NX Routing vs EPLAN: The Short Version
NX Routing vs EPLAN is not a winner question. EPLAN owns the electrical logic (schematic, wire list, panel). NX Routing owns the 3D path on the mechanical product model. inteliScience builds the handover between the two for transformer and switchgear makers, so wire lengths, harness drawings and BOM come from one connectivity source instead of three spreadsheets.
The Problem: Two Teams, Two Models, One Transformer
A power transformer leaves the plant with a tank, a cooling system, a control cabinet, a tap changer drive and a few hundred metres of wiring between them. The electrical team designs the cabinet and the circuits in EPLAN. The mechanical team designs the tank, piping and brackets in Siemens NX (renamed Designcenter in June 2026; the routing applications are still what everyone calls NX Routing). The wiring between cabinet and accessories belongs to both teams and, in practice, to neither.
That is where the “NX Routing vs EPLAN” question comes from. Rarely because someone wants to replace a tool. Usually because the wire list in EPLAN says 14 m, the harness on the shop floor was cut at 11 m, and nobody can say which model was right.
We see this in plants that already automate the mechanical side with NXOpen (the pattern is written up in NX Open transformer automation). The generator produces tank, radiators and cabinet mounts in minutes. The wiring still takes days, because it lives in a different system with no agreed interface.
What does NX Routing actually do?
NX Routing is the family name for the electrical routing, mechanical routing and harness applications inside Designcenter. It takes connectivity from outside, places connectors and stock in the 3D assembly, routes paths between them, and produces wire lengths, bundle diameters and a flattened formboard drawing. It does not design the circuit. It consumes it.
The official Siemens wire harness design page lists the scope: netlist import from ECAD systems, auto-routing of wires along connector networks, associative spline paths with minimum radius control, wire length and bundle diameter calculation, interference analysis, design rule checking, a flattened model with tie wraps, clips and grommets, and a connection list export back to ECAD. The older NX fact sheet names the import formats: ASCII, XML and PLMXML netlists.
Mechanical routing covers tubes, pipes, conduit, raceways and HVAC ducts, with design rule checks for bend radius, minimum length, connection compatibility and flow direction. On a transformer that is the oil piping to the radiators, in the same assembly as the wiring, which is the whole point.
Siemens keeps investing here. The December 2025 release (NX 2512) added automated cable tray placement and an override for segregation rules between power, control and instrumentation cables, according to the Siemens electro-mechanical routing update. Segregation is a switchgear topic. That release was aimed at people like you.
What NX Routing does not do, and Siemens does not claim it does: schematic capture, terminal diagrams, panel layout. Siemens has its own ECAD line (Capital) for that. In the DACH transformer and switchgear plants we work with, the installed ECAD base is EPLAN.
What does EPLAN cover, and where does it touch 3D?
EPLAN is three products in this discussion, and only one of them overlaps with NX Routing.
EPLAN Electric P8 is the schematic: symbols, automatic wire connecting, numbering and cross referencing, wire and parts lists, terminal reports, cable diagrams, a BOM derived from the schematic. It is the electrical master. Nothing in NX replaces it.
EPLAN Pro Panel is the 3D control cabinet. It builds the layout from the schematic data: wiring ducts, DIN rails, components, drill holes and cut-outs, exact wire lengths inside the enclosure, and the parts, cutting and wiring lists for the panel shop. It exports the 3D layout to STEP, VRML, JT and IFC, and the EPLAN help is honest about the limit: the STEP export writes faceted geometry, analytic surfaces are not transferred. That matters when the cabinet must sit on a bracket in the NX tank assembly.
EPLAN Harness proD is the overlap. It designs and documents cabling on imported 3D mechanical models and converts the 3D design into a flat production drawing. The Harness proD 2024 help lists native import for NX (up to NX 2206 in that version), Solid Edge, CATIA, Creo, SolidWorks and Inventor, plus STEP, JT and Parasolid (import matrix). Designcenter 2606 (June 2026) is the current NX release, so check that matrix before you plan around it. Harness proD is also not one of the three EPLAN Platform 2027 packages (Preplanning, Electric P8, Pro Panel) that launched in September 2026 with Eplan Copilot; it sits outside those packages.
NX Routing vs EPLAN: Comparison by Criterion
The short answer: EPLAN wins every criterion that is about the circuit, NX Routing wins every criterion that is about the product geometry, and Harness proD vs NX Routing is decided by one thing, who owns the 3D model the harness lives on.
| Criterion | EPLAN Electric P8 | EPLAN Pro Panel | EPLAN Harness proD | NX Routing (Designcenter) |
|---|---|---|---|---|
| Schematic and logical connectivity | Master | Reads P8 | Reads wire list | Imports netlist (ASCII, XML, PLMXML); no schematic |
| 3D geometry of the product (tank, frame, brackets) | None | Cabinet only | Imported, static | Native, associative NX assembly |
| Harness outside the cabinet | Cable diagram | No | Yes, on imported MCAD | Yes, in the product assembly |
| Wire length source | Nominal from schematic | Measured inside cabinet | Measured on imported geometry | Measured on the live assembly |
| Flattened harness / formboard drawing | No | No | Flat production drawing | Formboard drawing with connector positions |
| Piping, tubing, cable trays | No | No | No | Yes (mechanical routing, cable trays since NX 2512) |
| Change propagation when the mechanical design moves | Re-import | Re-import | Re-import the model | Associative update in the same assembly |
“Change propagation” is the row that decides. If the tank moves the cabinet bracket by 80 mm, an NX-routed harness updates in the same assembly, while a Harness proD design on an imported STEP needs the import redone. Neither is wrong. They are different answers to “who finds out first.”
When which tool, and how do they work together?
