Cable Routing and Trenching Calculator

Compare two trench layouts for one block of string cable: cable length, voltage drop and trench length.

Planning aid with invented defaults. The block, string current, voltage, conductor size and prices are placeholders, not a design or market data. The model counts string cable only: no combiners, DC feeders, AC cable, slope or obstacles. Trench width and depth are not modelled.
Preset:

Method: each string goes the shortest way to the nearest trench line (a stub across the rows), then along the trench to the spine, then along the spine to the centre of the block. Trench lines run across the block at every k rows from the centre line; the spine runs down the middle. Resistance per metre is R = ρ × L ÷ A, with ρ corrected for temperature as ρ20 × [1 + α × (T − 20)]. Copper ρ20 = 1.724e-8 ohm metre, α = 0.00393 per °C; aluminium 2.65e-8 and 0.0038 (Engineering ToolBox, at 20°C). Drop is current × resistance of the two conductors, as a share of string voltage. Quantity take-off adds the slack percentage to conductor length. The lower bounds use straight-line and right-angle distances from each string to the block centre.