Drawing & Designing
Your project has started. You’ve selected the appropriate template, entered all the project details, added your site image or map, and now it’s time to start drawing your project. PVCAD makes it easy by supplying you with tools designed to draw your site plan, create a layout and specify the appropriate electrical information.
Drawing a site plan
A site plan shows project site dimensions, existing structures and new structures seeking a permit, property line setbacks, and more. It includes mechanical and electrical information, begin by marking the racking area and obstructions.
Roof planes, Ground mount areas, and Obstructions
Go to the Site Objects tab and use POLYLINE to trace your installation area. Make sure to close the polyline by hitting the down arrow key on the keyboard before clicking your last point and then select Close from the dropdown menu. The software will automatically complete your polyline roof plane border.
Select the polyline object you’ve drawn. Back in the Site Objects tab (PVCGEOGRAPHICLOCATION) select the type of object, and tap Define. Once defined, the polyline will be labeled with parameters appearing in the Site Objects tab. Click on the completed polyline border to highlight it and set properties such as height, setbacks from the edge of the roof, slope, and rafter spacing. Hit Enter to update your object parameters. For any defined obstruction, PVCAD will generate the setback line and a shade outline based on height settings. This is important because you want to place solar modules where they maximize exposure to the sun.
PVCAD calculates obstruction shadows based on the project location, roof azimuth, and physical characteristics. You can also adjust how shading is calculated in the Settings tab by specifying the time interval and the season when the calculation is made. Finish defining the remaining obstructions on your roof. If you have multiple instances of the same obstruction, you can use COPY instead of separately tracing each one.
PVCAD is able to product ground mount designs, however, we recommend that for projects larger than 5MWs or single axis trackers you switch to PVCAD Mega. To draw a ground mount, start by using a polyline to trace the outline of your ground mount area and choose “ground mount outline” from the drop down menu. You can then specify and subdivide installation areas within the ground mount project outline. Next, choose your mounting system and modules from the integrated database dropdown, or choose user defined, and specify a table size, row and column spacing. Then PVCAD will generate your layout using either the “fill” or “click and drag” options. You also can populate your layout with tables of different sizes and omit modules from a given table. The String Auto tool allows fast and accurate electrical design, and uniquely numbers every string on your layout.
Creating a Layout
Start on the Version Settings tab to specify system parameters such as conduit height above the roof, source circuit wire size and type, conduit type, and DC/AC ratios. Next, in the Mechanical Layout tab, select system type and racking from the pulldown menus. Based on your racking selections, PVCAD will automatically gray out some fields. This helps to eliminate any confusion as you specify a system type. Finally, choose the module type and click Make Layout.
PVCAD has an extensive collection of manufacturers and products in the module database. If you cannot find a module in the database, see the Troubleshooting section at the end of this guide for instructions on adding a module via your personal database or PVComplete’s public database.
PVCAD provides two options once you select Make Layout. You can fill the roof based on your specified parameters, or you can click and drag to add modules. If you choose to fill the roof, PVCAD will ask which direction the modules will face. Click two points to specify the direction. Then start placing the modules and watch PVCAD fill the entire project area. Sometimes the automated fill function does not place modules in every section where you would like them to go. In this case, click Add Panels at the bottom of the Mechanical Layout tab. Now click a module next to the space where you would like to add modules and drag the cursor into the space to see additional modules appear in a line or across an area of space. Click again to accept the additional modules. When plotting additional modules, PVCAD will not place modules over defined setbacks, shadows, or obstructions. It’s important to use the Add Panels button and never copy and paste modules, because attempting to copy and paste can break the drawing file. Moreover, the Add Panels function always snaps to an existing part of the array, so you don’t have to worry about placing additional modules with absolute precision. The function also allows you to override obstructions, setbacks, or shadow paths, if desired.
Lastly, you can create a layout using tables instead of individual modules. When you add or subtract a module, you’re actually adding or subtracting a table. The PVCAD ribbon has a button to omit modules that removes individual modules in a table and a button to restore, or add back, modules that had been removed. Go to the Summary tab to see how many modules are on the roof and simulate system output.
Electrical properties: Inverter, and Module stringing
Now that you have placed the mechanical components onto the project site, it’s time to select the electrical equipment and indicate how system components will be connected to each other.
In the Electrical Layout tab, select the inverter manufacturer and model from the dropdown menu. PVCAD will provide string sizing suggestions based on the inverter and module voltage selected. You can override this by simply typing in your desired string length under string size. PVCAD will also report how many modules to add or remove for complete strings. Next, add inverters and other electrical equipment to the system layout. Place these wherever you like. You can always move them later. We’ll show you how.
To work with module strings, PVCAD offers three options in the Electrical Layout tab: String Auto, String Manual, and Remove String. String Auto automatically strings modules in the direction you choose – left to right, right to left, top to bottom, or bottom to top. String Auto will not complete a string if the string must change direction. With String Manual, you can type FENCE and then draw a line in the direction of your choosing. Once you’ve selected all the modules, hit Enter to complete the string. Repeat this process for all remaining strings.
Connect strings to inverters and combiner boxes
At the bottom of the Electrical Layout tab, under Draw Conductors, select Source Circuit Conductor to pick the strings you would like to connect. Then click a point where you want the conductors to pass through before connecting. Once finished with all strings, PVCAD will automatically label every wire and tell you how many strings have been connected to each combiner box. Delete any unused combiner boxes. Drag any equipment that needs repositioning, and PVCAD will keep all wires intact. Finally, go back to the Electrical Layout tab and select Output Circuit Conductor to connect combiner boxes and inverters.
Single-line Diagrams
Now it’s time to create the Single-line Diagram. Make sure you’ve followed the steps above and have created your layout, strung your modules together, and connected them to your inverter(s). Also, you must connect the system to an AC panel and one AC panel only. You cannot generate a Single-line Diagram without an AC panel or more than one AC panel.
From the PVCAD ribbon, click the Single-line Diagram button, and PVCAD will generate an appropriately labeled single-line diagram within your CAD file. You can turn the background map off to make the one-line diagram clearer. You can also use MOVE to move the diagram. The single-line is made up of Dynamic Blocks, which makes it very easy to update. Simply select the block you wish to modify and click the triangle to select a different configuration.
The PVCAD Block Library also contains a few other blocks that the single-line doesn’t use, such as a generator, transformers, and battery banks. Depending on the complexity of your system, PVCAD has the blocks that allow you to electrically represent your solar system you’ve designed.
Edit all drawing properties
You can edit drawing properties from anywhere in your current drawing. Start by typing DWGPROPS and hit Enter. A Drawing Properties dialogue box will pop up and you will want to select the Custom tab to access all of PVCAD’s custom drawing properties.
You’ll see that some of the properties are displayed here as well as in the PVCAD sidebar. Scroll down for more properties that you can update, such as revisions, total system size, and total sheets in the drawing set. Once you are finished editing, select OK at the bottom, type REGEN, and PVCAD will apply changes throughout the project plan set.
You are also able to generate multiple layout versions, see the video below for more details!
