AutoCrear

The State-of-the-Art Solution for automatic
Creepage and Clearance Analysis

PROBLEM

Electric assemblies must fulfill strong safety regulations regarding creepage and clearance distances in order to prevent hazards caused by electric sparks. However, these distances depend on many complex aspects and without a software tool, a designer has to resort to manual measurements and rough approximations. This is not only time consuming, but also highly inaccurate and often causes expensive loops in the production pipeline.

Spark

SOLUTION

AutoCrear provides a robust and efficient software-based analysis of creepage and clearance. Based on over 5 years of research, it features novel state-of-the-art algorithms to handle the highly complex metrics of creepage and clearance paths and is capable of processing even large assemblies. This enables a designer to robustly detect and eliminate all safety violations in the early design stage and thus, significantly optimizes the production of electric assemblies.

 

AutoCrear - Solution for Creepage and Clearance

AutoCrear is a standalone tool which combines the entire workflow of a creepage and clearance analysis in a single program:

  •  Applicable for every CAD system
  •  No external data preparation required
  •  Integrated high-performance 3D viewer
  •  Convenient workflow and session management
  •  Automatic generation of an analysis report

WORKFLOW

Import from CAD System (Catia, Solidworks, NX, Creo)

 

In the basic Version, AutoCrear can import STEP files. For each common CAD format, interface extensions are available to allow for a direct data import.

For Creo users, e-laborate Innovations offers free plug-ins, which allow to start an AutoCrear session directly from Creo. The current working assembly is thereby automatically imported.

Assign CTI values

The CTI value is an essential material property for a creepage and clearance analysis. AutoCrear allows to set these values with a few mouse clicks for entire parts or individual surfaces. In the default color mode, the user gets immediate visual feedback of the specified material properties.

Special part types

Some types of parts such as springs or screws have strong degree of freedom with respect to a rotation around their main axis which significantly influences an analysis. AutoCrear can automatically pre-process such parts in order to make the analysis more robust.

Cementations

Whether or not two adjacent insulators are cemented or not has a significant influence on the analysis. In AutoCrear, cementations can be explicitly specified in order to automatically take care of this fact.

Electric nets are sets of conductive parts which carry the same electric potential. Initially, AutoCrear automatically combines all adjacent conductive components to common nets and assigns basic parameters to them. The user has the possibility to specify net names and parameters and to manually combine nets which are not directly adjacent. There are four different net types in AutoCrear, which are organized in separate lists:
  • Potential Potential: the net is supplied with an electric potential. Such a net can act as source as well as target of a creepage or clearance path.
  • Grounded Grounded: The net is explicitly grounded and can act as target of an analysis.
  • Potential-Free Potential-free: The net is neither supplied with an electric potential nor is it grounded (e.g. screws). Such a net can act as intermediate source and foreshorten a path.
  • Touchable Touchable: The net is actually potential free, but can be temporarily a grounded when a person touches it. Such net can act as targets of an analysis and as intermediate sources.
Electric net types Electric net visualization

The analysis engine of AutoCrear must know which distances have to be fulfilled between the net pairs and which groove width should be applied for creepage. This information can be handed to the computation in two ways:

Using Standard Tables

The distance values are usually defined by industry standards and depend on the voltage difference, the used insulation class and the degree of pollution. AutoCrear offers the possibility to define and to apply such standard tables.

Standard Table

Custom Parameters

Alternatively, the distance values can be specified directly between each net pair. This allows to check for individual distances apart from any industry standard.

Custom Parameters

After the previous steps have been processed, an automatic creepage and/or clearance analysis can be started for a single source net or for all sources at once.

The time for a full analysis depends on the size of the assembly and can vary from a few seconds for small or moderate assemblies (< 10MB) up to a few hours for extremely huge assemblies (> 200 MB).

The computation considers all relevant aspects about creepage and clearance paths:

Creepage and clearance currents can take shortcuts through potential-free conductors (e.g screws). This aspect is automatically considered in AutoCrear.

Shortcut
Shortcut throught screw

According to industry regulations, the creepage is allowed to jump for a certain distance. This allows a creepage path to pass a groove if the groove width parameter is sufficient.

Creepage with groove width of 1.2mm Creepage with groove width of 0.9mm Creepage with groove width of 0.4mm

Example: creepage over a 1.0mm groove with different groove width parameters

Forshorten path using groove width

The groove width parameter is not only applied to jump over a groove, but also to foreshorten a path at each possible occasion (e.g. non-convex edges). This aspect makes an exact creepage computation highly complex and is fully considered in AutoCrear.

