A single line diagram, or SLD, is one of the core compliance documents in any solar PV installation. If you are an installer, you produce them on every job, but it is worth being clear on exactly what they are and why they matter.
What is a single line diagram?
A single line diagram is a simplified electrical drawing that represents a solar PV system on a single line, showing how the major components connect from the panels through to the grid. Rather than drawing every conductor, it uses standard symbols to show the system's electrical layout clearly on one page.
What does a solar SLD show?
- The PV array, including strings and how they group onto inverter inputs.
- The inverter and its key ratings.
- Isolators and protection, DC and AC isolation, circuit breakers and fusing.
- Metering and the grid connection point.
- Any battery storage and its protection, where fitted.
Why is an SLD required in Australia?
A single line diagram is required documentation for compliant solar installations in Australia. It is used by the installer, the network operator and for STC claims, and it must align with AS/NZS 5033, the standard for PV array installation. A clear, accurate SLD is part of demonstrating the system is safe and compliant.
Who needs to produce one?
Installers and designers produce SLDs as part of the quote and compliance pack. Historically many drew them in CAD software such as AutoCAD or Visio, which is slow. Tools like Solar Proof's browser-based SLD editor generate a compliant diagram from your design automatically, so you are not redrawing from scratch on every job.
The bottom line
A single line diagram is the one-page electrical summary of a solar system, required for compliance in Australia and built around AS/NZS 5033. Getting it right matters, and generating it from your design is far faster than drawing it by hand. Learn more in our guide on how to draw a solar SLD.
