# PowerEngineerLab

> PowerEngineerLab publishes inspectable electrical and energy calculators for learning, early comparison, and engineering discussion. Results are estimates. They are not design approval, code compliance, or a manufacturer recommendation.

PowerEngineerLab is the name of this website. This file does not state a registered company, license, certification, or author.

## Languages

- English: /
- 简体中文: /zh-CN/

## Eight categories

- Electrical fundamentals & conversions / 电学基础: Start with voltage, current, resistance, reactance, and time-domain behavior. Build intuition from first principles. These tools connect quantities, units, and simple circuit models while keeping assumptions visible. Pages: /categories/electrical-fundamentals/ and /zh-CN/categories/electrical-fundamentals/.
- Wiring, circuits & protection / 配线与保护: Explore circuit behavior, conductor resistance, and voltage-drop candidates. Estimate electrical behavior before a qualified design review. Standards-based ampacity tables, installation corrections, code compliance, and protection coordination remain outside the current models. The cable estimate is a simplified parameterized thermal model only. Pages: /categories/wiring-protection/ and /zh-CN/categories/wiring-protection/.
- AC & three-phase power / 交流电力: Make real, reactive, and apparent power easier to see and compare for balanced single-phase and three-phase systems. Work through balanced AC relationships, power factor, and ideal reactance. Harmonics and unbalanced systems require methods beyond this first release. Pages: /categories/ac-three-phase/ and /zh-CN/categories/ac-three-phase/.
- Motors, transformers & generators / 电机与变压器: Explore transformer ratio, voltage regulation, and related machine calculations with the assumptions stated on each tool. Start with ideal transformer ratio calculations. Each tool states its assumptions and engineering limits. Pages: /categories/motors-transformers-generators/ and /zh-CN/categories/motors-transformers-generators/.
- Batteries, UPS & EV / 电池与 UPS: Frame stored energy, charge time, load capacity, and runtime assumptions. Compare ideal energy budgets without presenting them as battery-manufacturer curves. Chemistry, temperature, aging, and control limits stay explicit. Pages: /categories/batteries-ups-ev/ and /zh-CN/categories/batteries-ups-ev/.
- Solar & energy storage / 光伏与储能: Connect solar generation, storage, tariffs, and a simple project payback estimate in one category. Turn a transparent generation profile into an energy and cash-flow estimate. Production forecasts and financial scenarios remain assumptions, not guarantees. Pages: /categories/solar-storage/ and /zh-CN/categories/solar-storage/.
- Home & commercial energy / 能源使用: Understand what uses energy, what it costs, and how alternatives compare. Build explainable energy budgets from device-level inputs. Tariffs are user supplied and no regional price, tax, or utility rule is inferred. Pages: /categories/home-commercial-energy/ and /zh-CN/categories/home-commercial-energy/.
- Industrial efficiency / 工业能效: Compare losses, correction, energy savings, and lifecycle cost scenarios. Use simplified models to make tradeoffs legible before detailed engineering. Site measurements, tariffs, duty profiles, and standards still govern real decisions. Pages: /categories/industrial-efficiency/ and /zh-CN/categories/industrial-efficiency/.

## Published calculators (52)

English:

