{"openapi":"3.1.0","info":{"title":"Voltage Drop API","version":"1.0.0","description":"Cable voltage-drop and conductor-sizing maths as an API, computed locally and deterministically. The drop endpoint computes the voltage lost along a cable run from the current, the one-way run length, the conductor cross-section and the material: the conductor resistance R = ρ·L/A, the voltage drop Vd = k·I·R (k = 2 for single-phase, √3 for three-phase), the drop as a percentage of the supply and the voltage left at the load. The sizing endpoint works backwards: from an allowable percentage drop it returns the minimum conductor cross-section needed, A ≥ k·I·ρ·L/Vd_allow, rounds up to the next standard cable size (1.5, 2.5, 4, 6, 10, 16, 25 … mm²) and reports the actual drop at that size. The power endpoint computes the power dissipated as heat in the cable, P = N·I²·R (N = 2 or 3 current-carrying conductors), and the cable efficiency given a load power. Copper (ρ = 0.0172) and aluminium (ρ = 0.0282 Ω·mm²/m) are supported. Everything is computed locally and deterministically, so it is instant and private. Ideal for electrical-installation and panel-design tools, cable selection to wiring-regulation limits, solar, EV-charger and sub-main sizing, and electrical-engineering education. Pure local computation — no key, no third-party service, instant. Live, nothing stored. 3 endpoints. This is cable voltage drop and sizing; for Ohm's law, reactance and resonance use an Ohm's-law API and for transformer ratios use a transformer API.","contact":{"name":"PremiumApi","url":"https://www.oanor.com/by/premiumapi"}},"servers":[{"url":"https://api.oanor.com/voltagedrop-api","description":"oanor gateway"}],"tags":[{"name":"Voltage Drop"},{"name":"Meta"}],"components":{"securitySchemes":{"oanorKey":{"type":"apiKey","in":"header","name":"x-oanor-key","description":"Get your key at https://www.oanor.com/developer/keys"}}},"security":[{"oanorKey":[]}],"paths":{"/v1/drop":{"get":{"operationId":"get_v1_drop","tags":["Voltage Drop"],"summary":"Voltage drop over a run","description":"","parameters":[{"name":"current","in":"query","required":true,"description":"Load current I (A)","schema":{"type":"string"},"example":"20"},{"name":"length","in":"query","required":true,"description":"One-way run length L (m)","schema":{"type":"string"},"example":"30"},{"name":"area","in":"query","required":true,"description":"Conductor cross-section A (mm²)","schema":{"type":"string"},"example":"4"},{"name":"material","in":"query","required":false,"description":"copper | aluminium (default copper)","schema":{"type":"string"},"example":"copper"},{"name":"phases","in":"query","required":false,"description":"1 or 3 (default 1)","schema":{"type":"string"},"example":"1"},{"name":"voltage","in":"query","required":false,"description":"Supply voltage (V) for percentage","schema":{"type":"string"},"example":"230"}],"security":[{"oanorKey":[]}],"responses":{"200":{"description":"OK","content":{"application/json":{"example":{"data":{"note":"Vd = k·I·(ρL/A), k = 2 single-phase, √3 three-phase. 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