Frequently Asked Questions


At Download you may download the SIMARIS Suite. Afterwards, you can register online in order to be able to install the separate software tools in the "Software" section.


The professional version of SIMARIS design is not free of charge and can be acquired for a nominal charge by contacting your local SIMARIS contact partner from Siemens.

SIMARIS design, project and curves are free of charge. You can download the SIMARIS Suite free of charge and install the separate software tools after one-time registration.


The professional version of SIMARIS design is not free of charge and can be acquired for a nominal charge by contacting your local SIMARIS contact partner from Siemens.


At Download you may download the SIMARIS Suite. After one-time registration you can install SIMARIS design, SIMARIS project and/or SIMARIS curves. 

SIMARIS Suite amounts to approx. 152MB, SIMARIS design approx. 439 MB, SIMARIS project approx. 233 MB and SIMARIS curves approx. 333 MB. The installation time depends on the speed of your Internet connection.


In rare cases, it may happen that SIMARIS design or SIMARIS project cannot be started after setup and an error message will be displayed indicating that Java cannot be started.


During the starting phase of Java, 768MB of non-fragmented memory space must be available. If not, for example, because the memory is used up by other programs, the above error message will be triggered. 

To remedy the problem, please execute the enclosed patch. To do so, download the ZIP file, decompress it and then start the ResetMemory.exe file. Here it is important that the file is executed with administrator rights. Depending on which program causes the problem, choose SIMARIS design and/or SIMARIS project. Click "Install".


The requirement for available memory is reduced to 512 MB. SIMARIS design, or respectively SIMARIS project, can then be started without any problems, however, the programs will perhaps work a bit more slowly, since they now use or have available less RAM.

Please find the system requirements for download by clicking here.

Please find the system requirements for download by clicking here.

A "network installation" is intended for use in a centrally administered computer network. In contrast to a local installation, SIMARIS design or SIMARIS curves cannot be updated online in this case.


However, all updates are also provided for download as installation packages at The respective installation package includes all previous hotfixes and updates referred to the last main version.


To update a network installation of SIMARIS design or SIMARIS curves using the installation package (offline update), please proceed as follows:

  1. Download the ZIP file containing the service pack.

  2. Decompress the ZIP file and save the .exe file on the server.

  3. Run/Install the offline update by starting the .exe file.

In a network installation, the settings made by users and the Favourites saved by them are stored in a Roaming Profile, thus being available to all computers in the network, whereas a local installation just saves this data locally on the user’s computer.


If you are interested in an network installation, please get in touch with your local SIMARIS contact partner.

As a rule, the SIMARIS planning tools can only be executed under a Windows 10 OS, as described in the system requirements for SIMARIS design und SIMARIS project. In order to be able to use the SIMARIS planning tools on a Mc PC or MacBook, you must install a virtual machine with a Windows operating system. With the aid of this system, you can then install the SIMARIS planning tools. However, Siemens does not render any support for such systems, because only setups under a  Windows 10 OS are supported - as described in the system requirements.


The latest generation of the SIMARIS software tools is only available via the SIMARIS Suite. In order to be able to work with the SIMARIS Suite, a one-time registration is neccessary. For this, please open the SIMARIS Suite and click the "Register" button. Fill in the registration form and confirm your registration in the e-mail, which you will receive afterwards. Next, please log into the SIMARIS Suite with your SIMARIS account.

The registration for the SIMARIS Suite is free of charge. Starting from the SIMARIS Suite you can install / open SIMARIS design, SIMARIS project, SIMARIS curves and the SIMARIS Onlien Toolbox free of charge.


The registration of SIMARIS design professional can be performed after purchasing the license by entering the respective authorization code in the registration form. If you are interested in SIMARIS design professional, please contact your local SIMARIS contact partner.

In case you are already using the SIMARIS Suite and have bought the SIMARIS design professional license afterwards, you can enter your authorization code at "Settings". Afterwards, please start SIMARIS design again. 


