Power Loss in Cables Calculator - I²R Loss and Electrical Energy Waste

P = I² * R * n

P = Power losses(W)

I = Current(A)

R = Resistance(Ω)

n = Factor depending on circuit type / number of conductors

n = 2 for d.c. or a.c. single phase

n = 3 for a.c. three phase (assumed balanced)

This tool calculates power losses (I²R losses) in cables due to conductor resistance during current flow, based on IEC and NEC standards. It supports DC, single-phase, two-phase, and three-phase systems, including parallel conductors and various insulation types.

Input Parameters

1.Current Type: Direct Current (DC), Single-phase AC, Two-phase, or Three-phase (3-wire/4-wire)

2.Voltage (V): Enter phase-to-neutral voltage for single-phase, or phase-to-phase for polyphase

3.Load Power (kW or VA): Rated power of the connected equipment

4.Power Factor (cos φ): Ratio of active to apparent power, between 0 and 1 (default: 0.8)

5.Wire Size (mm²): Cross-sectional area of the conductor

6.Conductor Material: Copper (Cu) or Aluminum (Al), affecting resistivity

7.Parallel Phase Conductors: Conductors with same size, length, and material can be used in parallel; total permissible current is sum of individual core ratings

8.Length (meters): One-way distance from supply to load

9.Operating Temperature (°C): Based on insulation type:

• IEC/CEI: 70°C (PVC), 90°C (XLPE/EPR), 105°C (Mineral Insulation)

• NEC: 60°C (TW, UF), 75°C (RHW, THHN, etc.), 90°C (TBS, XHHW, etc.)

Output Results

1.Conductor Resistance (Ω/km)

2.Total Circuit Resistance (Ω)

3.Power Loss (W or kW)

4.Energy Loss (kWh/year, optional)

5.Voltage Drop (% and V)

6.Temperature correction for resistance

7.Reference Standards: IEC 60364, NEC Article 310

Designed for electrical engineers and installers to evaluate circuit efficiency, energy consumption, and thermal performance.