01 — System Size
Panels, strings and BOS — sized from your plant capacity.
From kW to array count, min/max panels per string, inverter rating, DC cable, AC cable, earthing, and MCCB — all in one pass.
The Calculators
Switch between tools with a click, or use the ← → arrow keys.
System Inputs
01 / SizingHow to use: Enter plant capacity and panel/inverter specs. We'll size the array, strings, DC/AC cable, earthing and MCCB — all in one go.
Results — Sized
01 / Output
–
Panels
–
Inverter (kW)
–
Strings
| Min. Panels per String | – |
| Max. Panels per String | – |
| String Configuration | – |
| DC Wire | – |
| Phase / Cable Type | – |
| AC Wire (Aluminium) | – |
| Earthing Wire | – |
| MCCB | – |
Show formula details
DC wire is fixed at 4 sqmm/6 sqmm per string. For High Altitude & High Temperatue Region use 6 sqmm DC wire. AC wire — full-load current from inverter kW, +20% safety margin, PF 0.8, checked against catalogue ampacity and a 3% voltage-drop limit. Phase auto-selects from capacity (≤ 7 kW → single-phase, > 7 kW → three-phase). Voltage drop is computed at design current (post-derating). For full control, use the AC Wire Sizing tab.
String Sizing
02 / ConfigHow to use: Got a fixed panel count already? We'll split it into strings that fit under the inverter's cold-day Voc ceiling.
Results — Configured
02 / Output
–
Max / String
–
Total Strings
–
Max Voc, Cold (V)
| String Configuration | – |
Show formula details
Max panels per string = ⌊ Inverter Max DC / cold-day Voc ⌋. Cold-day Voc = Voc × (1 + tempco × (Tmin − 25)). Any remainder is spread as evenly as possible across strings — e.g. 2×11 + 1×10.
AC Wire Sizing
03 / CableHow to use: Enter your inverter kW, phase, cable length and voltage-drop limit. We pick the smallest standard aluminium cable that clears both current and Vd.
Results — Selected
03 / Output
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Recommended Cable
–
Required (A)
–
Actual Vd
| System Voltage | – |
| Full Load Current | – |
| Design Current (after derating) | – |
| Required Current (with safety margin) | – |
| Cable Type / Installation | – |
| Recommended Cable Size | – |
| Actual Ampacity | – |
| Actual Voltage Drop | – |
| Actual Voltage Drop (Volts) | – |
Show formula details
Required current = design current × (1 + safety margin). We scan standard Aluminium sizes and pick the first where ampacity ≥ required current and Vd ≤ your allowed limit. Voltage drop is computed at the design current (post-derating) using AC resistance at 70 °C conductor temperature. Single-phase uses Vd = 2·I·L·R/(1000·V); three-phase uses Vd = √3·I·L·R/(1000·V).