Bill of materials

The bill of materials — the BOM — is a materials list computed from the layout you have generated. It is a view of the plant: the BOM tab (Ctrl+4) shows the list as a table in place of the plot, every cell in it is editable, and the finished list prints as the Bill of Materials pages of the Detailed Project Report.

It is not a separate document you keep by hand. The quantities are read out of the plant, so a layout that changes and is generated again produces a different list. What you add on top of that — extra line items, corrected descriptions, remarks for a procurement team — is yours until the list is rebuilt, and it is rebuilt both when you ask and after a Generate or a change to the plant's grouping (see What rebuilding does).

The BOM view

Click the BOM tab, or press Ctrl+4. Generate a layout first: the list is computed from a placed plant, and there is nothing to compute before one exists.

The table takes the whole area under the view header. The left column hands its inputs over to a green banner ● Bill of Materials with an Exit BOM button, and under it the BOM TOOLS panel; Exit BOM hands the column back to the stage tabs. The status line reads "BOM Mode ON — double-click any cell to edit. It prints on its own page in the PDF." The view tabs and the tools beside them are described on Views.

The list is part of the session, so it is saved into the project file along with the inputs, the layout and your sketch edits, and comes back when the project is reopened. See Projects.

The five columns

The table has a fixed set of columns, in this order.

Quantity and Unit are deliberately separate. A line counted in numbers and a line counted in metres sit in the same table without ambiguity, which matters as soon as cables and structures appear on the same list.

BOM TOOLS

The panel in the left column holds everything that acts on the list.

The hint under the buttons says what the panel is for: "The main table is the automated BOM. Load Template opens it in a separate window; edit it there, then replace the plant BOM with it (used in the PDF)."

Despite its label, Hide Layout & Energy Summary hides the chip row, not a table. Untick it and the chips come back; nothing is discarded.

What rebuilding does

⚙ Rebuild from Layout is not a refresh that merges. It recomputes the whole list from the current plant and puts that in place of what was there.

The list is also rebuilt without a button and without asking. After any of these, the next time you open the BOM view the list is recomputed from the layout:

• Generate Layout;
• a change on the ACCB & Transformer card (Transformer in a central-inverter design), which regroups the plant — see ACCB and transformers;
• loading an inverter file on a layout that already exists.

That is the behaviour you want in one specific situation and not in any other:

• Rebuild after you have changed the plant without generating it again — added or deleted tables by hand, run the cleaning tool — and you want the quantities to match it. After drawing an obstruction or moving a control room, generate again instead: trench lengths are measured afresh only by a full cable run.
• Do not rebuild once you have started editing the list for real. Finish the layout first, rebuild once, then edit. The order costs nothing and saves the work.

If you need both — a fully edited list and a set of current quantities to check it against — export the edited list to a spreadsheet before rebuilding, then compare the two outside the application.

Editing a cell

Double-click any cell and type. Every column is editable, including the computed quantities — so a figure you overwrite is a figure you own from then on, and it stands until the list is rebuilt.

Three edits are worth making even on a list you otherwise leave alone:

• Descriptions. The computed text is generic. Replacing it with the designation your organisation buys against turns the list into something a supplier can quote from.
• Remarks. Cable specifications, connector types, structure grades and finishes — the detail the layout has no way of knowing.
• Missing line items. Anything the plant's geometry cannot imply. Read the computed list against your own material take-off and add what is not in it.

For a starting point written for a reference plant of the same design, load the built-in template rather than typing from scratch. See Materials list templates.

Where the quantities come from

Two sources, and understanding the split tells you which figures move when you change the design.

The plant's own counts. Everything the layout has placed and measured is already known — the module count, the full and half tables or tracker units, the inverter control rooms, the string inverters or string monitoring boxes, the lightning arresters, the street lights, the piles, and the cable and trench lengths. These are the same figures the Summary view reports, so the two never disagree. See Summary view.