- Ohm’s Law Calculator (TOOL-001): /calculators/ohms-law/
- Series and Parallel Resistance Calculator (TOOL-002): /calculators/series-parallel-resistance/
- Voltage Divider Calculator (TOOL-003): /calculators/voltage-divider/
- AC Power Calculator (TOOL-004): /calculators/ac-power/
- Power Triangle Calculator (TOOL-005): /calculators/power-triangle/
- Power Factor Correction Calculator (TOOL-006): /calculators/power-factor-correction/
- Conductor Resistance Calculator (TOOL-007): /calculators/conductor-resistance/
- Capacitive Reactance Calculator (TOOL-008): /calculators/capacitive-reactance/
- Inductive Reactance Calculator (TOOL-009): /calculators/inductive-reactance/
- RC Time Constant Calculator (TOOL-010): /calculators/rc-time-constant/
- Appliance Electricity Cost Calculator (TOOL-011): /calculators/appliance-electricity-cost/
- Home Energy Use Calculator (TOOL-012): /calculators/home-energy-use/
- Energy Cost Comparison Calculator (TOOL-013): /calculators/energy-cost-comparison/
- Lighting Energy Savings Calculator (TOOL-014): /calculators/lighting-energy-savings/
- Appliance Replacement Payback Calculator (TOOL-015): /calculators/appliance-replacement-payback/
- Battery Runtime Calculator (TOOL-016): /calculators/battery-runtime/
- Battery Charging Time Calculator (TOOL-017): /calculators/battery-charging-time/
- UPS Sizing and Runtime Calculator (TOOL-018): /calculators/ups-sizing-runtime/
- Voltage Drop and Cable Sizing Calculator (TOOL-019): /calculators/voltage-drop-cable-sizing/
- Solar Energy and Payback Calculator (TOOL-020): /calculators/solar-energy-payback/
- Transformer Ratio Calculator (TOOL-021): /calculators/transformer-ratio/
- Transformer Voltage Regulation Calculator (TOOL-022): /calculators/transformer-voltage-regulation/
- EV Charging Time, Cost and Range Calculator (BACKLOG-001): /calculators/ev-charging/
- Generator Capacity and Starting Load Calculator (BACKLOG-002): /calculators/generator-sizing/
- Transformer Capacity, Loading and Losses Calculator (BACKLOG-003): /calculators/transformer-losses/
- Three-Phase Motor Current and Starting Analysis (BACKLOG-004): /calculators/motor-current/
- HVAC Running Cost Comparison (BACKLOG-005): /calculators/hvac-cost/
- Data Center Energy and UPS Planning (BACKLOG-006): /calculators/data-center-energy/
- Pump Energy and Variable-Speed Retrofit Analysis (BACKLOG-007): /calculators/pump-energy/
- Fan System Energy Analysis (BACKLOG-008): /calculators/fan-energy/
- Compressed-Air Leak and Savings Analysis (BACKLOG-009): /calculators/compressor-leak/
- Household Electrical Load and Capacity Estimate (BACKLOG-010): /calculators/household-load/
- Cross-tool Energy Project Portfolio Report (BACKLOG-011): /calculators/energy-project-portfolio/
- Storage Capacity Planning Calculator (BACKLOG-012): /calculators/storage-capacity-planning/
- Cable Ampacity Estimate Calculator (BACKLOG-013): /calculators/cable-ampacity-estimate/
- Solar DC Current Estimate Calculator (BACKLOG-017): /calculators/solar-dc-current-estimate/
- kW to HP Converter (BACKLOG-025): /calculators/kw-to-hp/
- Electrical Efficiency Calculator (BACKLOG-026): /calculators/electrical-efficiency/
- Load Factor Calculator (BACKLOG-027): /calculators/load-factor/
- Demand Factor Calculator (BACKLOG-028): /calculators/demand-factor/
- Diversity Factor Calculator (BACKLOG-029): /calculators/diversity-factor/
- Maximum Demand Calculator (BACKLOG-031): /calculators/maximum-demand/
- Cable Short-Circuit Withstand Calculator (BACKLOG-047): /calculators/cable-short-circuit-withstand/
- Neutral Conductor Current Screen (BACKLOG-049): /calculators/neutral-conductor-current-screen/
- PV String Design Estimate Calculator (BACKLOG-015): /calculators/pv-string-design-estimate/
- Solar Inverter Capacity Estimate Calculator (BACKLOG-016): /calculators/solar-inverter-capacity-estimate/
- Three-Phase Fault Current Estimate Calculator (BACKLOG-014): /calculators/three-phase-fault-current-estimate/
- Synchronous Speed Calculator (BACKLOG-070): /calculators/synchronous-speed/
- Motor Slip Calculator (BACKLOG-071): /calculators/motor-slip/
- Motor Torque Calculator (BACKLOG-072): /calculators/motor-torque/
- Transformer Full-Load Current Calculator (BACKLOG-054): /calculators/transformer-full-load-current/
- Data Center PUE Calculator (BACKLOG-073): /calculators/data-center-pue/

简体中文:

