Auto Sizing

Equipment sizing that keeps up with you

Cables, breakers, and transformers size themselves automatically per NEC as you build the model. Change a motor HP and watch every upstream device adjust.

What you get

Cable sizing per NEC

Ampacity, derating factors, and conductor selection — all automatic based on your circuit configuration.

Breaker & fuse sizing

Overcurrent protection device sizing per NEC 240, including standard trip sizes from NEC 240.6.

Live updates

Change any load and watch cable sizes, breaker ratings, and protection settings adjust automatically.

Scenario-based coincidence modeling

Model noncoincident behavior directly on loads and scenarios so sizing and load flow use the same operating assumptions.

NEC 2023 compliant

Sizing follows current National Electrical Code requirements including ampacity tables and derating.

Override capability

Engineering judgment wins. Override any auto-sized value when the situation calls for it.

Parallel conductors

Automatic parallel conductor sizing when a single conductor isn't sufficient.

How auto sizing saves hours

Manual equipment sizing means flipping through NEC tables for every circuit. ekx does it automatically for every device in your model, and keeps it updated as you make changes.

  • Cable sizes calculate the moment you connect a load
  • Breaker trip settings follow NEC requirements automatically
  • Change a motor HP and every upstream size adjusts
  • Model noncoincident behavior directly on loads and scenarios
  • Override any value when engineering judgment says otherwise

Start free. Upgrade when you need more.

Free tier includes 1 project with up to 2 buses. Paid plans start at $27/month for consultants and $149/month for unlimited access.

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Frequently asked questions

Which NEC edition does ekx follow?

NEC 2023. Sizing calculations reference current ampacity tables, derating factors, and overcurrent protection requirements.

Can I override auto-sized values?

Yes. Any auto-sized value can be overridden manually. The system will flag if your override doesn't meet NEC minimums.

Does it handle parallel conductors?

Yes. When a single conductor can't carry the required ampacity, ekx will automatically size parallel conductor sets.

How do multiple panels on one bus size upstream equipment?

Upstream equipment sizes from the same modeled load assumptions used in load flow. If downstream panels are noncoincident, represent that directly on the loads or in scenario overrides so the whole system stays on one basis.

What devices does it size?

Cables (conductors), overcurrent protection devices (breakers and fuses), and transformers. Sizes update live as you change the model.

Stop flipping through NEC tables.

Auto equipment sizing that updates as you design. Per NEC 2023.

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