Offshore Wind Cable Thermal Headroom Calculator
Estimate the adjusted ampacity of export or array cables when site-specific soil conditions diverge from catalogue ratings, and quantify the resulting thermal headroom.
Feasibility-stage estimator. Validate with IEC 60287/IEC 60853 thermal models and site-specific seabed studies before construction decisions.
Examples
- Reference ampacity 1,100 A at 1.0 K·m/W, site resistivity 1.35 K·m/W, export current 920 A, burial factor 0.95 ⇒ Adjusted ampacity 899.39 A with -20.61 A headroom (overload risk).
- Reference ampacity 950 A at 1.0 K·m/W, site resistivity 0.85 K·m/W, export 720 A, optional factor blank ⇒ Adjusted ampacity 1,030.42 A with 310.42 A headroom (within limit).
FAQ
Where do the resistivity values come from?
Use thermal resistivity measurements from CPT or grab-sample campaigns, or calibrated seabed thermal models. Align measurement depth with final burial depth.
How should I treat thermal backfill systems?
Incorporate the effect as a burial adjustment factor. Values below 1.0 derate the cable, while engineered backfill with high conductivity can push the factor above 1.0.
Does the method account for dynamic loading?
The calculation reflects steady-state RMS current. Pair it with transient thermal analyses for short-term overcurrent events or emergency ratings.
Additional Information
- Result unit: amps and relative headroom percentage.
- Burial adjustment defaults to 1.0 so catalogue ampacity scales only with soil resistivity when no correction is provided.
- Square-root correction mirrors IEC 60287 approximations for homogeneous soils; apply detailed thermal models for layered seabeds.