Electrical design menu
Start by opening the Electrical design menu. The icon can be found in the PVcase Roof mount ribbon.
The Electrical design menu consists of three sections: Inverters, Stringing, and Cabling.
Inverters
Inverter parameters
Before placing the inverter we need to define the parameters of our inverter such as height, width, length, offset, and inverter power.
Inverter placement
After defining the parameters we need to choose where we want to place the inverter. To do so we have several options:
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The inverter is hanging on the building. To place an inverter on the building, choose the inverter placement as "Inside building", add the required measurements, and indicate the inverter’s elevation from the ground in our case we will set it to 7 meters. The last step is to click on the "Add" button, select the location where you want to place the inverter and left-click to place the device. As you can see, the device will be added as a PVcase inverter.
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The inverter is inside the building. To place the inverter inside the building, choose the inverter placement as "Inside building", add the required measurements, and indicate the inverter’s elevation from the ground; In our case we will set it to 7 meters. The last step is to click on the "Add" button, select the location where you want to place the inverter and left-click to place the device. As you can see, the device will be added as a PVcase inverter.
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The inverter is on the ground. When you want to place the inverter on the ground, choose the inverter placement as "Inside building", add the required measurements, and indicate the inverter’s elevation from the ground should be 0 meters. The last step is to click on the "Add" button, select the location where you want to place the inverter and left-click to place the device. As you can see, the device will be added as a PVcase inverter.
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The inverter is on the roof. When you want to place the inverter on the roof, choose the inverter placement as "On the roof", and add the required measurements. The last step is to click on the "Add" button, select the location where you want to place the inverter and left-click to place the device. As you can see, the device will be added as a PVcase inverter.
If you have already predefined outlines of the inverters PVcase will take the length and width of the object, so you will only need to define height, offset, and inverter power. To place the inverter click on Pick from the dwg, select the object and press Space or Enter on your keyboard to finalize. As you can see the device will be converter to a PVcase inverter.
Note: "Pick from dwg" function works for all the methods mentioned above.
Stringing
After placing the inverter now we can open the Stringing menu. To do so click on Stringing.
The first step, even before choosing the stringing type, is to decide if you will be using optimizers. If the Optimizers check box is selected the predefined optimizer configuration will be 2 modules per optimizer.
Stringing types
The next step would be to choose the stringing type that we want to use. In the image, the dot represents the positive pole (+) and the arrow indicates the connection direction and the negative pole (-). PVcase provides 4 options for stringing:
- Single-row stringing
- U-stringing
- Snake stringing
- Custom stringing
Single row stringing
This stringing type will connect the modules in a row, according to specified directions up, down, left, and right.
U-stringing
This stringing type will connect the modules in the U shape, according to specified directions horizontally or vertically.
Snake stringing
This stringing combines 3 types of stringing: single row, U stringing, and zig-zag (snake stringing) patterns. Preference is to create a string with minimum jumps between rows by following other predefined parameters shown in the example below.
Custom stringing
This stringing type will let you draw the stringing according to your needs. When doing the stringing it will show a module counter, which indicates how many modules were already selected for the string. To do so, click on String modules, then you will be prompted to start drawing the string by left-clicking on the modules. To finalize the string, click space or enter on your keyboard.
Note: If you select too many modules while doing custom stringing he can click CTRL+Z and cancel the last selection but continue the stringing process.
Practical example: snake stringing
Let’s take a look at a specific scenario that showcases the Snake stringing type. This stringing type automatically connects modules to maximize the number of modules within strings, based on criteria that you set.
Main steps
First, select the direction; in this case, Horizontal.
Then specify the Modules per string range — the minimum and maximum module amount per string. In our case, we will use a minimum of 20 and a maximum of 24 modules. Based on this setup range, PVcase will prioritize placing the maximum number of strings containing 24 modules.
Furthermore, we must define a Maximum gap between the modules. If the distance is bigger, then the specified distance PVcase will not connect that module to the string. In this case, it will be 4 meters.
Lastly, we need to specify the Module cable length. This is the length of the predefined cables of the module. In this case, it will be 1.2 meters. If the cable length is insufficient, PVcase will automatically add an extension, which will be displayed in a different color.
If you need to avoid crossing safety paths, enable "Avoid Safety Paths when possible" checkbox. We will not use this option.
After all parameters are defined, we can either string specific modules using the String modules function or the whole PV area using the String PV area function. In our case, we will sting the whole PV area. Upon clicking the String PV area button, you will be prompted to select the PV area boundary line, and to finalize press Space or Enter on your keyboard.
Unstrung modules
After the stringing is finished, you might still have some unstrung modules that will be colored red. If you want to string them, you would need to either use Custom stringing or just delete the unstrung modules.
Another option is to combine several patterns on the same drawing by applying different stringing types. Let us first apply a single-row stringing pattern. The steps are the same as before: click the String PV area button, and you will be prompted to select the PV area boundary line. To finalize, press Space or Enter on your keyboard.
There are a lot of modules that could be covered using-U stringing. From the drop down menu select U-Stringing, then click the String PV area button, and you will be prompted to select the PV area boundary line, and to finalize press space or enter on your keyboard. A pop-up window will ask if you want to overwrite the existing stringing or keep it. Choosing to keep the existing stringing will add the new stringing to the unstrung modules.
