EPLAN Auto Wire Numbering: Prefix Follows Device Tag
In modern electrical engineering, especially when designing control panels with multiple variable-frequency drives (VFDs), consistent and automated wire numbering is crucial. Many engineers face the challenge of making wire numbers automatically adopt a prefix based on the device identifier. This article explores how to achieve this in EPLAN, ensuring your schematics remain clear and error-free.
Understanding the Need for Dynamic Wire Numbering
When a control cabinet contains numerous VFDs, each motor connection typically requires a unique wire number that reflects its associated device. For instance, if a VFD has the device tag -U1, you might want all wires connected to its motor output to start with U1-. Manually assigning these numbers is time-consuming and prone to errors. EPLAN offers powerful automation features to link wire numbers to device properties.
Key Concept:
The Connection Definition Point (CDP) is the central element for defining wire properties. By configuring its properties to reference the parent device’s identifier, you can automate the wire number prefix.
Step-by-Step Configuration in EPLAN
Follow these steps to set up automatic wire numbering with a device-dependent prefix:
- Open the Connection Definition Point Properties: Double-click on a connection definition point in your schematic. If you don’t have one placed, insert it from the Insert > Connection definition point menu.
- Navigate to the Wire Number Field: In the properties dialog, find the Wire number or Connection designation field. This is where you’ll define the automatic format.
- Use Property Placeholders: Instead of typing a static number, click the “…” button next to the field to open the formula editor. Here you can insert placeholders that reference device properties. For example, to use the device tag of the connected component, you might use
<11002>(the property ID for “Displayed DT”). The exact property ID can vary by EPLAN version; common ones include:Property Typical Placeholder Description Displayed DT <11002>The full device tag as shown in the schematic Component DT <11001>The device tag without the prefix character Connection point designation <20004>The terminal or pin name (e.g., U, V, W) - Combine Placeholders for Desired Format: To achieve a wire number like U1-L1, you could use a formula such as
<11002>-<20004>. This concatenates the device tag and the connection point designation with a hyphen. - Apply to Multiple Connections: You can copy this formatted connection definition point to all relevant motor connections. Better yet, use the Project data > Connections > Navigator to select multiple connections and assign the same property template.
Advanced Techniques for Large Projects
For projects with hundreds of VFDs, manual placement of CDPs can still be tedious. Consider these advanced methods:
Using Symbol Macros
Create a symbol macro for a VFD motor connection that already includes a pre-configured CDP. When you insert the macro, the wire numbers automatically adapt to the device tag of the parent VFD.
Property Mapping with Scheme
Define a connection numbering scheme in Options > Settings > Projects > “Project name” > Connections > Connection numbering. Here you can set rules that apply project-wide, such as always prefixing with the higher-level function designation.
Practical Example: VFD Motor Wiring
Imagine a control cabinet with three VFDs tagged -U1, -U2, and -U3. Each drives a motor with three-phase connections U, V, W. By setting the CDP wire number formula to <11002>-<20004>, the resulting wire numbers become:
| VFD Tag | Motor Connection | Auto Wire Number |
|---|---|---|
| -U1 | U | U1-U |
| -U1 | V | U1-V |
| -U1 | W | U1-W |
| -U2 | U | U2-U |
| -U2 | V | U2-V |
| -U2 | W | U2-W |
This method ensures that if you later change the device tag of a VFD (e.g., from -U1 to -U10), all associated wire numbers update automatically when you refresh the connections.
Important Note:
The exact property IDs may differ based on your EPLAN version and configuration. Always verify by checking the property number in the status bar when you hover over a property in the object properties dialog. Additionally, ensure that your connection definition points are placed on the correct connection segments to avoid misassignment.
Troubleshooting Common Issues
- Wire number not updating: After changing a device tag, use Project data > Connections > Update to refresh all connection designations.
- Incorrect prefix: Double-check that the CDP is actually associated with the correct device. The connection must be logically linked to the component’s connection point.
- Placeholder shows as text: If the placeholder appears literally (e.g., “<11002>”) instead of being evaluated, ensure that the field is set to “Automatic” or that the formula syntax is correct.
Benefits for Electrical Control Panel Design
Automating wire numbering based on device tags brings several advantages to electrical control panel manufacturing:
Reduced Errors
Eliminates manual typing mistakes
Consistency
Uniform naming across all sheets
Time Savings
Instant updates on design changes
Better Documentation
Clear traceability for maintenance
By leveraging EPLAN’s property-driven wire numbering, you can significantly streamline the design of complex electrical control systems, especially those involving multiple drives and motor connections. Experiment with different property combinations to find the format that best suits your project standards.
