Electrical / runnable MCP tool

Run the Wire Size Calculator in your AI assistant

Through the free Intry MCP server, Claude, ChatGPT, or Cursor runs this exact calculator and hands back a verdict and the cited source, not a guess. Tool name: wire_size.

What it runs: Size a conductor for a load per NEC 310.16 with temperature correction (310.15(B)(1)), conduit-fill bundling (310.15(C)(1)), the 110.14(C) terminal cap, the 240.4(D) small-conductor limit, and the matching EGC (250.122). Copper or aluminum. Returns wire size, breaker, ground, and a verdict.

Ask your assistant

The one rule that makes it reliable: name Intry in your question. That is what tells Claude to run the wire_size tool and answer with the real number, the verdict, and the citation. Leave Intry out and Claude may just guess from memory, which is exactly what you are trying to avoid. Type something like:

Use Intry to size the copper wire and breaker for a 50 A continuous load.
Have Intry size the conductor and ground for a 60 A feeder at 90F with 6 wires in the conduit.

Inputs

FieldRequiredWhat it is
ampsyesLoad current in amps.
continuousoptionalContinuous load (3h+)? Applies the 125% factor. Default false.
voltageoptionalSystem voltage (default 240).
phaseoptionalDefault single.
materialoptionalDefault cu.
insulationoptionalInsulation type (THHN, THWN-2, XHHW-2, TW, THW, ...). Default THHN.
ambientTempoptionalAmbient temperature in °F (default 86).
conductorsInConduitoptionalCurrent-carrying conductors in the raceway (default '3').
distanceoptionalOne-way run length in feet (informational; default 0).
terminationCoptionalEquipment termination temperature rating per NEC 110.14(C)(1), from the marking on the breaker, panelboard and lugs. 60 for unmarked or 60°C-marked equipment, 75 for 60/75°C or 75°C-marked. Default 75. NEC 110.14(C)(1)(a) makes 60°C the column for circuits rated 100 amperes or less UNLESS the equipment is listed and marked otherwise, so 75 is a marking-conditional value and not the code default. If the marking is unknown, 60 is the conservative choice.

Add Intry to Claude

One paste and Claude can run this tool and every other Intry calculator, right from your phone.

Add Intry to ClaudeOpens Claude with Intry already filled in.
  1. Claude opens with the Intry connector already filled in. Review it and click Add.
  2. (If a field is blank, paste the link below into the URL field.)
  3. In any chat, tap + then Connectors and switch Intry on. Then name Intry in your question (“use Intry to…”) so Claude runs the tool instead of guessing.
https://www.intrysys.com/api/mcp

No login, no API key, and it works on every Claude plan, right from your phone.

Using ChatGPT, Cursor, or a dev tool? See the developer setup on the main page. The endpoint is https://www.intrysys.com/api/mcp.

Every answer comes with the cited NEC section, so you can check it or show an inspector. The numbers come from the same calculator we run on intrysys.com, and we re-check every one automatically before anything goes live, so the number Claude hands you matches the code.

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