If you need to remove strings, simply click the Destring modules button. You will be prompted to select the PV area boundary line. To finalize, press space or enter on your keyboard. After doing so the strings will be removed.
Cabling
After placing the inverters and completing the module stringing, the next step is to start the cabling.
Start by opening the Cabling menu.
Inverter configuration
First you need to set up your inverter configuration. For this there are 2 options:
Basic cabling
This inverter configuration is good for the initial design. It will assume that you want to use generic inverters without any MPPT inputs just with a simple string configuration.
MPPT`s connections
This inverter configuration type is good for detailed electrical design, where the user can select the amount of MPPT and MPPT inputs per inverter.
In this example, we will be working with the MPPT connection inverter configuration type. To do so, click on MPPT's connections:
The next step is to define how many MPPTs per inverter we will have. To change the value of the MPPT use the plus sign to increase and the minus sign to decrease the number. In our case, we will be using 10 MPPTs.
After defining the MPPT amount we need to define the number of inputs per MPPT. The process is the same as before: use the plus sign to increase and the minus sign to decrease the number. In our case, we will be using 2 inputs per MPPTs.
After the configurations were set, we can apply the configuration to placed inverters one by one, selecting the inverter from the list and clicking Update SMA1:
Or set the same configuration to all inverters at once selecting the Update all option:
The next step is to assign strings to inverters. We can do that in 2 ways:
One inverter at a time. To assign the string to an inverter select the inverter, then click on select strings after doing so you will be prompted to select the strings, after finishing the selection click space or enter to finalize the selection. As you can see, the selected strings will be assigned to the selected inverter.
All inverters. To assign all strings to an all inverter at once enable the "Connect strings to all inverters at once" check box, then click on select strings after doing so you will be prompted to select the strings, after finishing the selection click space or enter to finalize the selection. As you can see, the strings will be assigned to inverters.
Color coding
If needed you can choose string colors by clicking on the color then choosing the required color and clicking OK to finalize the selection. And if there is a need, you may add more colors by clicking the plus sign.
You can also color the modules that are connected to the inverter. To do so, enable the Color string by inverter checkbox, then click on the color and choose the color. As you can see after doing that the modules will be colored in the specified color.
Other actions
Labeling
You can adjust the naming of your devices. To do so, click on Labeling; a new window will pop up where you will be able to click on any selected name and change it. To implement the changes click on the Update button.
Print MPPTs
As soon as the strings are assigned to the inverters we can print all information about our inverters configuration by clicking on Print MPPTs. Then you will be prompted to left-click and place the table at a desired location to finalize the function.
Print SLD
You can also print the SLD using the same steps as mentioned before. Click on SLD; then you will be prompted to left-click and place the table at a desired location to finalize the function.
Note: If you want to see the cable length on the SLD, export it after the cabling is completed.
Cable trays
Once the strings are assigned to the inverters, you can define the cable trays. These will be used as paths for the cabling. The first step is to configure the cable trays. To do so, click on the Cable tray parameters; a new pop-up window will appear where we will be able to change the height, width, thickness, and segment length. We will leave the parameters as is.
If you are not sure which parameter does what, just click on the field and the parameter will be highlighted in the image on the right.
There are 2 additional checkboxes:
Auto adjust width: If enabled, this function automatically adjusts the cable tray width according to the amount of cables going through the cable tray.
Show cable trays' naming: If enabled, this function will show the naming of each cable tray segment.
For this example, we will enable both functions. After the cable tray configuration is complete, click OK to close the window:
Now we can start drawing the cable trays. To do so, click on Draw cable tray, you will be prompted to draw the cable tray. You can draw it by left-clicking and drawing the cable tray as a simple polyline. To finalize the cable tray, press space or enter on your keyboard. Having done so, the lines will be converted to cable trays.
Note: All cable trays need to cover all modules, and they need to touch each other or cross to avoid any issues when performing the cabling.
Cabling options
After defining the cable trays, the next step is to configure the cabling options.
There are different options to do that.
Auto
All cables for strings will be generated automatically according to the drawn cable trays.
Semi-auto
The semi-auto mode allows the selection of individual strings as well as to specify in more detail the route of the cable. That ultimately forces the software to design the cabling according to the cable trays that are being selected and not the software estimating which ones to use from a handful of cable trays.
Allow cabling to cross safety paths
If enabled, this function will allow for the cable to cross safety paths.
Avoid induction loops
If enabled, PVcase will try to avoid induction loops when performing the cabling as much as possible.
As a last step before starting the cabling, choose the Cable stickiness to the cable tray. If you choose the option the Shortest path, the cabling algorithm is programmed to find the shortest cable route possible. But sometimes the result does not meet the expectations. In that case, you can toggle the cabling algorithm to follow the cable tray more strictly by choosing Stick to tray. This should help keep the cable route within the defined trench lines.
Create cabling
After all cabling options are configured, click on Create cabling and the cables will be created automatically.
You can always remove the cabling by clicking on the Remove cabling button. You will be prompted to select the devices for which you want to remove the cabling. Press space or enter to finalize the action.
To learn how to export the electrical information to the Bill of Materials, check the article Export/import settings.