If you have lost your authorization code for SIMARIS design professional, please get in touch with your local SIMARIS contact. He/she will assist you in getting a new code.

To modify your user data in the SIMARIS Suite, please hover over your user name above and select "Manage user data". You will be lead to your registration template and can do the respective modifications. 

Countries/Languages/Technology Packages

SIMARIS design can be employed in the defined countries.


SIMARIS project can be employed in the defined countries.


SIMARIS curves is available without any restraint.

SIMARIS design is available in the following languages.


SIMARIS project is available in the following languages.


SIMARIS curves is available in the following languages.


We always try to extend our offer – whenever new language versions are added, you will find them here.

The software is only intended for the planning of electric power distribution systems in the states listed under countries.


Electric network dimensioning in SIMARIS design is performed according to IEC standard and DIN/VDE respectively. The installation of the software requires the specification of one of these countries in order to automatically select the equipment according to its local availability and in order to apply local peculiarities. As you can always work in English or the relevant national language, you can, of course, do the planning with SIMARIS design for all listed countries from wherever you are.

The software is only intended for the planning of electric power distribution systems in the states listed under countries.


System planning in SIMARIS project is made in accordance with the relevant IEC or DIN/VDE standard. Software installation requires to specify one of these countries, so that devices and systems can automatically be selected according to local availability and the application of local particularities. Since you can always work with the English language and sometimes also with the local language, you can, of course, create designs in SIMARIS project for all of the countries listed above, independent of your location.

  • Click "Start" on your computer´s Windows task bar and type "Add or remove programs", select SIMARIS design/curves and click "modify". 

  • In the course of the setup process, you will be taken to the step “Select components”. Here you choose the additional countries you want.

  • To install the technology packages for the additional countries you selected, please complete the setup process.

Attention: This setup process only installs the technology packages with the status of the main version. If there is an update in the meantime, you must run the update again, even if you applied the update prior to the post-installation of country packages, in order to bring the newly installed country packages to the status of the current update. This is done automatically during the next program start provided the appropriate update setting was made, or it can be triggered manually using the Help menu > Start Online Update or, by downloading and installing the update package deployed at

  • Open SIMARIS project.
  • Call up the setup using the Extras menu > Localisation.
  • Select the countries you require in the window in which the available technology packages (countries) are displayed and click the "Accept" button.
  • Go through the setup process til the end and then restart SIMARIS project when you are prompted to do so.

Attention: This setup process only installs the technology packages with the status of the main version. If there is an update in the meantime, you must run the update again, even if you applied the update prior to the post-installation of country packages, in order to bring the newly installed country packages to the status of the current update. This is done automatically during the next program start provided the appropriate update setting was made, or it can be triggered manually using the Help menu > Start Online Update or, by downloading and installing the update package deployed at

A country-specific technology package contains devices which are available in the respective country and comply with the applicable standards and accepted rules of good installation practice of that country.


During the setup process of SIMARIS project, you can select those countries relevant to you from a list. This selection also installs the corresponding technology packages of the selected countries. If no country was selected during setup, no technology package will be installed either, so that the above message will be displayed.


But you can always install the technology packages you need later, by restarting the setup process of SIMARIS project and selecting the desired countries in this new setup process.


Such problems do not originate in the SIMARIS software tools, but in the JRE included, which is always kept in the "jre" folder in the setup directory of the installed programs. This folder cannot be updated online. However, users can manually copy an up-to-date JRE into this folder. Another possibility is to delete the "jre" folder completely so that the programs will then draw on the Java version installed on your computer. However, these changes in the setup of the SIMARIS software have not been tested by Siemens.

In order to be able to offer an optimal service and address feedback from our customers, we provide updates and hotfixes that enable you to keep your software always up-to-date. We strongly recommend the installation of the offered updates and hotfixes.

You can find our latest updates and hotfixes respectively here.


You will need administrator rights in order to install this update and hotfix respectively. SIMARIS design should not run, when the update and hotfix respectively is being installed.


For technical support and troubleshooting get in touch with your local SIMARIS contact.

