Buried cable calculations.
Buried cable calculations.
(OP)
Where can I find a comprehensive guide to calculate buried cable sizes in conduit,between two transformers 13.8kV, range XFMR1-50MVA, X=25.4%, XFMR2-289MVA at 0.85pf, 1000ft apart and calculate V-drop.






RE: Buried cable calculations.
Location in the world?
Applicable Codes and Standards?
Also, confirm xfmr2 is 289 MVA at 13.8 kV??
The 25.4% X for xfmr1 seems very suspicious also.
If you are in the US, get a copy of the National Electrical Code and also the IEEE Red Book.
RE: Buried cable calculations.
If you are in IEC world the applicable code would be IEC-287. Sometimes the clients are happy with cable sizing calculations based on current capacity for specific laying conditions and applying different de-rating factors which are clearly mentoined and explained in cable manufacturers' catalogues. However if a thermal dissipation calculation is required then you need to consult the relevant standards as mentioned above.
Volts drop is a part of de-rating calcuation. You calculate the maximum length of selected cable size for site conditions for a maximum allowable voltage drop which depends upon the application. A combined voltage drop of 5% is acceptable.
Hope this was helpful