PRELIMINARY ENGINEERING TOOL

Preliminary cable-size calculator

Evaluate custom cable data in ascending size order. Production automatic cable tables are intentionally not included.

Inputs

Design current

Target voltage drop

Ambient correction

Grouping correction

Other correction

Custom candidatesOne line per candidate: size mm², ampacity A, optional voltage drop %. Empty or malformed values are rejected; these are your own data, not a supplied standard table.

Size	Corrected Iz	Voltage drop	Status
2.5 mm²	17.28 A	4.2%	ampacity, voltage drop
4 mm²	23.04 A	2.7%	ampacity
6 mm²	29.52 A	1.8%	Pass
10 mm²	41.04 A	1.1%	Pass

Calculation steps

It = Ib / Ctotal = 25 / 0.720 = 34.72 A

Iz = Iz(table) × Ctotal. Formula ID: CABLE_SELECT_CUSTOM_V2

Assumptions and references

Preliminary calculation only. Verify inputs, manufacturer data, applicable standards, fault levels, and local requirements before construction or procurement.

UNDERSTAND THE TOOL

What this calculator does

Sort the cable candidates you supply and expose which preliminary checks each candidate passes or fails.

How to use it

Enter design current and target drop.
Supply traceable candidate and correction-factor data.
Review corrected ampacity and voltage-drop outcomes.
Independently verify the selected candidate before procurement.

Fields and meanings

Design current: Expected load current used for the comparison.
Base ampacity: A value from your own traceable dataset.
Correction factors: User-supplied multipliers for relevant conditions.
Cable data: Candidate size and any enabled voltage-drop or thermal information.

Review required. A passing custom-data result is not approval, certification or an installation instruction.

Read the full explanation →