The demo project for SIMARIS design and SIMARIS project can be loaded every time you open the software by selecting this option in the first window which opens automatically.


Furthermore, you can find the demo project using the "Help" menu > Open Demo Project.

Dimensioning and calculation

Depending on the place of installation and the rated current of the power consumer, the relevant standards require additional protection by RCDs.


When choosing a “place of installation”, please observe the detailed explanations given in standards (IEC 60364-4-41 or DIN VDE 0100-410, DIN VDE 0100-701, IEC 60364-7-702) and the exceptions described there in addition to the excerpts from standards as quoted below.

  • Outer zone (outdoors): RCDs are obligatory for final circuits of portable equipment used outdoors up to an equipment load current of 32 A.

  • Wet zone (= rooms containing a bathtub or shower): all circuits must be protected by one or more than one RCD with a rated residual current of max. 30 mA.

  • Inner zone (indoors): RCDs are obligatory for socket-outlets with a rated max. current not exceeding 32 A, which are intended to be used by unskilled, ordinary users and for general-purpose applications.

You can have your entire network or partial networks and individual circuits automatically dimensioned by SIMARIS design. For an optimized dimensioning result, only the operating modes and switch settings freely pre-defined by you are considered for calculation and device selection. SIMARIS design calculates the minimum and maximum short-circuit current from all pre-defined operating modes as a basis for the entire network dimensioning.

Certain circuits are not included in the automatic dimensioning cycle, although the corresponding operating modes for supply were set. I get unexplicable error messages which canot be eliminated. When I call up the quick view for the calculation results ("Tooltip") "Circuit was never closed or supplied" is displayed. This occurs with circuits which I cannot even connect into, or disconnect from supply in the Operating modes dialog.


These circuits are internally disconnected, although they are designed as non-switchable in the Operating modes dialog. Proceed as follows in order to restore the calculation: For individual circuits (loads, couplings), delete these circuits and add them again. If larger subnetworks are affected, please create a new infeed (this is only possible with SIMARIS design professional) and then move the affected subnetwork to the infeed's LVMD. Then redimension this new network automatically and move the affected subnetwork back to its original position. Finally, you can delete the infeed which you created. If this method is not successful, please contact your regional SIMARIS representative.

SIMARIS design only lists the most common transformers with vector groups Dyn1, Dyn5 and Dyn11.


Calculations in SIMARIS design that concern transformer vector groups only use the resistance ratios R0/R1 and reactance ratios X0/X1.


But if the use of other transformers is required, it is possible to specify the impedances or loop impedances of the feed-in system. This equivalent circuit mapping renders an accurate calculation.

In the case of the symmetrical calculation of the load flow and the voltage drop resulting from it, the impedance is determined in the 3 phases L1, L2 and L3 at equal load. To do this, the resistances (ohmic) and reactances (inductive) with the corresponding phase angles sin φ and cos φ are taken as a basis. Based on the nodal analysis, the longitudinal voltage drop – the real fraction – as well as the imaginary fraction – the so-called transverse voltage drop – are calculated based on these impedances and angles.


In the case of the phase-specific or also asymmetrical calculation, the load flow current is determined separately for each of the 3 phases. The compensating currents, which flow towards the source’s star point in TN systems in case of asymmetrical load, are included in the calculation and can be displayed using the tooltip.

Renewable power generation installations or sources are power semiconductor converter systems with a limited short-circuit current.


If, due to too low short-circuit currents, the overcurrent protection equipment located at the beginning of the circuit does not achieve the corresponding break times according to IEC 60364-4-41 or VDE 0100-410 Clause 411.3.2.2 to 411.3.2.4, it must be ensured that the voltage does not exceed 50 V AC and 120 V DC for simultaneously accessible system parts. This may require the installation of an additional protective equipotential bonding.


In case of fault, the switching devices of the overcurrent protection equipment shall further be triggered by the signal of the power generation source, e.g. by means of a voltage release, and disconnected. The objective is to achieve a reliable galvanic isolation of the faulty circuit. Down-regulating the voltage in case of fault by the feeding source with power electronics is not considered a reliable isolation.  

