Does anyone know any where I can find texts/paragraphs covering the requirements in terms of burial depths, voltage, etc for underground cables on the DC side. I looked at section 35 of the NESC Code 2007 Handbook as well as the section 300.5 of the NEC 2008 handbook. However, I believe those only deal with AC current. I need similar information but for DC current. Anyone?

Thanks!

Post on Electrical and Lighting site. Stan and TKRussel know code forward and backward.

Thank you hkstroud. I shall post on Electrical and lighting site