of it after one feed fails. N-1 margin = capacity of one feed − design total load.
Worked example
Planning example: 20 devices at 500 W each, 20% reserve and 8 kW per feed. Design load is 12 kW and each feed carries 6 kW normally, so normal capacity passes. After a feed fails, the survivor must carry 12 kW; its margin is −4 kW and N-1 fails.
Scope and limitations
Balanced normal loading is not a failover test. Check device power-supply behavior, breakers and shared upstream failure points. Enter usable capacity per feed. This example is not an on-site load test.