DC Electrical Calc
Wire sizing, voltage drop and ampacity — offline, on site.线径选型、压降与载流量计算 —— 完全离线，现场可用。
Overview概述
A DC electrical calculator for 12 V, 24 V and 48 V systems. Enter the current, the one-way distance and the system voltage, and get the smallest conductor that satisfies voltage drop, ampacity and overcurrent protection at the same time — plus a plain statement of which of the three is actually limiting the result.面向 12 V / 24 V / 48 V 直流系统的电气计算器。输入电流、单向距离和系统电压，得到同时满足压降、载流量与过流保护三个约束的最小线径 —— 并明确告诉你这三个约束里到底是哪一个在限制结果。
What it does功能
Wire sizing线径选型
Enter the current, the one-way distance, the voltage and an allowed drop. Returns the smallest conductor that satisfies voltage drop, ampacity and the NEC 240.4(D) small-conductor limits at the same time — not just the one you happened to think of. Ampacity alone would say a 14 AWG copper conductor can carry 25 A; the protection rules do not allow it, and the app says so instead of quietly passing it.输入电流、单向距离、电压和允许压降，返回同时满足压降、载流量与 NEC 240.4(D) 小导线保护上限的最小线径 —— 而不只是你想到的那一个。只看载流量表会说 14 AWG 铜线能载 25 A，但保护规则不允许，App 会直接指出来，而不是悄悄放过。
Voltage drop压降计算
Forward calculation for a size you already have, with the formula and the substituted values shown, so the answer can be checked by hand or handed to an inspector.正向计算：给定已有线径算压降，展开显示公式与代入的数值，结果可以手算复核，也可以拿给验收方看。
Fuse & breaker保险丝与断路器
Protective device rating for a conductor you already have, checked against what that conductor can actually carry.给定导线选保护装置，并校验它不超过该导线实际能承载的电流。
Ohm's law & power欧姆定律与功率
Fill in any two of volts, amps and ohms. The third value and the power are solved from them.伏特、安培、欧姆三者中任填两个，第三个值与功率随之求解。
Battery bank电池组配置
Series and parallel cells into one bank — voltage, capacity and watt-hours.把电芯串并联成一个电池组 —— 电压、容量与瓦时。
Inverter sizing逆变器选型
Continuous and surge watts, to compare against a nameplate.连续功率与启动浪涌瓦数，用来对照设备铭牌。
Runtime续航估算
How long the bank lasts at a given load, from depth of discharge and inverter efficiency.按放电深度与逆变器效率，估算电池组在给定负载下能撑多久。
Ampacity & conductor tables载流量与导线表
Ampacity to NEC 310.16 — copper and aluminium at 60 °C, 75 °C and 90 °C — plus conductor areas and circular mils. Every table states its source and edition inside the app.载流量取 NEC 310.16（铜与铝 × 60 / 75 / 90 °C），外加导体截面积与圆密尔。App 内每一张表都标明出处与版本。
What it does not do它不做什么
It does not size AC circuits, it does not do load calculations for a whole installation, and it is not a substitute for the code book. Where a table is missing from the underlying data source we treat the answer as not satisfied rather than guessing a value.它不做交流回路选型，不做整套装置的负载计算，也不能替代规范原文。数据源里缺失的表，我们按「不满足」处理，而不是猜一个数。
Getting help获取帮助
Questions, bug reports and data corrections go to support@ai123.xyz, or see the DC Electrical Calc support page. Data corrections take priority over feature work. 问题、缺陷反馈和数据更正请发到 support@ai123.xyz，也可见 DC Electrical Calc 技术支持页。数据更正的优先级高于新功能。
Privacy隐私
No accounts, no analytics, no advertising. Read the full privacy policy. 没有账号、没有统计、没有广告。完整说明见隐私政策。