businessServices
Single-line diagrams built to the NEC and utility standard a permit reviewer and an interconnection engineer both need to see.
Talk to our team
Get single-line diagrams built to NEC and utility interconnection standards. SLD engineering services for solar permitting and interconnection on Sunhub.
A single-line diagram has to satisfy both a local AHJ's permitting checklist and a utility's interconnection engineering review, and drawings here are built to both standards from the start instead of requiring a second version.
Overcurrent protection, disconnects and equipment ratings are documented to the level of detail NEC 2023 and most utility interconnection standards expect.
Structural and electrical stamping requirements vary by state and utility, and SLDs here are stamped to match what the specific project's jurisdiction and interconnecting utility require.
A single SLD built to both AHJ and utility standards avoids drafting two separate versions.
Equipment detail and labeling match what reviewers actually check for the first time.
A permitting SLD needs to show the full electrical path and the equipment on it: modules and their configuration, inverters, DC and AC disconnects, overcurrent protection, conductor and conduit sizing, grounding and bonding, and the point of interconnection. It also needs NEC-compliant labeling and equipment ratings a reviewer can check against code. Exact expectations vary by AHJ, so the drawing should carry the detail a local reviewer requires.
Often they emphasize different things: the AHJ focuses on NEC compliance and safety equipment for the permit, while the utility interconnection engineer focuses on the point of common coupling, protection, and metering. A well-built SLD is drawn to satisfy both audiences on one drawing rather than forcing two separate versions. Confirm each party's specific requirements, since formats and detail levels vary.
A PE stamp certifies the engineering, but a professional engineer can only stamp work in states where they hold a valid license, so multi-jurisdiction coverage depends on the engineer's licensure. A single design can be stamped for several jurisdictions when the engineer is licensed in each and the drawing meets each one's requirements. Where a stamp is required, confirm the engineer's licensure matches the project location.