Preview — in active development. The ampacity calculator runs in production today as part of the underground agent’s tool catalog, but it isn’t exposed as a standalone HTTP service yet. We’re extracting it as ampacity-api in an upcoming release. Want early access? Email hello@epcstudio.io.

The ampacity service computes underground cable ampacity using the Neher-McGrath method, with corrections for soil thermal resistivity, burial depth, conductor grouping, and circuit loading. Same engine that drives the underground agent’s compute_ampacity tool today.

What it will do

  • Steady-state ampacity — return current-carrying capacity at code-defined operating points
  • Emergency overload ratings — short-duration overload current with thermal limits
  • Voltage drop — per-feeder drop given length, current, and conductor properties
  • Derating factors — soil resistivity, depth, grouping, ambient temperature

Planned shape

# preview — actual endpoint shape may shift before launch
curl https://$VERTICAL_AI_BASE_URL/compute \
  -H "Authorization: Bearer $VERTICAL_AI_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "conductor": { "size": "500_kcmil", "material": "copper" },
    "depth_ft": 4,
    "soil_resistivity": 90,
    "ambient_c": 20,
    "grouping": { "circuits": 2, "spacing_in": 7.5 }
  }'

Until it ships

You can call the same calculation today through the Underground gateway → by asking the agent for an ampacity check, or via the MCP server directly if you’re an early integration partner.

See also