| Correction Factor | BS 7671/HD 60364-5-52 | ERA 69-30 |
| Ca Ground temperature (°C) | 20°C | 15°C |
| Cd Installation Depth (m) | 0.7m | 0.5m |
| Cs Soil thermal Resistivity (K.m/W) | 2.5 K.m/W | 1.2 K.m/W |
Ca - Ground temperature (°C) – The lower ground temperature will allow the current rating of the cable to be increased.
Cd - Installation Depth (m) – The shallower depth also improves the current rating.
Cs - Soil thermal Resistivity (K.m/W) – a value of 1.2 K.m/W is where the soil is considerably moister. This is considered a more typical value for many parts of the UK.
The difference in these three key values leads to a significant derating of the current rating of buried cables.
Modecsoft recommends, however, that in all designs, the individual circumstances of the installation are accounted for. Correction factors applied should reflect the location-specific ground temperature, the depth of buried systems, ensuring the backfill is suitably compacted, and, if soil conditions are unknown, undertake specific soil analysis for Soil Resistivity.