In parallel network operation between distribution transformers and generators, the generator’s loading depends on its generation voltage. This is influenced and controlled by the rotor’s excitation, as well as by the inductive loading or load shedding. To do this, the generator takes over the full load from both sources connected in parallel. 


Using the "Stipulation for parallel network operation", the generator’s loading or the power factor can be simulated. This means that, when the generator infeed power is lower, more load will be taken over by the distribution transformer connected in parallel. When the loading gets lower than the available generator infeed, the generator feeds back into the medium-voltage grid via the distribution transformer.

Due to the additional input parameter x0 in %, the single-phase short-circuit current, which is highest close to the source, is displayed in a more application-oriented way.

Using the fault sequence analysis, a certain location in the network can be examined for faults, short-circuit, as well as shutdown conditions for the protection of persons. The fault location can be determined freely in the network by a mouse click depending on the operating mode.


Especially in meshed networks, these fault locations are fed via different channels, with different impedances and via multiple protection equipment. This can lead to different tripping times for the protection devices subject to the fault current. These tripping times are evaluated and documented with a status analysis sequence over time (status).


In the time sequence, the network components through which fault current does no longer flow due the tripping of the protection device are grayed out.

The displayed tripping times ta (min) refer to the minimum short-circuit currents. With a filter, different outputs of short-circuit currents can be selected.

When changes are made to the electrical equipment during network planning, and other electrical attributes such as impedances, characteristic curves etc. result therefrom, the software always initiates a calculation process in the background.


In large networks, the software performance may suffer due to a high number of data points to be processed. To prevent this, the calculation running in the background can be manually deactivated until all changes have been made.

Power calculation at the electrical consumer is done with constant current depending on the voltages at the circuits/nodes, started by the voltage drop in the network. These voltage-dependent power outputs are displayed in the energy balance view. The electrical power Pn at the consumer is the one that is calculated from the current entered, referring to the rated voltage of the equipment and the given power factor.

In the SIMARIS design versions until SIMARIS design 9, the backup protection is simulated using a special computational process. From version 10, this process is no longer required, thanks to the implementation of the latest backup protection tables.

Handling of the Software

The circuit must be selected with a mouse click. A Copy action can be performed in the following ways:

  1. Press the key combination CTRL+C (Copy) and then CTRL+V (Paste)

  2. Use the relevant commands which are displayed with a right mouse click

  3. Use the Copy/Paste buttons below the menu bar

  4. Make an appropriate selection in the Edit menu

This information cannot be printed directly. Instead it can be copied and pasted into a suitable document (e.g. Microsoft Word), which can then be printed. To do so, first click any point in the quick view of calculation results (don't select anything) and use the key combination CTRL+C to copy the data on display. The data can be included in the target document with the usual Paste options.

In the graphic display of the network diagram, every added load means that the displayed busbar (blue line) gets wider and wider. It may happen that the busbar cannot be represented any more on the paper size you have chosen, or that the busbar view gets confusing.


To divide the busbar in the graphic display, and thus facilitating a clear layout of the network diagram within the selected paper size, the busbar can be divided with the help of the Library element "Group switch".


This means, as soon as the busbar has reached near paper width, or depending which subdivision of the load groups seems reasonable, one or more group switches will be added to the busbar. When making specifications for the group switch (in the window which opens after adding the switch to the network diagram) it is important to select "None" as type of switchgear, both for the upper and lower switching device. For reasons of transparency in the project documentation, such load groups may be assigned the same name as the upstream distribution system. These groups can be moved or rotated in the graphic view according to project needs.


Compared to a through-busbar, this group formation by way of the graphically inserted group switch (but without switching device!) has neither an effect on calculation/dimensioning in SIMARIS design nor on the export for SIMARIS project.


The two project examples each show a distribution system, one without and one with a division into load groups using a group switch.

