DC voltage drop
DC voltage drop: use dc current, one-way cable length, conductor cross-sectional area. Review the formula, worked example and calculation steps.
Inputs
Use the units shown—
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Formula & explanation
Drop V = current × resistivity × (2×one-way length)/area
Variables & units
- DC current
- A · minimum 0, maximum 1000000000000
- One-way cable length
- m · minimum 0, maximum 1000000000000
- Conductor cross-sectional area
- mm² · minimum 0.000001, maximum 1000000000000
- Conductor resistivity at operating temperature
- Ω·mm²/m · minimum 0.000001, maximum 1000000000000
- Supply voltage
- V · minimum 0.000001, maximum 1000000000000
Worked example
10 A, 20 m one-way, 2.5 mm² and 0.0175 Ω·mm²/m gives 2.8 V drop.
Assumptions
Two-conductor DC circuit at constant current; supply voltage is used only for the percentage. Not AC impedance, three-phase design or cable ampacity.
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