The problem: the schematic doesn't tell you if the cabinet closes
A well-built schematic in Eplan Electric P8 solves the cabinet's topology: which terminal feeds which contactor, what cable cross-section supplies each output, which breaker protects each circuit. What a 2D schematic doesn't solve is the physical problem: whether 40 DIN-rail modules actually fit on the rail you planned for, whether the door closes once the wireways are full, or whether there's enough clearance to pull a motor starter without removing three other parts first. Translating a schematic into physical space has traditionally been left to the panel builder's judgement on the shop floor.
That works reasonably well for a single, one-off cabinet built by an experienced fitter. It stops working when a project needs ten identical cabinets built in parallel, when design and assembly are handled by two different companies, or when a tender explicitly requires 3D layout drawings as a deliverable. That's where Eplan Pro Panel stops being a nice-to-have and becomes the tool that prevents redesign on the shop floor.
What Eplan Pro Panel is, and why it shares a project with the schematic
Pro Panel is Eplan's 3D design module, and what sets it apart isn't the 3D modeling itself — any mechanical CAD tool can do that — but that it works on the same underlying database as the Electric P8 schematic. Every component placed in the schematic (a contactor, a breaker, a terminal block) already carries its 3D macro, real dimensions, connection points and datasheet, because it comes from the same component data source. Once you move to Pro Panel, that parts list is automatically available for placement in the cabinet — nothing gets remodeled or re-entered by hand.
The usual alternative — laying out the panel in a generic mechanical CAD tool disconnected from the schematic — works fine until someone changes a part reference in the schematic and nobody remembers to update the layout drawing. With Pro Panel, the schematic and the 3D layout are a single source of data: change a component in the schematic and it changes in the 3D model too.
The workflow, step by step
A 3D cabinet design project with Pro Panel always follows the same sequence, whether it's a small control panel or a power cabinet with twenty motor outputs:
| Phase | What happens | Output |
|---|---|---|
| Component import | Devices already placed in the schematic load in as a 3D parts list | Component catalog linked to the schematic, no re-entry of data |
| Enclosure and mounting plate | Choose a commercial enclosure (Rittal, Schneider, Fibox…) or define a custom plate | 3D model of the cabinet shell |
| Component placement | Drag each device onto the plate respecting minimum clearances and functional zones | Draft layout, reviewable before anything is purchased |
| Wireways and ducting | Define the cable paths (slotted duct, tray, harnesses) | Route network available for the auto-routing engine |
| Routing and lengths | The routing engine calculates the actual path of each wire through the defined ducts | Wire list with exact length per connection |
| Collision check | The software compares the 3D volumes of every element against each other | Interference report before any sheet metal is cut |
| Documentation and machining | Generation of layout drawings, labels and NC data | Shop drawings and files for machining equipment |
Component placement: more than fitting pieces together
Placing devices on the mounting plate isn't a packing exercise. A well-thought-out layout accounts for heat dissipation (the components that run hottest — drives, power supplies — need airflow around them and shouldn't sit under a cable harness), separation between power and signal to avoid electromagnetic coupling between power wiring and communication buses, and maintenance access: a motor starter that will need replacing in five years shouldn't require pulling half the terminal strip to reach it.
When a project involves several cabinets for the same machine or installation — common among equipment builders producing repeated control panels by series, like the one in our Siemens control cabinet success story in Valencia — the layout also becomes a reusable standard: the same arrangement, the same terminal numbering and the same ducting convention across every cabinet in the series, which cuts assembly errors and shortens build time from the second cabinet onward.
Automatic wire routing and length calculation
Once the ducts are defined, Pro Panel's routing engine calculates the actual path each wire would take from origin to destination through the wireways and bulkheads — not the straight-line distance a manual calculation would assume. The result is a wire list with the exact length of every connection, ready to cut and label before the fitter even touches the cabinet.
This has a direct impact on the shop floor: instead of cutting wire from a reel by eye and leaving slack at every connection — the usual method in manual assembly — the whole harness can be pre-cut to the correct lengths, which pays off especially when building several units of the same cabinet. The length data can also export to wire-processing machines, closing the loop between design and production.
Catching collisions before anything is built
The collision check compares the 3D volumes of every element in the cabinet: DIN-rail depth against duct depth, minimum cable bend radius against available space, the clearance needed for the door to close once the ducts are full. Any interference shows up on screen as a conflict to resolve, instead of being discovered on the shop floor after the plate has already been drilled.
The value of this check scales with project size. In a tender involving several cabinets subcontracted to different assembly shops, validating the 3D layout before sending out the documentation avoids the most expensive scenario of all: the fitter calling to say the cabinet, as designed, doesn't close.
From 3D model to machine: machining drawings
When the mounting plate needs machining (drilling and milling for cable glands, strain reliefs or brackets), Pro Panel generates the NC data directly from the 3D model, with nobody needing to dimension a drawing by hand for the machine. The same model also exports to DXF for laser-cutting custom plates. This is exactly where design and manufacturing meet: the layout validated on screen is, literally, what the machine cuts at the control cabinet manufacturing shop.
Documentation that keeps itself up to date
The benefit of working from a single database really shows in the final documentation. The bill of materials, the layout drawing, each device's labels and the schematic are all linked: move a component in the 3D model and the layout drawing updates itself; change a reference in the schematic and the bill of materials reflects it without manual intervention. That same bill of materials, with accurate references and quantities, is what reliably feeds an ERP integration for purchasing and stock control, instead of relying on a spreadsheet updated by hand.
Which projects are worth the jump to 3D?
Not every cabinet needs to go through Pro Panel. For a single, straightforward panel with an experienced fitter available, the return on 3D modeling is limited. The jump pays off when one of these applies: repeated cabinet series for the same machine design, tender documentation that requires 3D deliverables or machine-cut plates, projects with a high device and ducting count where collision risk is real, or design and assembly split across two companies, where upfront validation avoids the most expensive back-and-forth in any panel project.
In practice, it's also one of the traits that separates a mature engineering partner from one that only draws schematics — as we explain in our guide on how to choose an industrial automation company, the ability to validate the physical design before manufacturing directly reduces project risk for the end client.
How we do it at Bluemation
At Bluemation we treat the schematic and the 3D layout as a single Eplan project, with our own libraries and macros — both schematic symbols and 3D components — that we reuse across projects, as detailed in our article on Eplan engineering in Spain. When the cabinet also needs to integrate with the controller's programming, we coordinate the electrical data through our TIA Portal engineering workflow so the I/O mapping stays consistent from day one. The result is a cabinet validated on screen, with machining drawings ready for the shop, before the first sheet of metal is cut.
If you have an electrical cabinet project — a single unit or a full series — and want to reduce the risk of something not fitting on the shop floor, check out our Eplan electrical design service or get in touch with us. We'll review your project and recommend the right workflow, with or without 3D modeling.