Cross-references are used in power transmission systems, such as cables and lines as well as busbar trunking systems for power transmission. They serve to arrange one system part (e.g. sub-distributions) in a different location in the sheet or in a different sheet without displaying a line-type connection (e.g. avoiding intersections).


Clicking right on the power transmission system, the connection can be hidden or shown, with the respective cross-reference displayed with arrows.

The different network elements of the network graphic can be displayed in table format via the table function (sources, cables, busbars, distribution boards, switching devices, and consumers).


In table format, the specified elements can be edited later quickly and efficiently regarding their properties. Lengthy searching and editing within the network graphic can be avoided this way.


A "normal switchboard coupling" means a coupling where between the busbar sections it is not possible to add an impedance (busbar/cable). 
When creating this kind of coupling, there is always a new busbar section for the distribution board being generated. A connection between already existing busbar sections is not possible in this case.


In case of "coupling with impedance", an impedance (busbar/cable) is being defined between the busbar sections and it is considered in the calculation. This way it is possible to connect already existing busbar sections in the network diagram. 

A "switchboard coupling without impedance" can be added with the coupling functionality.


As the "switchboard coupling with impedance" is similar to the structure of a sub-distribution board in SIMARIS design , it can be added using this functionality. 

A coupling with impedance can be a changeover unit for infeeding safety-relevant loads. In this case, according to DIN VDE 0100 - 710 (IEC 60364-7-710, modified) the coupling switch must be installed in the main distribution board of the safety power supply. The user must include this in this case correspondingly. The switch in direction of the energy flow din the beginning of the changeover unit, according to DIN VDE 0100-430 (IEC 60364-4-43), serves as short-current-protection for the connection between the general power distribution and the safety power supply distribution.

The coupling symbol for pasting circuits from the SIMARIS design library is used to display a coupling between two busbar sections without impedance with a switching device (practical application, e.g. coupling panel in a main distribution board).


For this, a new busbar section is created respectively, which can be equipped with a feeding source. A connection between already existing busbars like with the distribution function (impedance) is not possible here. 

Medium Voltage

A transformer can be displayed with medium-voltage protection and switching device (LV-switch, HH fuse) and cable on high-voltage side or without these components.

For further processing and handover to SIMARIS project, a medium-voltage switchgear is being generated correspondingly. 

Transformers and generators can be mapped in a voltage range of 3 to 40.5 kV. Dimensioning is performed automatically for the integrated default values which can be selected from the drop-down menu in the Properties window. In case your project requires specific power ratings or voltages, you can enter these values manually. To do so, select the transformer/generator in the network diagram, right-click your selection to call up the Properties dialog and change the "Manufacturer" data field to "Any entry" so that you can then enter the technical data as desired.

It must be kept in mind that this is a combination of switchgear and protective device. To this end Simaris design contains a specific type of switchgear (8DJH).  Protection is rated dependent on the selected switchgear. Different protective devices may also be chosen manually. Proper implementation in practice is up to the planning engineer, whose responsibility is emphasized accordingly in the software.

With regard to the medium voltage level, SIMARIS design only dimensions the transformer outgoing feeders. These feeders are also included in the selectivity evaluation.

Circuit-breaker type L1.1: vacuum circuit-breaker, SI-capable, Ir = 10,000 / M2, ISC = 25 or 50


Circuit-breaker type L2:  vacuum circuit-breaker, not SI-capable, Ir = 2,000 / M1, ISC = 6 or 20


Legend: SI = short interruption; Ir = number of interruptions (break operations); ISC = number of short-circuit interruptions


The neutral network infeed serves to continue calculating an already calculated low-voltage network at a defined position.


Three different versions of input parameters are possible:

  • Short-circuit currents with the corresponding angles
  • Impedances with the corresponding R/X ratios
  • Loop impedance with angle, R/X ratios and the Ikmax/Ikmin ratio

To do this, it is absolutely required to know the described values or to obtain exact information on the same.


The empirically provided default values are not a sound starting point for a calculation. Projects on this basis are generally incorrect. Via the tooltip function, short-circuit values with the corresponding angles can be taken from existing SIMARIS design projects.