Results Tab

After the analysis, all paths between the net pairs which fall below the specified distance can be browsed and visualized.
Icons provide immediate visual feedback of the type of violation between each source/target net pairs:

  • Red: Major violation
  • Yellow Minor violation
  • Green No violation
For each possible source-target pair, all paths can be listed in ascending order. On selection, the path is visualized in the 3D viewer and further options are available.

Tags can be manually set for each path to explicitly confirm a violation (Violation), to overrule a violation (OK) or to set a question mark (Unknown).

Comments can be added to a path which are automatically equipped with the date and user name. This allows for a communication about individual paths with other team members.

Comments

In many cases, paths are located deep inside the assembly, covered by several components. AutoCrear offers various features in order to quickly identify such paths. This includes moving the camera position to the start/end point of the path, setting a highlight around the path, automatically hiding components which are not involved in the path or activating a "Path Window".

Path features

Camera positions can be permanently stored for each path in order to ease the repeated browsing of results. Also the stored camera positions are used for the automatic screenshot generation in the documentation feature.

Path Window

Example of a Path Window. A certain section around the displayed path is automatically cut out of the assembly to see through occluding components.

You can automatically create a customizable analysis report from the results, either as pdf or as html document. Beside custom items, the following contents can be automatically included:

  •   A title page including a company logo and general information about the assembly and the analysis
  •   A list of all components of the assembly including a screenshot and the specified meta data
  •   A list of all defined nets with screenshots and assigned properties
  •   An analysis summary listing the analysis parameters for each net pair along with the worst violation
  •   A detailed list of all paths between each net pair including screenshots (based on pre-defined camera positions) and the specified user comments and tags for each path

Documentation
PDF

At any stage of the workflow, an AutoCrear Session file (.acs) can be saved. This file includes all required information to restore and continue the session at any time:

  •   The pre-processed geometry of the assembly
  •   The specified meta data
  •   The electric nets
  •   The analysis parameters
  •   The results

In the end, the session file can be seen as a digital 3D document of the analysis and can be loaded and viewed by any other team member using the free AutoCrear Viewer. The Original CAD data is not required as the geometry is stored in the session file. The cost-efficient AutoCrear Extended Viewer additionally allows to edit the results.

Reuse

Re-use information

If the assembly is changed and re-loaded into a new AutoCrear Session, all the user input from a previous session can be automatically restored and must not be edited again.

BENEFITS

TimeTime

Engineers of electric assemblies spent a significant amount of time to manually measure and document the creepage and clearance paths on their CAD design. Depending on the complexity, this can take several days / weeks. With AutoCrear, the process reduces to a few minutes / hours.

SafetySafety

Manual measurements are not only time consuming but also inaccurate. Violations concerning creepage and clearance distances can be missed, leading to unsafe product releases and possible recalls. AutoCrear avoids this worst-case scenario due to an exact computation of creepage and clearance paths.

QualityQuality

Compactness is often an important quality feature for electric assemblies. However, building electric nets closer together increases the risk of safety violations regarding creepage and clearance. As a result, engineers tend to add too much safety distance between nets. AutoCrear allows to design assemblies as compact as possible without violating the industry regulations.

CostsCosts

In any case, AutoCrear saves the costs an engineer has to spend on manual creepage/clearance measurements and documentations. This saves ~ 2,000 - 10,000 EUR per assembly. If a violation is missed by manual measurements, unnecessary production loops or even product recalls are the result. The costs for such a scenario can run into millions. AutoCrear provides an insurance against this worst-case.

PRODUCTS

Feature AutoCrear AutoCrear Ext. Viewer AutoCrear Viewer
Importing MCAD data + - -
Loading session files + + +
Saving session files + + -
3D viewer + + +
Assigning meta data + - -
Defining electric nets + - -
Performing creepage and clearance computations + - -
Display creepage and clearance paths + + +
Tagging, commenting, deleting paths + + -
Automatic documentation features + + -

INTEGRATION OF AUTOCREAR INTO YOUR SYSTEM

AutoCrear can be purchased as a standalone tool that supports common CAD formats or as a plugin solution for PTC Creo. In addition to the software package we offer an individual integration of AutoCrear into your production pipeline combined with trainings. Furthermore, a clearance and creepage analysis as a service provides you a first introduction to our method. If you are interested in AutoCrear, please don't hesitate to contact us.

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