How to generate a cable schedule automatically: step-by-step guide

What a cable schedule is and why it matters

A cable schedule is the controlled list of every cable in an installation. It answers the questions that drawings alone cannot: which cable feeds which board, what size and type it is, how it is protected and how long it runs. For a contractor it is a picking list, for a designer it is a check against the single-line diagram, and for the client it is part of the handover pack.

A complete schedule normally carries one row per cable, with columns that stay stable across a project:

The hard part is not the table itself but keeping it true to the design. Once a schedule is typed by hand it starts to drift the moment anything upstream changes, and a schedule that disagrees with the drawings is worse than no schedule at all.

Why generating the schedule automatically pays off

Most mistakes in a cable schedule are copying mistakes. Someone reads a cross-section from the drawing, types it into a spreadsheet, and later the breaker is re-rated or a run gets longer. The table no longer matches reality, but nobody notices until the cables are on site.

Generating the schedule from the same model that produces the diagrams removes that gap. When the single-line diagram, the plans and the panel layouts all come from one model, the schedule is simply another view of the same data:

• A change to a circuit updates every place it appears, not just the drawing.
• Cross-sections and lengths are read from the model instead of retyped.
• The export is always a snapshot of the current design, not an old copy.
• The schedule, specification and estimate stay aligned because they share source data.

Step 1: Fill in the design data once

The schedule can only be as good as the input. Before generating anything, make sure the model carries the four groups of information the table will pull from.

Circuit and load data

Define every final circuit with a clear tag and the load it supplies. Give each circuit a name that survives redesign, such as Kitchen sockets rather than a slot number, and record the connected load so the current can be derived.

Cable and protection data

Set the conductor material, core count and cross-section for each run, and choose the protective device that guards it. These values feed the heating and voltage-drop checks, so they must be present before export.

Route and length data

Trace the route on the plan and let the model measure the length. Route length is what drives voltage drop, so a rough guess here distorts every downstream result.

Step 2: Generate the schedule from the model

Once the data is in, the schedule is generated rather than assembled. Because GorkyCAD builds single-line diagrams, plans, panels and the cable schedule from one model, the schedule appears as a structured table of the same cables you already drew.

1. Open the schedule view for the project or for a single distribution board.
2. Confirm the column set you need for the current stage — design, tender or handover.
3. Let the system pull tags, sizes, devices, lengths and drop results from the model.
4. Review the generated rows and resolve any circuit flagged as incomplete.
5. Re-generate whenever the design changes so the table never lags behind.

You are no longer retyping rows. The job shifts from data entry to review, which is where an engineer's time actually adds value.

Step 3: Export to XLSX and PDF

A schedule has two lives: an editable one for estimating and a fixed one for the document set.

Export to XLSX when the sheet has to travel — for quantity take-off, procurement or a spreadsheet the client already uses. The columns arrive structured, so the rows can be sorted and filtered without rebuilding the table by hand.

Export to PDF when the schedule becomes part of the submission package. A PDF set can bring together the specification, the cable schedule, the estimate and the panel passport in one consistent document, so the reviewer sees numbers that were generated from the same model rather than copied between files.

Because both formats are produced from the live model, the XLSX you send to procurement and the PDF you send to the reviewer describe the same design at the same moment.

Step 4: Verify the data before release

Automation removes typing errors, not design errors. Run a short check before the schedule leaves your desk:

1. Every circuit on the single-line diagram has exactly one row, and no row is orphaned.
2. Cross-sections match the calculated current and clear the voltage-drop limit.
3. The protective device rating is coordinated with the cable it guards.
4. Route lengths look realistic against the plan, not rounded to zero.
5. Tags in the schedule equal the tags on the drawings and the panel labels.
6. Standards applied to the project are reflected in the checks that ran.

Where a value looks wrong, fix it in the model and re-generate rather than editing the exported file. Editing the export only hides the problem until the next change.

Common mistakes to avoid

The same handful of habits break cable schedules again and again:

• Editing the exported XLSX and treating it as the master — the model must stay the source of truth.
• Leaving lengths as estimates so voltage drop is never actually checked.
• Reusing a circuit tag after a redesign, so two rows claim the same reference.
• Marking spare ways ambiguously instead of labelling them as spare.
• Shipping a schedule that predates the last change to the drawings.

Treating the schedule as a generated view, refreshed on every change, avoids all of these at once.

Cable schedule checklist

Before you release the document set, confirm:

1. Every cable in the model appears as one row in the schedule.
2. Type, cores and cross-section are set for each run.
3. Protective devices and ratings are recorded.
4. Lengths come from the routed plan, not a guess.
5. Voltage-drop results are present and within limits.
6. Tags match the drawings and the panel labels.
7. XLSX and PDF exports carry the same data.
8. The schedule was re-generated after the last design change.

Generate it from the model, export it in the format the task needs, then verify it like any other deliverable. The schedule stops being paperwork and becomes a reliable view of the design.

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FAQ

Can I edit the schedule as a spreadsheet?

Yes. Export to XLSX when the sheet has to be sorted or shared. Keep the project model as the master and re-export after changes so the file never drifts from the design.

What should each row of a cable schedule contain?

One row per cable with its tag, type and cross-section, the protective device, the route length and the voltage-drop result. That set covers design, procurement and handover.

Why does the schedule change when I move a route?

Length is measured from the routed plan, and voltage drop depends on length. Lengthening a run can change a result, so the schedule is refreshed from the model after edits.

Is the cable schedule generated from the same data as the drawings?

Yes. Single-line diagrams, plans, panels and the cable schedule are views of one model, so updating a circuit keeps every view consistent.

Related

• Electrical documentation guide
• Panel design guide
• GorkyCAD features
• Pricing and plans