Electrical / Electronics

Cable and feeder sizing designer

Manual verification of a selected cable and feeder: Ib, corrected Iz, protective device, voltage drop and explicit margins without normative tables.

Cable and feeder sizing designer

Manual verification of a user-selected cable and protective device without normative lookup tables or automatic sizing.

This tool performs a simplified check of data supplied by the user. It contains no normative tables and does not automatically select a cable or protective device. Iz, In, I2, correction factors and limits must come from an appropriate current source for the specific project.

Demonstration example — the values are not a design recommendation or a normative table.

Load

Enter the load data used to calculate design current Ib.

Active power P

Voltage U

Power factor cos φ

Cable and conditions

Enter the actual cable dimensions and values obtained from the appropriate source.

Cable length L

Conductor cross-section S

Resistivity ρ

Base continuous ampacity Iz

Enter Iz from an appropriate source for the actual cable and installation method.

Combined correction factor k

Enter the combined correction factor resulting from the adopted conditions.

Protective device

Enter data for the selected protective device.

Protective-device rated current In

In and I2 must come from the data for the selected protective device or another appropriate source.

Operating current I2

Criteria

Enter the voltage-drop limit adopted for this project.

Maximum permitted voltage drop

This is a user-selected project criterion, not a normative default.

No current result. Enter data or load a demonstration and select Calculate.

Formulas and calculation method

Ib = \frac{P}{(U \cdot \cos_{phi})}

{Iz}_{corrected} = Iz \cdot k

{Delta}_{U} = \frac{2 \cdot Ib \cdot ρ \cdot L}{S}

{Delta}_{U_percent} = \frac{{Delta}_{U}}{U} \cdot 100

Ib \leq In

In \leq {Iz}_{corrected}

I_{2} \leq 1.45 \cdot {Iz}_{corrected}

Project and results

Assumptions and model limitations

The simplified voltage-drop model uses the supplied resistivity and does not include full cable impedance unless the user supplies additional data.

The tool has no normative tables or automatic cable/protective-device selection. It uses a simplified resistive voltage-drop model without full R/X impedance. It does not check short-circuit thermal withstand, automatic disconnection, PE/N sizing, harmonics, selectivity or temperature effects beyond the user-entered correction factor. It does not verify the source of Iz, In, I2, k or limits.

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Cable and feeder sizing designer

Formulas and calculation method

Project and results

Assumptions and model limitations

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Formulas and calculation method

Project and results

Assumptions and model limitations