Knowing how to draw a solar SLD is a core skill for installers and designers. This step-by-step guide walks through building a compliant single line diagram, what each part shows, and how to produce one in a fraction of the time.
Before you start
Have your system design ready: panel and inverter selection, the number of strings and modules per string, MPPT allocation, and any battery. You will also need the relevant standard symbols and an understanding of AS/NZS 5033.
Step 1 — Lay out the PV array
Start at the array. Show the modules grouped into strings, with the number of modules per string, and how each string connects to the inverter's MPPT inputs.
Step 2 — Add DC isolation and protection
Add the DC isolators and any string protection between the array and the inverter, as required for the configuration.
Step 3 — Add the inverter
Place the inverter with its key ratings, showing the DC inputs in and the AC output out.
Step 4 — Add AC isolation, metering and grid
From the inverter, show the AC isolation, the switchboard, metering and the grid connection point, so the path from array to grid is complete on one line.
Step 5 — Add any battery storage
If the system includes storage, add the battery and its protection and isolation. Battery systems have their own requirements, covered in our guide on SLDs for battery storage.
Step 6 — Label and check
Apply clear labelling, then check the diagram against the actual design and the current standard. Every element on the SLD should match what will be installed.
The faster way
Drawing this by hand in CAD is slow. Solar Proof's SLD editor auto-populates the diagram from your design, so steps one to five are largely done for you, and you can export a print-ready PDF in minutes.
