This myCableEngineering software FAQ answers common questions about using our software.
Earthing
Earth Return Paths
The earth return paths include all (armour, screen, etc.) but not any path through the earth or ground. This is extremely complicated to calculate, would require additional information and any resultant value would be significantly large compared to any other return path.
If you are noticing high values of R2 or Z2, please ensure that you have specified some form of metallic earth return path.
Cable Sizing
When should I use User Defined Rating (UDR)?
Use User Defined Rating when the sustained current capacity of the cable has been determined outside the standard sizing tables available in myCableEngineering. This may be appropriate where the rating comes from a manufacturer’s datasheet, a project-specific calculation, a specialist installation method or another recognised engineering assessment.
When using UDR, enter the current rating, the conductor operating temperature and the conditions that apply to that rating. The value is then used by the software for downstream checks such as voltage drop, impedance and fault-rating calculations.
For most cases, you will want to select a sizing standard from the dropdown box. This will allow you to size and determine the correct CSA for your cable.
Can I calculate cables buried in soil?
Yes, you can calculate cables buried in soil if allowed by the selected sizing standard. For example, BS 7671 provides calculation methods for multicore armoured cable buried in soil, but not for single-core. ERA 69-30 and IEC 60502, for high-voltage cables, also allow buried cable calculations.
Note: If you are using a low-voltage single-core AWA cable, BS 7671 does not cover this. Use ERA 69-30 for this cable.