kVA Tools – IEC Cable Sizing Calculator

Size cables per IEC 60364-5-52, catering for grouping, soil, ambient temperature factors, harmonic neutral loading, voltage drop, and other variables. See Documentation.

Project Title

Input

Load & System	Design Method
	System Type
	System Voltage (V)
	Load (kW or kVA)
	Power Factor (cosφ for Ib)
	Design Load Current I_B (A)
Power Factor (for ΔV)
OCPD Rating I_n (A)
Cable & Installation	Conductor Material
	Insulation Type
	Installation Method
	Loaded Phase Conductors	IEC Annex E neutral loading rules will be applied when THDi > 15%.
Ambient & Soil	Ambient Air Temperature (°C)
	Ambient Ground Temperature (°C)	Used mainly for buried/ducted methods (D1/D2).
	Soil Thermal Resistivity (K·m/W)	Typical values: 1.0–2.5 K·m/W. IEC base is often 2.5.
	Number of Circuits Grouped	Grouping factor f_group is applied if > 1.
Harmonics & Voltage Drop	THDi (%)	If THDi > 15%, neutral is treated as loaded (Annex E).
	Circuit Length (m)
	Voltage Drop Limit (%)	Typical design limits: 3% for lighting, 5% overall.
Short Circuit	Fault Current at Cable (kA)
	Fault Duration (s)
	k-factor Override (optional)	If blank, a typical k value is used for the material/insulation.

Output – Results

Item	Value	Units
Selected Phase Conductor Size	—	mm²
Selected Neutral Size	—	mm²
Table Ampacity I_tab	—	A
Derated Ampacity I_Z	—	A
IZ / IB Margin	—	—
OCPD Coordination (I_B ≤ I_n ≤ I_Z)	—	—
Voltage Drop	—	V
Voltage Drop	—	%
Short-Circuit Required Size	—	mm²
Short-Circuit Check	—	—

Output – System Factors

Factor	Value	Comment
Temperature Factor f_temp	—	Ambient vs rated temp
Soil Factor f_soil	—	Soil resistivity vs reference
Grouping Factor f_group	—	Number of circuits grouped
Harmonic Factor f_harm	—	Neutral loading due to harmonics
Total Factor f_total	—	f_temp × f_soil × f_group × f_harm
Ampacity Check	—	I_Z vs I_B
Voltage Drop Check	—	ΔV vs design limit

IEC 60364 Note: —

Output – Parameter Status

Category	Status
Input Validation	—
Harmonics & Neutral Loading	—
Grouping Effects	—
Implementation Notes	Table-based ampacity model with representative IEC values. For critical applications, verify against manufacturer-specific cable data and applicable national standards.