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Automated calculation of intrinsic safety

Standard-compliant intrinsic safety ("Ex-i") with Engineering Base reduces work and errors

Your advantages at a glance

  • Reliable automated calculation
  • Significantly less work
  • No multiple input of technical data
  • Avoidance of input errors
  • Support for identifying the "right" value pairs
  • Automated provision of documentation
  • Two types of calculation are possible:
    • without cabling for early design phases
    • with full cabling and automatic wiring tracking
  • Rapid finding and navigating: proof is directly linked to objects

Challenges

Explosion protection is always necessary when explosive atmospheres are created by gases or dusts. The potential danger is significant. In each production plant, process data is measured and media flows are induced and regulated. The sensors and actuators that are used for this purpose are usually electrically powered, which means that energy is supplied. In explosion protection areas, the circuits must be intrinsically safe, i.e. the available voltages, currents and power must be reliably limited to values with which neither ignitable sparks nor excessively high surface temperatures arise.

Any operator who discloses process-related explosive areas must provide proof of the intrinsic safety of circuits as a prerequisite for an operating licence. The intrinsic safety "Ex-i" has been a proven ignition protection type in I&C design engineering for decades. The user assumes a high degree of responsibility for its calculation when he selects the most suitable option for his particular use from the diverse range of equipment on the market and interconnects it himself. The proof, which is usually conducted computationally, is not as trivial as it is often documented.

In order to comply with the criteria for intrinsic safety, it is not only necessary to consider the individual equipment included within the circuit, but also the complete interconnection and interaction of all equipment involved, including the connection lines. It is best to already prepare the proof of intrinsic safety in accordance with the installation regulations of EN 60079-14 during the planning and design phase. It must include the selection of suitable equipment as well as the test of the selected interconnection.

Solution

©AUCOTEC AG

AUCOTEC's software platform Engineering Base (EB) also maps the measuring and control circuits for the explosive area, both graphically and in the object model. Proof of intrinsic safety is required for each individual circuit.EB is able to provide this proof. The necessary technical data already exists in the article master data or project data and can be retrieved by any user at any time due to EB's central data storage.

The calculation of the intrinsic safety of all tags (loops) in the project is automated by means of an assistant. For each calculation performed, EB creates a report in Excel format, which shows the result and initial data.

The calculation of the tag includes the parameters of the switching amplifier, the sensor or actuator and the cable length. If the cable length is not specified, the maximum possible cable length whereby intrinsic safety is still achieved is calculated.

EB uses the entered values to check whether the intrinsic safety of the circuits exists. Since users assume a high degree of responsibility when selecting the "right" value pairs, EB also supports them with a detailed user manual and help. The ATEX certificate number must be visible for all relevant items of the tag.

If the conditions for intrinsic safety are not met at a tag, the user directly receives a targeted alert, which is documented in a comprehensible manner as a report object. These alerts are noted in the EB project and can then be processed. Furthermore, EB automatically outputs a report indicating unmet intrinsic safety.

Intrinsic safety "Ex-i" proof and ATEX certificates can also be managed in EB as part of the project documentation.

Benefits

The calculation of intrinsic safety in EB significantly reduces the amount of work involved. The technical data of all planned objects, which is then in EB's data model, can be used directly and does not have to be re-entered as usual. This automatically prevents a common source of errors because, up to now, the object data was usually re-entered manually into an Excel list for the calculation. The assistant that was developed for the calculation further accelerates the workflow. EB's Typical Manager enables the calculation to be performed even faster and more conveniently: simply select a loop typical, copy it and have it calculated via "Ex-i calculation".

The automated provision of the required "Ex-i" documentation and its direct linkage in the EB project constitutes an additional benefit. It is not stored separately in document management, but can be easily found by everyone involved without system disruptions.

The proof is an essential part of operator documentation. Due to its integration into the EB project, form and design are automatically consistent in the documentation.

EB's comprehensive information and assistance provide additional support and security.

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