- 欧姆定律计算器 (TOOL-001): /zh-CN/calculators/ohms-law/
- 串并联电阻计算器 (TOOL-002): /zh-CN/calculators/series-parallel-resistance/
- 分压器计算器 (TOOL-003): /zh-CN/calculators/voltage-divider/
- 交流功率计算器 (TOOL-004): /zh-CN/calculators/ac-power/
- 功率三角形计算器 (TOOL-005): /zh-CN/calculators/power-triangle/
- 功率因数补偿计算器 (TOOL-006): /zh-CN/calculators/power-factor-correction/
- 导体电阻计算器 (TOOL-007): /zh-CN/calculators/conductor-resistance/
- 容抗计算器 (TOOL-008): /zh-CN/calculators/capacitive-reactance/
- 感抗计算器 (TOOL-009): /zh-CN/calculators/inductive-reactance/
- RC 时间常数计算器 (TOOL-010): /zh-CN/calculators/rc-time-constant/
- 家电用电费用计算器 (TOOL-011): /zh-CN/calculators/appliance-electricity-cost/
- 家庭能耗计算器 (TOOL-012): /zh-CN/calculators/home-energy-use/
- 能源成本比较计算器 (TOOL-013): /zh-CN/calculators/energy-cost-comparison/
- 照明节能计算器 (TOOL-014): /zh-CN/calculators/lighting-energy-savings/
- 家电更换回本计算器 (TOOL-015): /zh-CN/calculators/appliance-replacement-payback/
- 电池续航计算器 (TOOL-016): /zh-CN/calculators/battery-runtime/
- 电池充电时间计算器 (TOOL-017): /zh-CN/calculators/battery-charging-time/
- UPS 容量与续航计算器 (TOOL-018): /zh-CN/calculators/ups-sizing-runtime/
- 电压降与电缆选型计算器 (TOOL-019): /zh-CN/calculators/voltage-drop-cable-sizing/
- 太阳能发电与回本计算器 (TOOL-020): /zh-CN/calculators/solar-energy-payback/
- 变压器变比计算器 (TOOL-021): /zh-CN/calculators/transformer-ratio/
- 变压器电压调整率计算器 (TOOL-022): /zh-CN/calculators/transformer-voltage-regulation/
- 电动车充电时间、费用与续航计算器 (BACKLOG-001): /zh-CN/calculators/ev-charging/
- 发电机容量与启动负载估算 (BACKLOG-002): /zh-CN/calculators/generator-sizing/
- 变压器容量、负载率与损耗计算器 (BACKLOG-003): /zh-CN/calculators/transformer-losses/
- 三相电机电流与启动估算 (BACKLOG-004): /zh-CN/calculators/motor-current/
- 空调与热泵运行成本比较 (BACKLOG-005): /zh-CN/calculators/hvac-cost/
- 数据中心与服务器能耗及 UPS 规划 (BACKLOG-006): /zh-CN/calculators/data-center-energy/
- 泵系统能耗与变频改造分析 (BACKLOG-007): /zh-CN/calculators/pump-energy/
- 风机系统能耗分析 (BACKLOG-008): /zh-CN/calculators/fan-energy/
- 空压机泄漏与节能收益 (BACKLOG-009): /zh-CN/calculators/compressor-leak/
- 家庭配电负载清单与容量估算 (BACKLOG-010): /zh-CN/calculators/household-load/
- 跨工具能源项目组合报告 (BACKLOG-011): /zh-CN/calculators/energy-project-portfolio/
- 储能容量规划计算器 (BACKLOG-012): /zh-CN/calculators/storage-capacity-planning/
- 电缆稳态载流量估算器 (BACKLOG-013): /zh-CN/calculators/cable-ampacity-estimate/
- 光伏直流电流估算器 (BACKLOG-017): /zh-CN/calculators/solar-dc-current-estimate/
- kW 转马力换算器 (BACKLOG-025): /zh-CN/calculators/kw-to-hp/
- 电气效率计算器 (BACKLOG-026): /zh-CN/calculators/electrical-efficiency/
- 负载率计算器 (BACKLOG-027): /zh-CN/calculators/load-factor/
- 需用系数计算器 (BACKLOG-028): /zh-CN/calculators/demand-factor/
- 多样系数计算器 (BACKLOG-029): /zh-CN/calculators/diversity-factor/
- 最大需量计算器 (BACKLOG-031): /zh-CN/calculators/maximum-demand/
- 电缆短路热稳定计算器 (BACKLOG-047): /zh-CN/calculators/cable-short-circuit-withstand/
- 中性导体电流筛查 (BACKLOG-049): /zh-CN/calculators/neutral-conductor-current-screen/
- 光伏组串设计估算器 (BACKLOG-015): /zh-CN/calculators/pv-string-design-estimate/
- 光伏逆变器容量估算器 (BACKLOG-016): /zh-CN/calculators/solar-inverter-capacity-estimate/
- 三相故障电流估算器 (BACKLOG-014): /zh-CN/calculators/three-phase-fault-current-estimate/
- 同步转速计算器 (BACKLOG-070): /zh-CN/calculators/synchronous-speed/
- 电机转差率计算器 (BACKLOG-071): /zh-CN/calculators/motor-slip/
- 电机转矩计算器 (BACKLOG-072): /zh-CN/calculators/motor-torque/
- 变压器满载电流计算器 (BACKLOG-054): /zh-CN/calculators/transformer-full-load-current/
- 数据中心 PUE 计算器 (BACKLOG-073): /zh-CN/calculators/data-center-pue/