The following setting parameters are possible for renewable energies:

  • Apparent power of the converter
  • cos φ
  • type of infeed
  • max. load factor
  • feed power
  • ratio Ikmax to In

The apparent current of the source is calculated by means of the entered apparent power.


The maximum load factor and feed power parameters are proportionally dependent on each other. They represent the converter’s loading similar to the generator infeed. For load tap-off in parallel operation, too, feedback is done into the higher-level medium-voltage grid by means of a distribution transformer.


With converters being sources with a very small short-circuit power, the short-circuit currents to be expected are in the range of the rated currents of these sources. The maximum short-circuit current of this infeed is calculated with the ratio of Ikmax to rated current.


The type of the provided reactive power in parallel operation can be stipulated via inductive/capacitive.

Motors/Motor Starters

Compared with other consumers, motor circuits depict deviating functional traits due to the contribution to the short-circuit current they are feeding back to the fault location in case of a short circuit. In the consumer dialog field, the following options can be selected:

  • Simple motor protection

    Here, a general drive in non-fused technology is selected. 
    Generally, this is sufficient for most application cases, as the system to be used later on is unknown in the planning stage, and only the drive power is known.
  • Motor starter combination

    With this selection, drives are planned which are saved as tested motor starter combinations – protection device (circuit-breaker / fuse) plus switching device for operational switching (contactors / soft starters).
    This application is recommended when a starter combination is to be planned for the drive and when it has to be placed in a cubicle/switchboard to be delivered. The same is true for planning drives with converters.

At present, circuit-breaker-protected and fuse-protected motor starter combinations have been integrated in SIMARIS design. These are tested assemblies according to CA01. Motor starter selection is restricted in terms of voltage to 690 V maximum and in terms of power rating to 250 kW maximum (depending on the selected voltage).

Since the motor starter combinations kept in the database are tested combinations, they are selected automatically in SIMARIS design on the basis of the selected motor power.


If a suitable combination cannot be found in the first step, you have the possibility to use one of the following tables to find out which of the design-tested combinations provided is best suited for your project requirements. After this selection has been made, you can then adjust the data to be selected for this combination in SIMARIS design (type of construction, starting type, coordination type, overload relay and, if applicable, motor power), so that the desired combination can be considered in your planning.


The following tables present an overview of the motor starter combinations kept in SIMARIS design:

The basis for the SIMARIS design calculating engine are the IEC 60909-0 and VDE 0102 standards: Calculation of short circuits in three-phase AC systems for 50 Hz and 60 Hz power frequencies.


Since the output frequencies of converters deviate from the specified frequencies which are relevant to the standard, the calculation and verification rules saved in SIMARIS design are not applicable to the outgoing cables of frequency converters.


The selection of the cross-sections is done based on a cable connection table recommended for converters.


The verifications common for SIMARIS design regarding shutdown conditions, short-circuit protection, voltage drop, or overload protection are not done for these cables.

Network Parameters

The rated current is the basic device value. The permissible current is the value which is affected by the ambient temperature of the device. For example, the rated current is 125 A at an ambient temperature of 60°C, whereas the permissible current is only 120A.

Simultaneity factor gi
The ratio of outputs of all simultaneously operated consumers to the rated outputs of all connected consumers. The simultaneity factor (for distribution boards only) is directly incorporated into network dimensioning (cable cross sections, protective devices, transformer size).


Capacity factor ai 
The load capacity factor indicates to which proportion of the rated power the network is loaded. The capacity factor has no impact on the dimensioning of cables and protective devices for the final circuit. The capacity factor is incorporated into the dimensioning of the higher-level network (cable cross section, protection devices, transformer size).

At first you do have default values for medium and low voltage. If you change them once when working on a project, these changed values are retained when you open a new project in Simaris design.

With the relative operating voltage at the feeding point, different network parameters can be simulated, triggered by voltage changes in the power supply company’s grid.


They affect the voltage drop calculation as well as the load flow / power calculation.


