Codes & StandardsWelcome to the source for cutting edge information on PV balance of systems design and installation. Material in this web site is continually updated with the latest Code requirements and with information on the latest installation techniques that are being used by the top installers and systems integrators throughout the country.
This site will not tell you how to size a system, but after the sizing is accomplished, it should provide valuable information on how to connect and install the selected components into a safe system.
A thorough knowledge of the National Electrical Code® (NEC) is required to competently install any electrical power system, including PV systems, in the United States. While there is a specific section (Article 690) of the NEC that is dedicated to PV systems, more than 80% of the remainder of the NEC is directly applicable to PV systems. Anyone using the material in this site should have a copy of the NEC or the NEC Handbook. The NEC Handbook contains the text of the entire NEC plus additional explanatory information and diagrams.
The material in this site is based on the requirements of the National Electrical Code (ANSI/NFPA 70). State, regional, and local codes may impose differing or additional requirements. The local electrical inspector (Authority Having Jurisdiction (AHJ)) has the final say on what is and what is not acceptable.
The information presented in this web site is based on SWTDI interpretations of the National Electrical Code ®, the National Electrical Code Handbook ®, various Institute of Electrical and Electronics Engineers (IEEE) Standards, Underwriters Laboratories Standards, and material from the International Association of Electrical Inspectors (IAEI). Good engineering practices have also been applied.
Some of the material and suggestions are not covered in current codes or standards, but may appear in future editions of the existing documents or in new codes and standards. The material presented is thought to be technically correct. However, the reader is cautioned to use it at his or her own risk. Neither the author, John Wiles, the Southwest Technology Development Institute, New Mexico State University, Sandia National Laboratories, U.S. Department of Energy, or the U.S. Government make any claims to the accuracy of the material included and are not liable for damages or injury incurred from any use of this material.
NEC and NEC Handbook are registered trademarks of the National Fire Protection Association (NFPA). Both documents are available from the NFPA.
PV Power Systems &
The National Electrical Code
John C. Wiles, Instructor