COMPLETING DESIGN DELIVERABLES
Design
This is an example walk through of completing the final design deliverables for a project.
Designers should complete all data collection and build the aurora model before coming to this step. This is the same example account from the earlier electrical and structural walk throughs.
First and Foremost, choose your module and inverter on the upper right. As of this publication, we will be using SIL-400HC+ and the IQ8+ for the foreseeable future. Note that the data collection for the general inputs on the left were not shown in this tutorial; you will verify the module and inverter type at the same time as you collect the general customer information.
Next, you'll need to input the circuit quantity. The maximum number of microinverters per circuit is 13. Whenever you have 13 modules/inverters or less, you can consolidate the whole system onto a single circuit. What this is really calling out is the breakers the number of breakers and their ratings for the combiner box.
For example: if we had a 14 panel system, we know we would need to split the system into two circuits landing on two different breakers in the combiner box.
Notice that the AC and DC system sizes will populate in the gray fields below. The DC system size is the total amount of DC power (in kilowatts) that the modules can produce at one time prior to being inverted to AC current for use of the residential electrical system. The AC system size is the net amount of AC power produced by the inverters.
Never overwrite a gray box. We should only be modifying the inputs indicated by white spaces and only when there is accompanying prompt text.
The following inputs will be determined by the structural and layout designs
Homerun Location:
This depends on attic access and logistics which is a judgement that can be made when looking at structural photos
Distance from Farthest Array to Combiner Box
This will be determined during the layout design using the ruler available in aurora modeling software.
Distance from Combiner Box to POI (Point of Interconnection)
In this case, we can default to the minimum distance of 10'. In other cases, where the POI might be indoors away from the meter, you will need to get a good estimate using the ruler in aurora.
Now input the Bus and Main Disconnect ratings:
Notice that the "PV System OCPD Rating" has populated in the box under the "Existing Main Disconnect Rating."
The tool uses the same calculation as we used earlier to calculate the total inverter backfeed. You may utilize the tool during data collection to do this calculation for you if you would like, but it is recommended that you start out doing manual calculations to build good habits.
Now select our chosen interconnection. Don't over think it. As a rule of thumb, if it was simple to come up with the interconnection method, then it is most likely the simplest relevant choice from the drop down.
Load Side Breaker has a number of different options for special circumstances such as:
Split Bus panel
Sub panel options
derate options
Feed through lugs options (protected feeders)
This design is pretty cut and dry, we can use the default "Load Side Breaker" option.
Now select the Make and Model Callout.
Lastly, select if a tandem is needed or not. Remember, tandems/triplexes/quads are only needed if we need to consolidate circuits to make sufficient space for our PV breaker. We need 2 spaces for our interconnection.
On this example, we had plenty of bus space to work with, so no Tandem Breakers will be needed.
Location will be either interior or exterior. The key to this: is there attic access under each array? If yes, then interior.
The distance from farthest array to combiner will come from your data collection. Minimum distance is 40'
The distance from the combiner box to POI will be a minimum of 10'.
This may need to be measured in conjuncture with the farthest array distance if the interconnection load center is interior, away from the meter, and you have an idea of the location.
Now scroll down on inputs to the Layout/Structural Design inputs.
All of this info should already exist in your data collection.
Of note:
Shingle layers are a more critical point on older roofs.
Default to 2 layers on older roofs if the shingle condition is good and the surveyor did not get a photo indicating the number of layers.
On new roofs such as this, you can default to just 1 layer.
Number of Stories at the meter:
This usually just means the total levels of the home as utility meters are usually level grade with the main level of the house.
Occasionally you will see a house where the home is on a hill with a "basement" level that is half underground but emerges from the downward slope.
If the meter is on this part of the home, then that would essentially add another story to the total height from the roof down to the meter.
Notice that the white input field under the roof area has not yet populated a prompt for what info goes there.
This cell is depending on your input for the structural framing type since we selected a hip roof as our roof shape.
When trusses are selected, it will ask for the number of horizontal box truss mounts that will be needed
We will circle back to this.
All of this info should already exist in your data collection as well.
Be careful to ensure that the data used for these boxes matches as they are registered to the roof sections in aurora.
don't modify module count field. This is automatically generated by the racking input above this info.
Remember, for trusses, we can always make it pass calcs. Default to 72.
Now, the Horizontal Box Truss Mount box has appeared. Let's walk through the easiest way to get this number.
First, we need to revisit which roof we flagged for horizontal box trusses. You may need to cross reference your data collection and the shade document to ensure you choose the right roof. On this example, it is RS1.
To get the number of box truss mounts, we need to first fill out only the racking info for this roof section. The row input corresponds to the green box while the columns correlates to the blue square.
Here's the key to it:
Each horizontal row needs it's own racking input.
Most times, you will default the "Row" quantity as 1 and account for each row separately.
The only time you can choose a quantity other than 1 is if you have multiple horizontal rows with the same quantity of modules in the row. If they have differing numbers of modules in each row then each will need a separate input.
On this one, we have 1 horizontal row of 3 modules (or 3 columns).
Think of the "Duplicate Qty" as a multiplier.
This is another way you can duplicate rows when you have identical rows of input.
It is recommended that you always default this field to be a multiplier of 1.
The "Attachment Points" field bellow will begin to populate the needed mounting points and increase as you add more racking inputs. That will be the key to this:
Copy the number that was generated when we input only the racking info for the roof section that has horizontal box trusses and paste the value into the " Horizontal Box Truss Mount Qty"
Make sure to input each row of modules individually.