Again, the calculation is done here at constant current, while the changed settings impact the power balance view with regard to the electric power.


In the load flow view, the percentage voltage and voltage difference are changed at the network points.


The specifications U = … % and Sum ∆U = … % refer to the respective relative operating voltage entered at the feeding point.

With this setting, the reference point or starting point for the voltage drop calculation can be determined for the entire network up until the final consumer.


This setting only impacts the calculation or verification, but not the dimensioning. For dimensioning the line system (cables, busbars), the recommended default value of 4 % can be changed within the circuit.


One of the following reference points can be selected in the project default settings:

  • Feeding point (voltage drop of MV cable connection – switchgear/transformer + voltage drop over transformer)
  • Transformer primary terminals (voltage drop over transformer)
  • Transformer secondary terminals

The short-circuit current calculation on the basis of impedances requires initial values. 


When energy is procured from the medium-voltage grid, these values refer to the short-circuit power of said grid. Here, Skmax and Skmin are equivalent initial values for the maximum and minimum short-circuit currents.


These values can usually be queried with the power supply company. In case only one short-circuit power value can be obtained, a value below or above should be selected for the minimum and maximum input parameters, just to be on the safe side.


When procuring energy from the low-voltage network, which can be reproduced by means of neutral network infeed, these values are not used for the calculation.  

SIMARIS design has three main process steps: calculation, dimensioning and verification.


After the calculation of short-circuit and load flow currents, and depending on the stipulated voltage drop at the cable (circuit dialog), the corresponding cable cross-sections for the respective requirement are searched for in the database of the application.


Using the settings for maximum and minimum cross-sections, the cross-sections to be dimensioned are reduced. For reasons of installation (laying, bending radii), 300 mm² should not be exceeded as a maximum cross-section in the low-voltage area.


In order to meet the calculated requirements, parallel cable systems are dimensioned.


The busbar systems used in the project configuration will be tested for thermal short-circuit strength and overload protection. Dynamic short-circuit strength is present if both attributes are fulfilled (see IEC 60364-4-43 Clause 434). Dynamic short-circuit strength is not verified directly.

Providing that this busbar is used for power distribution, the busbar type cannot be changed in an existing project configuration, since there are different tap-off units for all busbar types. Changing the busbar type would thus inevitably result in error messages being returned. If these busbars are used for power transmission only, busbar systems may be altered at any time or you may even replace busbars by cables.

As a rule, LR busbar systems are strictly intended for power transmission only. This is why SIMARIS design only reproduces this kind of application.

No, this option is not provided, since busbar systems must be individually chosen and rated for every project depending on the architecture and intended area of application. The info window, which can be displayed when selecting busbar systems, contains all information relevant for selection. Users must then make their choice themselves based on the prevailing conditions known to them and the information provided for a specific busbar system.


The selectivity evaluation of switching devices or circuits between each other always depends on the direction of the fault current or the power flow.


Since it can only flow in one direction in radial networks, from the source to the fault locations, only one perspective or representation is required (see SIMARIS design V9).


The case is different in ring and meshed networks in which power flows or fault currents take different routes to the fault locations through different impedances (for this, see also the fault sequence analysis).


For this reason, the selectivity evaluation is done by the application depending on the operating mode to be considered. This can be selected in the settings dialog in the selectivity view.


It must also be observed that the selectivity evaluation is done from circuit to circuit (not from switching device to switching device). This also includes circuits or meshes connected in parallel.

Selectivity evaluation is only available in SIMARIS design professional.


If selectivity evaluation is enabled by clicking the corresponding icon on the tool bar above the network diagram, all switching devices on the network diagram will be highlighted by a green, yellow, or grey colour field.

  • green: item is fully selective

  • yellow: item is partially selective

  • grey: item cannot be evaluated

This can be interpreted as follows: The behaviour of device combinations regarding selectivity can only be established by testing. For those combinations marked as fully or partially selective, appropriate testing is available, but not for the items marked in grey.


To obtain an overview of these additional functions, please click here.