The electrical grouping. Some quantities are not placed on the ground and are derived from rules instead: the AC combiner boxes (ACCBs), the inverter duty transformers (IDTs) and the power transformer at the main control room. The rules are yours, on the ACCB & Transformer card of the Electrical tab. In each ICR block the inverters are shared onto ACCBs — at most 15 per box by default — and the ACCBs onto transformers — at most 4 by default — and a block whose load exceeds the transformer size limit is given more transformers. Each transformer takes the smallest rating in your list at or above its load. The power transformer is the whole plant's maximum AC output × the margin ÷ the derating, rounded up to the next rating in its own list. The inverter file supplies the loads and the low-voltage side, so without one the list carries the counts but not the ratings.

The single-line diagram's automatic build, the Summary view and the cable schedule read the same grouping, so the diagram and the materials list agree on how many of each there are. The diagram never reads this list: editing it, or loading a template, does not change the diagram. See Building a diagram from the plant.

What the list contains

The rows come out in a fixed order. A row whose quantity would be zero is left out altogether, so a short list is not a fault — it means the plant has none of that item.

In the IDT remark the MV figure is the card's MV voltage and the LV figure the inverter file's output voltage.

Design-warning remarks

When the layout breaks a design rule, the row the warning concerns carries a remark starting Check: and is tinted in the warning colour, with the remark as its tooltip. Control-room warnings go on ICR (Inverter Control Room); feeder and voltage-drop warnings on AC Cable (Inverter → ICR) or DC Cable (SMB → Central Inverter); trench warnings on the AC or DC trench row. Several on one row are joined with a semicolon. A warning whose row is not on the list gets a row of its own, Design warning. The remarks travel into the Excel and PDF exports and the report. See Design warnings.

Four things change which rows appear:

• A tracker plant carries Tracker (Full) and Half Tracker in place of the two table rows.
• A central-inverter plant carries SMB (String Monitoring Box) and Central Inverter in place of String Inverter, adds DC Cable (SMB → Central Inverter), and its second trench row is the DC trunk trench — there is no AC leg. See Choosing a design mode.
• Running without cable calculation leaves the string, AC and DC-trunk cable and trench rows at zero, so they drop out.
• Not placing a main control room drops rows 15 to 19, from the switchgear panel down to the room itself.

The cleaning robot fleet

Rows 22 to 24 appear only after you have run the cleaning tool. Run 🤖 Robotic Module Cleaning on the Tools tab, decide which wide gaps you will bridge, and click its Add n robots + m bridges to BOM button. The fleet then feeds both the Summary view's Cleaning robots row and this list. Until you do, there is no fleet on the list at all.

That is deliberate. A cleaning fleet is a purchase decision with a bridge count attached to it, not something a layout implies, so the list never carries a fleet you did not ask for. See Robotic module cleaning.

What the list does not carry

Earthing materials are not in the bill of materials. Earth pits, GI strip, earthing cable and the fittings that go with them come only from the Earthing Design study, whose bill of quantities exports on its own. See Earthing design.

Exporting the list

Two exports on the tools panel, both of the list on screen rather than the computed one — whatever you have edited is what is written.

These are separate from the report. Export ▾ ▸ Export Detailed Project Report, in the view header, writes a Word document that already carries the materials list as its Bill of Materials annexure, paginated across as many pages as the list needs, alongside the drawing, the summary and the diagram — and Export PDF (with Piles) carries the same pages while the pile overlay is on. Use the standalone buttons when you want the list on its own; a purchasing department rarely wants the engineering drawing attached to it. See The Detailed Project Report.

What the list is, and is not

State this to whoever receives it, because it sets what they can do with it.

• It is a materials list, not a priced bill of quantities. There is no rate column, no amount column and no total. Pricing happens after the export, in the spreadsheet.
• The descriptions are generic. They describe the item, not a supplier's catalogue part. Nothing here is tied to a make, a model or a stock code until you type one in.
• It follows from a layout, so it inherits the layout's assumptions. Cable quantities exist only if cable calculation was on for the run; a fleet exists only if you sized one; arresters exist only if you asked for them. A missing row on this list is usually a setting rather than an absence.
• Nothing is checked against a standard. Quantities are counts and lengths, not a verified schedule of material.

A working order

The list is cheapest to produce if the plant is finished before you start editing it.

Where to go next