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PV DC Cable Capacity and Voltage-Drop Check

Check a PV DC cable against an entered current factor, derated capacity and two-conductor voltage-drop limit.

Inputs

Project inputs and assumptions

Range: 0.01–100,000 A

Enter the operating or maximum-power current basis from the module, string or combiner data.

Range: 0.01–10

Enter the project PV design-current factor; confirm the current CEC/AS/NZS basis rather than assuming this value is universal.

Range: 0.01–100,000 A

Enter the verified cable ampacity before the combined correction factor for the actual PV cable and installation method.

Range: 0.01–2

Enter the verified combined temperature, grouping and installation correction; do not double-apply factors already included in ampacity.

Range: 1–100,000 V

Enter the operating DC voltage for the percentage calculation.

Range: 0–100,000 m

Enter one-way route length.

Range: 0–100,000 Ω/km

Enter the conductor resistance at the selected temperature basis.

Range: 0.01–100 %

Enter the voltage-drop limit selected for the PV design basis; no universal percentage is assumed.

Range: 1–3

Use 2 for a positive and negative conductor path unless the selected DC model uses a different path representation.

Result

Adjusted DC cable capacity (A)
20.00
DC capacity margin (A)
-2.50
PV design current (A)
22.50
DC voltage-drop margin (%)
1.76
Estimated DC voltage drop (%)
0.24
Estimated DC voltage drop (V)
1.45
Result
The adjusted PV cable capacity is below the entered design current. Review the cable, correction factor and PV design-current basis.

Formula

Calculation logic

Formula definitions and substituted values.

Before relying on the result

  • Check PV string or combiner cable capacity
  • Screen DC voltage drop on a long PV route
  • Use module/inverter data, current CEC and AS/NZS 5033 requirements, temperature, grouping, isolator and protection data for final PV design.

Related calculators

Use module/inverter data, current CEC and AS/NZS 5033 requirements, temperature, grouping, isolator and protection data for final PV design.