See bellow for examples of the racking input.
Default the Duplicate Qty to 1.
Always check the Structural Calc statuses below the framing input to ensure that we have all green "OK" Statuses. In this example, we are getting a message stating that we need to request ancillary work for structural blocking. Add this to your data collection so that you will remember to take care of this when you wrap up the design.
While we're here, this is a good opportunity to check your data collection to ensure that everything is addressed so far.
We're done inputting the electrical and structural data. Now we need to check the Utility and AHJ requirements to make sure we are meeting each of their electrical requirements with our current design. To do this, navigate to the "Jurisdiction Requirements" tab at the bottom.
Starting on the right, look at the general requirements. General requirements are requirements that are most common. The page is set up this way so that users that maintain the tool can simply update these fields to be "True/False" in the logic rather than having to manually input requirements like they do with special requirements.
Below the general requirements are the special requirements. These requirements get more specific. We need to check both.
The only electrical requirement listed is for a residential load calc. It is a conditional requirement depending on weather the meter is on a pedestal or not. If the meter is attached to the house, it is not on a pedestal. We can check off this requirement as it does not apply.
This is what a meter on a pedestal looks like:
This doesn't look anything like what we have going on with this project.
Check the General Jurisdiction Requirements for:
Structural stamps needed
What type
After this, we can move on to the Layout and Structural requirements below. These requirements will be more specific.
Make sure to keep any requirement that references a specific plan set page unchecked for the plan set process.
Looks like there's no additional structural requirements. Scroll down to the electrical requirements.
The only requirement listed here is in regards to an ESC. An Electrical Service Change is when the entire MSP (and sometimes the meter as well) need to be replaced due to code violations, extensive damage, or when the panel is insufficient for interconnection. This does not apply to this project, so we can check off this requirement.
Now look at the right column for Utility Requirements.
Leave anything that applies to the plan set unchecked. The top two highlighted blocks give instruction for creating the electrical diagram on the plan set.
Do check off anything that does not apply. In this case, we can check off the battery requirement since this is not a battery account.
Keep Scrolling. Seeing this many requirements can be daunting but you'll find that most of them are fairly simple and easy to address or they do not apply to your specific project.
Let's go through this in order:
Requirement 1: "Do not install meter/main combo panels for upgrades..." This is refereing to when an ESC is needed. We can check this off.
Requirement 2: This appears to be informational and not a real requirement. Let's check this off.
Requirement 3: The very first words of this requirement is "Supply Side Taps," Therefore we know it won't apply to this project since we're doing a Load Side Breaker. Let's check this off.
Requirement 4: Again, this is in regards to Supply side taps. Let's check this off.
Requirement 5: "PV cannot be interconnected in to ANY subpanel..." We're interconnecting in the MSP, so this is already covered. Let's check this off.
Requirement 6: Any time you see a reference to a specific plan set page, in this case P-E9. We'll leave this unchecked for the plan set.
Requirement 7: Again, this gives instruction for one of the planset pages, V-2. We'll leave this unchecked for the plan set.
Requirement 8: Notes like this can be a little confusing. Grab a staff designer or a supervisor to help if you're having a hard time understanding the requirement. This requirement gives two different stipulations. 1. "Cannot have conduit bodies between microinverters and the main service panel..." this applies to existing conduit for the existing service; there shouldn't be conduit obstructing the PV raceways. 2. We cannot use PVC as our raceway, it needs to be EMT and the requirement instructs us how to do it. Let's circle back to this.
Requirement 9: "Meters/equipment cannot be in an area that may become enclosed..." This does not apply. We can check this off.
Requirement 10: "New meters to be between 4' and 6' above grade..." This is a note for the installers. Add it to your data collection sheet for easy transfer.
Requirement 11: "Existing meter socked should be 200A ringless type..." we verified this earlier in the process. We can check this off.
Requirement 8: We cannot use PVC as our raceway, it needs to be EMT and the requirement instructs us how to do it. Navigate to CSettings to change the default selection for exterior raceways.
To do this, simply find the field that corresponds with the instructions in the requirement. Change the raceway type using the drop down. We want the EMT option with the same THWN, AL option (THWN, AL refers to the wiring).
This is how we're looking now with out utility requirements. Everything left here is instructions for completing the plan set, except for the install note. Let's address this now.
Navigate to the Cover Sheet.
Use the template notes from the Final Design SOP and adjust the notes to the criteria of the design to complete this step.
The note regarding the meter height requirement can be tacked onto the end of the electrical note template as found in the SOP for final design.
Adjust the template to fit the criteria for the design and then add the custom note regarding meter height.
Once this is done, you can check off the corresponding requirement.
Start at the top and work your way down:
Design number will be V1-Design for the initial design. Note that this should change for any subsequent revisions.
Today's date.
Annual Usage from our data collection.
System size from our data collection.
Proposal production from our data collection
New production from our data collection.
For the first two drop downs under Design Change Details, use the most relevant option. In this case we're doing:
Production Increase: Less than 10% of Sold
Module Location - Same Roof Sections
The reason for change should only include information that the customer will care about. Don't include a lot of technical information here.
Use the most relevent option from these drop downs. Do not call out upgrades for anything that is not required, for example, if the roof has some spots that need some attention but the overall condition is suitable for install, do not call out a re-roof.
This page gets printed and merged with the final design document from Aurora.