Terms & Disclaimer

Not professional engineering advice

本工具结果仅供教育、设计规划与一般信息参考，不构成专业工程建议或持证安装建议。工程规范与电气法规因地区而异，实际安装必须由持证电工依据当地现行法规执行。误用计算结果可能导致电气火灾、设备损坏或违反法规。所有数值请自行核对现行 NEC 版本。

Code editions change

The National Electrical Code is revised on a three-year cycle and is adopted with local amendments. Always verify against the edition enforced in your jurisdiction.

Values still pending verification

Numeric tables used by these calculators are being checked against the code text and reviewed by a licensed electrician. Until that review is complete and credited on the Methodology page, results should be treated as unreviewed.