I'm going to assume you mean the US Navy, please let us know if this is not correct.
You need to ask the Naval Facilities Engineering Command what codes and standards they enforce on your particular project.
Most of the projects I've done have required compliance with NEC for buildings and NESC for distribution, but there are exceptions -- and there are also many, many specific modifications to these codes that the Navy has adopted over the years.
A clarification:
This is the correct forum to ask NEC related questions. It is just that IEEE is in the forum title to differentiate from the IEC world. Note the forum title also implies the electrical codes issues in the IEEE world, where the electrical code is NEC. NEC is very much recognized and referenced in IEEE standards. It is also true that NEC is published by NFPA but NFPA forum is intended for fire protection related issues (and other non- NEC related questions.
My long-past experience with NAVFAC is that they expect designs to be done per the NEC. This would include 15 kV distribution systems. I have been on bases where old distribution systems would not have met NEC, but I would think anything new would need to meet NEC. But I think it is up to NAVFAC to decide.
Rafiq, thanks for the clarification -- I'm not a long-enough-term member to have caught that.
As for NAVFAQ, I did have a chance to look through the most current design guides -- both NEC and NESC are stipulated in both low-voltage and base distribution system technical documents.
Section 1.4 of Army TM 5-811-1 (also Air Force AFJMAN 32-1080) Title: Electrical Power Supply and distribution says "Paragraph 1-4. Standards and Codes.
Applicable industry codes, standards, or publications referenced will apply to equipment materials and construction covered herein. The minimum requirements of the latest version of NFPA -70, The National Electrical Coce (NEC), and ANSI C2, The National Electrical Safety Code (NESC) will be met and excededed when more stringent requirements are specified and /or dictated."
