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 current, distance, voltage and an allowed drop. Returns the smallest conductor that satisfies every constraint at once, not just the one you happened to think of.输入电流、距离、电压和允许压降，返回同时满足全部约束的最小线径，而不只是你想到的那一个。
Small-wire protection limits小导线保护上限
NEC 240.4(D) is built in. Ampacity tables alone would tell you 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.内置 NEC 240.4(D)。只看载流量表会告诉你 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 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，并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。
Ampacity tables载流量表
Copper and aluminium across the 60 °C, 75 °C and 90 °C temperature ratings, stored in the app.铜与铝在 60 °C / 75 °C / 90 °C 三种温度等级下的数据，全部内置。
Battery banks, fuses, inverters电池组、保险丝与逆变器
Series and parallel configurations, runtime estimates from depth of discharge and inverter efficiency, and protective device selection.串并联配置、按放电深度与逆变效率估算续航，以及保护装置选型。
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. Data corrections take priority over feature work. 问题、缺陷反馈和数据更正请发到 support@ai123.xyz。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。