Electrical / runnable MCP tool

Run the Biggest EV Charger Calculator (NEC 220.87 + EVEMS) 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: max_ev_charger.

What it runs: Answer 'what is the BIGGEST EV charger I can install without a panel upgrade?' Inverts the NEC 220.87 existing-load method: from the service size and the measured 12-month peak demand it returns the largest standard EVSE output that fits (headroom / 1.25 / voltage, floored to a standard rating) plus the branch wire/breaker/ground. Optionally pass a load-management device TYPE (shed = DCC, throttle = Emporia/Wallbox Power Boost, circuit-share = Splitvolt) to get the device-enabled charger. FIRE LOCK: the branch is ALWAYS sized to 125% of the FULL EVSE hardware output, never the shed/throttle setpoint; the only legitimate branch reduction is the EVSE's own restricted-access adjustable rating (NEC 625.42(B)). An external EMS relaxes only the service/feeder calc (625.42(A)/220.70/750.30).

Ask your assistant

The one rule that makes it reliable: name Intry in your question. That is what tells Claude to run the max_ev_charger 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:

Ask Intry for the biggest EV charger a 100 A service with a 60 A measured peak can take.
Use Intry to check how big an EV charger a DCC load-management device lets me install on a 40 A breaker.

Inputs

FieldRequiredWhat it is
serviceAmpsoptionalService / main breaker rating, e.g. 100, 125, 150, 200.
voltageoptionalService/charger voltage (default 240; use 120 for Level 1).
demandSourceoptionalSource of the peak-demand figure (default utility).
demandValueoptionalExisting measured peak demand.
demandUnitoptionalUnit of demandValue (default a).
materialoptionalBranch conductor material (default cu).
distanceoptionalOne-way run length in feet (informational; default 0).
deviceoptionalLoad-management device TYPE. Omit for the plain 220.87 inverse solve.
deviceRatingAmpsoptionalshed: the EVSE pass-through breaker; circuit-share: the existing shared-branch breaker; throttle: the EVSE hardware output.
hardwareOutputAmpsoptionalThe full EVSE hardware output the branch is protected to. Defaults from device+deviceRatingAmps if omitted.
evseAdjustedRatingAmpsoptionalNEC 625.42(B): the EVSE's OWN restricted-access adjustable rating. The ONLY legitimate branch reduction; never an external device.

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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