Sizing of underground feeders 1

[EEJaime]

Hello,

We have a project where we apparently have soil conditions which will require us to use a much higher ground ambient temperature to size our feeders. Does anyone out there know of any software or database which includes the calculations for ambient temperatures not in the NEC tables as per NEC article 310 calculations for alternate sizing for non-standard ambient temperatures; sizing of conductors under engineering supervision and for differing component ac resistances; effective thermal resistances, etc...?

Any guidance would be greatly appreciated.

 

[rbulsara]

Visit

http://www.calcware.com/

You need to look up Neher Mcgrath method. You may need various data to fill in the formulas..

Software appears to be best bet..

 

[EEJaime]

Thank you rbulsara, I will look that up. Thanks also for the calcware link, it looks useful.