Formula: Single-phase: ΔV = 2 × ρ × L × I / A. Three-phase: ΔV = √3 × ρ × L × I / A
NEC/IEC limit: ≤3% for branch circuits (5% cumulative including feeder)
Rule of thumb: Increase cable 1 step for every 30% extra cable length beyond limit
About This Calculator
What this tool does: Evaluates AC-side voltage drop from inverter to loads to protect equipment performance and compliance.
Core idea: Voltage drop grows with current and line impedance; long feeders magnify the effect.
Mini Example
If feeder impedance causes 4% drop at full load, sensitive equipment may underperform or trip.
Quick Literacy Notes
- Excess drop can trigger nuisance trips in sensitive electronics and motors.
- Conductor upsizing often improves both efficiency and thermal margin.
- Validate drop at continuous and surge operating points.
Common Mistakes
- Checking drop only at nominal load, not surge conditions.
- Ignoring voltage quality at far-end loads.
Key Takeaways
- Voltage drop grows with current and line impedance; long feeders magnify the effect.
- Excess drop can trigger nuisance trips in sensitive electronics and motors.
- Avoid this mistake: Checking drop only at nominal load, not surge conditions.
Practical Checklist
- Calculate line drop at continuous load and worst expected surge events.
- Check far-end voltage against tolerance of sensitive equipment.
- Consider conductor upsizing when drop and thermal margin are both tight.
FAQ
Q1: Which feeder condition should be tested first for AC drop risk?
Quick Answer: Validate this first: Excess drop can trigger nuisance trips in sensitive electronics and motors.
Engineer Note: If this assumption drifts from real conditions, downstream outputs can remain numerically neat but operationally wrong. Confirm with measured or site-specific inputs before locking decisions.
Q2: What oversight most often causes undervoltage at remote loads?
Quick Answer: Avoid this first: Checking drop only at nominal load, not surge conditions.
Engineer Note: In practice, the next failure mode usually follows: Ignoring voltage quality at far-end loads. Address both together; correcting one while keeping the other often leaves the design bias unchanged.
Q3: When should I redesign conductor size instead of accepting drop?
Quick Answer: Use this calculator for fast screening and scenario comparison.
Engineer Note: For procurement, warranty, compliance, or commissioning decisions, move to detailed verification with datasheets, measured conditions, and project constraints. Core rule: Voltage drop grows with current and line impedance; long feeders magnify the effect.
English
العربية
日本語
한국어
Tiếng Việt
ไทย
Bahasa Melayu
فارسی
Bahasa Indonesia
ဗမာစာ
简体中文
香港中文
繁體中文
Русский
Deutsch
Nederlands
Italiano
Français
Español
Português
Afrikaans
Azərbaycan dili
Български
ਪੰਜਾਬੀ
हिन्दी
اردو
বাংলা
Հայերեն
Íslenska
Қазақ тілі
नेपाली
Српски језик
Kiswahili
తెలుగు
Basa Jawa
தமிழ்
मराठी
