Tools

Calculators that show their work

Each one follows the published code tables, cites the table it read, and refuses to answer when the arrangement falls outside what the code actually covers. No interpolation, no invented values.

  • CEC · NEC · LV & MV

    AC Conductor Sizing

    Sizes a conductor end to end: design current, base ampacity table, termination-temperature cap, ambient and grouping deratings, underground engineered tables, parallel sets, voltage drop, overcurrent protection, bonding, and raceway fill.

    Covers CEC Tables 1–4 and Appendix D (Diagrams D8–D11), NEC Table 310.16/310.17 and Informative Annex B, and the full NEC Table 315.60(C) medium-voltage set for single, triplexed, and three-conductor cable.

    Live Open tool
  • Overcurrent protection

    OCPD Sizing

    Selects a fuse or breaker against the conductor it protects: continuous-load factors, the next-standard-size-up allowance, standard device ratings, and the checks that stop you protecting a conductor with a device it cannot survive.

    Working to CEC Rule 14-104 with Table 13, and NEC 240.4 with 240.6(A).

    In development
  • Selectivity

    Coordination Study

    Plots time–current curves for series devices and finds where selectivity breaks: the fault current at which an upstream device beats the downstream one to the trip, and the margin you have left.

    Damage curves, inrush points, and arcing-current checks alongside the device curves.

    In development
A word on how to use these. They are engineering aids. Every result has to be verified against the code edition your Authority Having Jurisdiction has adopted, and signed off by a licensed engineer before it goes into a design. Where an arrangement falls outside a table's stated basis, the right answer is a Neher-McGrath or IEEE 835 study — not a tool.