Transformers and generators can be mapped in a voltage range of 3 to 40.5 kV. Other third-party equipment cannot be defined or mapped, since verified data of all device combinations applied must be available for the purpose of protective design and selectivity evaluation.

When adding a dummy load, no switching devices or cables/wires are dimensioned within this circuit, but the load still influences the energy balance.

Printer management regarding this problem is not integrated in SIMARIS design itself. Generally, project output of SIMARIS design is created in DIN A4 format (letter size) with the exception of the network diagram in PDF format. For this file type, users may choose the (original) paper size (max. DIN A0 or any paper size) when editing the network diagram.


During Project step 3 - Project Output, PDF file output is then governed by the printer-specific menu and can usually be adjusted as desired from there (compressed to one page, distributed to several pages in original format etc.). The functionality of the printer menu and its operation depends on the actual hardware (printer) and must be handled accordingly.

If 800 mm² was set as maximum cable cross section in the technical settings for low voltage in the “Project Definition” program step, the value that can be selected in the “Network Design” program step depends on other settings additionally defined in the cables/wires properties:

  • Selection of the conductor material: aluminium (the max. cross section of copper cables/wires is 630 mm²)

  • Cable type: single-core cables

  • Selection of installation type: F bundled, F row, G horizontal or G vertical (can only be selected by clicking the i-button near the “Installation type” drop-down box)

If a value less than 800 mm² was already set as maximum cross section in the technical settings for low voltage, despite the other settings made as listed above, the value permitted for selection in the “Network Design” step will be lower in proportion.

When you use SIMARIS design for your project design, you can also consider disconnectors without protective features. They can either be selected when the relevant circuits are created, or they can later be added, when the circuit properties are edited. To do so, the corresponding switching device is selected on the network diagram, so that an appropriate switch (disconnector) can be selected in the Properties section shown below the network diagram on the left.


Since disconnectors do not affect circuit protection or short-circuit protection, they will only be checked for their current carrying capacity and short-circuit strength.


This means that the selectivity diagram will not show any characteristic curves for these devices in the selectivity evaluation routine of SIMARIS design professional. And consequently, there is no colour coding referring to full/partial selectivity on the network diagram either.

To show a legend containing all symbols in SIMARIS design you can download the respective drawing frames. Afterwards you can load them into the program via software menu "Tools" - "Settings" - "Drawing border" and activate them subsequently at "View" - "Papersize" - "Reload frame".


In SIMARIS project, you can map a network comprising about 22 cubicles of low-voltage switchgear if 1GB of RAM is available on your computer, or a network with 30 cubicles in case of 2GB RAM. This information refers to a project, i.e. the cubicles contained in several low-voltage switchgear units within the same project add up. This development is not linear, any further RAM increase does not result in more cubicles being processed. This is due to MS Windows constraints.


In order to increase the allocation of RAM in the software, please set the requirement for the maximum RAM in the "SIMARISproject.ini" file to a higher value. You will find the "SIMARISproject.ini" file in the “Sp2.0” root directory of your SIMARIS software installation. In "SIMARISproject.ini", please change the entry "-Xmx768m" to "-Xmx1024m". This increases the RAM from the default value of 768MB to 1024MB.


If you would like to import larger networks from SIMARIS design, we recommend that you split the network in two parts. If necessary, you can then add the missing coupling in SIMARIS project.


Regarding other plants (medium voltage sections, transformers, busbar systems, distribution boards), there is no restriction as to build up any number of plants comprising any number of cubicles/panels within a project.

Project output app

If you should encounter any problems on your tablet PC when you want to display documents (PDF) relating to your project created with the SIMARIS curves app, please install the Adobe Acrobat PDF Viewer. Displaying PDF documents created with the SIMARIS curves app presents no problems when you use this PDF viewer tool.

Contact partners

Our SIMARIS contact partners will be pleased to help you with any questions regarding the software itself or the project you are currently working on.


They will also support you in regards of the download of the SIMARIS Suite, the registration or the installation of the separate software tools.