Our clear recommendation: EPLAN authors connectivity, always. NX Routing authors the 3D path wherever the harness is part of the mechanical product. Pro Panel authors the cabinet interior. Harness proD is the right 3D tool when the electrical team owns the harness and the mechanical model is a stable reference, not a moving target.
Four cases for a transformer or switchgear product:
- Circuit design, terminal plans, cable diagrams: Electric P8. No discussion.
- Control cabinet, marshalling box, local control panel: Pro Panel. Export the cabinet as STEP or JT into the NX assembly as an envelope, nothing more.
- Wiring between the cabinet and the accessories on the tank (Buchholz relay, temperature sensors, tap changer drive, fans): NX Routing, fed by the P8 wire list. The paths follow brackets and trays that move with the mechanical design.
- A stand-alone harness built by a supplier from a frozen model: Harness proD, because the mechanical model is a delivery, not a workspace.
Ready to connect the two? How we automate the EPLAN-to-NX handover as an NX workflow automation step, from wire list import to formboard drawing, is described in our NX workflow automation service.
The direction of the data flow is what keeps this stable: connectivity flows from EPLAN into NX, measured lengths flow from NX back to EPLAN. NX Routing has both ends, netlist import and connection list export. The Siemens and EPLAN interoperability announced in December 2024 covers Teamcenter X, TIA Portal, Electric P8 and Pro Panel (Siemens press release); it does not name NX or Harness proD. A wire list that arrives in NX Routing without a person is your own NXOpen tool or an integrator’s connector. Ask which one before the project plan assumes it exists.
We would advise against the fifth case we still meet: drawing the harness twice, in Pro Panel and in NX, with a person keeping them in sync. That is not an integration. That is a second job.
Where does the NX Routing vs EPLAN handover fail in practice?
It fails at the naming and at the change, almost never at the routing itself.
| Symptom | Usually means |
|---|---|
| Netlist imports, but half the connections have no endpoints in NX | Device tags in P8 do not match the port names in the NX reuse library; nobody owns the mapping table |
| Wire lengths in the EPLAN report differ from the harness cut list | Lengths were never exported back from NX; the report still shows nominal values |
| Segregation rule violated on the tray | Power and control cables routed in one run because the netlist carries no class attribute |
| Every order re-routes from scratch | Harness is not templated; the mechanical variant generator ignores routing |
The first row is the most common and the cheapest to fix. Connectivity import works on names. A P8 device tag like =A1+K1-X1:4 has to land on a port in an NX connector part with the same identity. That is a naming standard, not a software feature. We do the mapping once, put it under version control, and the import stops being a weekly surprise.
The last row decides whether routing can be automated at all. If the mechanical generator (a part family, WAVE skeleton or NXOpen tool) produces a new tank variant, the routing has to follow the same rules. Which mechanism should own that variant is compared in NX part family vs WAVE vs NXOpen.
How we set up the interface
A working EPLAN-to-NX interface for a transformer or switchgear line is a short list of agreements plus one automation step. We do it in this order:
- Fix the identity rule: one document that says how a P8 device tag, terminal and pin map to an NX component, port and connector name. Signed by both teams.
- Build or clean the NX routing reuse library: connectors, terminals, stock with diameter and bend radius, cable trays. Every part carries the identity from step 1.
- Agree the EPLAN export: which report, which format (PLMXML or XML in our projects), which filter (field wiring only; cabinet-internal wiring stays in Pro Panel).
- Import into NX Routing on the product assembly, route against topology paths and trays, run design rule checking.
- Export the connection list with measured lengths back to EPLAN so the cable diagram and the cut list agree.
- Generate the formboard drawing and the harness BOM in NX; sync it like the mechanical BOM (the ERP side is covered in CAD-to-ERP BOM sync).
- Wrap steps 4 to 6 in an NXOpen tool that runs per order, so a variant from the mechanical generator gets its wiring the same day.
Step 7 is where most of the value sits and where most teams stop, because it needs someone who knows NXOpen and the routing data model. That is the work behind our NX electrical routing automation case study: the wire list comes from the ECAD side, the paths, lengths and drawings come out of NX without a designer touching each order.
Frequently Asked Questions
Is NX Routing vs EPLAN an either-or decision?
No. EPLAN Electric P8 designs the circuit and NX Routing places it in 3D. The only real overlap is EPLAN Harness proD vs NX Routing for the 3D harness, and that is decided by who owns the 3D model: the mechanical team in NX, or the electrical team on an imported copy.
Can NX Routing import a wire list from EPLAN?
NX Routing imports netlists in ASCII, XML and PLMXML format and exports a connection list back, according to Siemens. No EPLAN-to-NX Routing connector is named in the official Siemens and EPLAN announcements we could verify, so the EPLAN export and the mapping of device tags to NX ports is something you set up or have built.
EPLAN Harness proD vs NX Routing for a transformer harness?
NX Routing if the harness must follow the tank, brackets and trays as the mechanical design changes, because it is associative in the same assembly. Harness proD if the electrical team owns the harness on a frozen mechanical model. Both produce lengths and drawings; only one updates by itself.
Does EPLAN Pro Panel replace NX for the control cabinet?
For the cabinet interior, yes: ducts, rails, drilling, internal wiring and panel shop data belong in Pro Panel. For placing that cabinet on the transformer, no: export it as STEP or JT into the NX assembly as an envelope. The STEP export is faceted, so treat it as a reference, not as geometry to mate against.
How much does an EPLAN-to-NX routing integration cost?
It depends on how clean the naming is, not on the software. The reuse library and the identity mapping are the bulk of the effort; the NXOpen automation that runs import, routing, export and drawings per order is a defined software project on top. We would rather spend a week on the naming rule than a quarter on fixing imports.
Next Step
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