High Voltage Connection Integrity
Calculation tool

Current-Carrying Capacity Calculator

Tube rail, solid rod, plate and flexible cable — heat-balance method per IEC TR 61597 (2021). Indicative, not a certification value.

Conductor type
Environmental conditions

Mind the contact material/joints: bare Al/Cu often 90°C, silver-plated 105°C, insulated cable per insulation class (PVC 70°C, XLPE 90°C).

0.3–0.6 m/s = common reference point for outdoor installations without specific wind data.

Bare/polished ≈0.2 · weathered ≈0.4–0.5 · matte/dark painted ≈0.85.

Current-carrying capacity (single conductor)
2,577 A
OD 80mm
R_AC (at T2)
24.02 µΩ/m
R_DC: 22.27 µΩ/m
P_rad
46.6 W/m
radiation
P_conv
112.9 W/m
Re: 2,586
Skin depth δ
14.3 mm
k_s: 1.078
Show calculation — formulas & intermediate values (IEC TR 61597)
Heat balance
I_max = √[ (P_rad + P_conv − P_sol) / R_AC ]
Resistance (AC, at T2)
R_DC = ρ₂₀·(1+α·(T2−20)) / A
δ = √( ρ(T2) / (π·f·µ₀) )  ·  k_s ≈ 1 + 0,25·(t/δ)²  ·  R_AC = R_DC·k_s
A=1,810mm² · ρ(T2)=4.030e-8Ω·m · R_DC=22.27µΩ/m · δ=14.3mm · t/δ=0.56 · k_s=1.078 → R_AC=24.02µΩ/m
Radiation loss P_rad
P_rad = σ·π·D·K_e·(T2⁴ − T1⁴)
D=80.0mm · Ke=0.50 · T1=308.1K · T2=353.1K → P_rad=46.6W/m
Convection loss P_conv (forced)
Re = 1,644×10⁹·v·D·[T1+0,5(T2−T1)]⁻¹'⁷⁸
Nu = 0,65·Re⁰'² + 0,23·Re⁰'⁶¹  ·  P_conv = π·λf·Nu·(T2−T1)
Re=2,586 · Nu=30.9 → P_conv=112.9W/m
Engineering estimate, not a standardised/certified value. Sensitive to Ke, v and the T2 assumption. For a rectangular/square plate an equivalent diameter (perimeter/π) is used for convection and an equivalent radius (√(area/π)) for the skin effect — lower accuracy than for the round variant; verify against manufacturer data or IEC 61439 / IEC 60890 for a final design. Short-circuit strength, mechanical deflection and connection points are not included here.