## Engineering guides

- Ideal Transformer Turns and Voltage Ratio: /guides/transformer-turns-and-voltage-ratio/ and /zh-CN/guides/transformer-turns-and-voltage-ratio/
- Transformer Voltage Regulation Percent: /guides/transformer-voltage-regulation-percent/ and /zh-CN/guides/transformer-voltage-regulation-percent/
- Balanced Three-Phase Power and Current: /guides/balanced-three-phase-power/ and /zh-CN/guides/balanced-three-phase-power/
- Lagging Load Power Factor Correction: /guides/lagging-load-power-factor-correction/ and /zh-CN/guides/lagging-load-power-factor-correction/
- DC Voltage Drop on a Two-Wire Cable: /guides/dc-voltage-drop-for-a-cable-run/ and /zh-CN/guides/dc-voltage-drop-for-a-cable-run/
- Steady-State Cable Thermal Current Estimate: /guides/steady-state-cable-thermal-current-estimate/ and /zh-CN/guides/steady-state-cable-thermal-current-estimate/
- UPS Sizing Versus Battery Runtime: /guides/ups-sizing-versus-battery-runtime/ and /zh-CN/guides/ups-sizing-versus-battery-runtime/
- Battery Runtime from Watt-Hours: /guides/battery-runtime-from-watt-hours/ and /zh-CN/guides/battery-runtime-from-watt-hours/
- Simple Solar Payback from Monthly Generation: /guides/simple-solar-payback-from-monthly-generation/ and /zh-CN/guides/simple-solar-payback-from-monthly-generation/
- PV String Voltage at Entered Temperatures: /guides/pv-string-voltage-at-entered-temperatures/ and /zh-CN/guides/pv-string-voltage-at-entered-temperatures/

## Teaching cases

- Voltage Drop for a Long Cable Run: /cases/voltage-drop-long-cable-run/ and /zh-CN/cases/voltage-drop-long-cable-run/
- Cable Cost and Loss Comparison: /cases/cable-cost-loss-comparison/ and /zh-CN/cases/cable-cost-loss-comparison/
- Residential Solar Energy and Payback: /cases/residential-solar-energy-payback/ and /zh-CN/cases/residential-solar-energy-payback/
- UPS Sizing for Essential Loads: /cases/ups-sizing-essential-loads/ and /zh-CN/cases/ups-sizing-essential-loads/
- Home Energy Use Breakdown: /cases/home-energy-use-breakdown/ and /zh-CN/cases/home-energy-use-breakdown/
- Transformer Turns Ratio: /cases/transformer-turns-ratio/ and /zh-CN/cases/transformer-turns-ratio/
- Three-Phase Power and Power Factor: /cases/three-phase-power-and-power-factor/ and /zh-CN/cases/three-phase-power-and-power-factor/
- UPS Battery Runtime: /cases/ups-battery-runtime/ and /zh-CN/cases/ups-battery-runtime/

## Entry points

- Home: / and /zh-CN/
- Calculator directory: /calculators/ and /zh-CN/calculators/
- Categories: /categories/ and /zh-CN/categories/
- Engineering guides: /guides/ and /zh-CN/guides/
- Teaching cases: /cases/ and /zh-CN/cases/
- Roadmap: /roadmap/ and /zh-CN/roadmap/
- About: /about/ and /zh-CN/about/
- Engineering methodology: /methodology/ and /zh-CN/methodology/
- Privacy: /privacy/ and /zh-CN/privacy/
- Contact: /contact/ and /zh-CN/contact/

## Calculation boundaries

- Each calculator states its formula, inputs, assumptions, and what it does not evaluate.
- Empty, non-numeric, out-of-domain, and non-finite inputs are rejected instead of returning a number.
- A clause or table number that was not opened against the cited document stays labeled UNVERIFIED and is not used as a limit.
- Source lines on a calculator show the title, institution, URL, section, verification date, and status only when that data is already stored. A missing URL stays missing or is labeled as a source-register URL.
- Teaching cases are worked examples, not customer projects or site surveys.
- Local projects stay in the browser. Share state that exists is placed in the URL hash. The local project screen is not part of this public index.

## Contact

Public email: Contact@PowerEngineerLab.com

Index generated from the published calculator registry. It is not a separate catalog.