R1 + R2 calculator
Calculate line and protective-conductor resistance from supplied resistance per kilometre.
Every result has a reason.
Enter your values and calculate to see the result, formula and working here.
R₁ + R₂ = r₁L₁ ÷ 1,000 + r₂L₂ ÷ 1,000Two uniform conductors in series at the conditions of the supplied Ω/km values. Enter each actual conductor length once. Excludes joints, parallel paths, reactance and temperature changes. No ring-circuit relationship, measured test prediction, Zs limit or compliance assessment is applied.
What the numbers mean.
Resistance per kilometre multiplied by length in kilometres gives the conductor resistance. Add the line and protective conductor resistances to obtain the series sum. Supplied resistance data must describe the actual conductor material, construction and temperature.
A worked example
20 m at 10 Ω/km gives R1 = 0.2 Ω. A separate 20 m at 20 Ω/km gives R2 = 0.4 Ω. Their sum is 0.6 Ω.
Validation, precision and limitations