KoCoS Blog

Combining several disturbance recorders into one device

In the last blog, we looked at combining and overlaying disturbance records from different data sources to evaluate network disturbances across locations. The focus was on manual overlaying of data using the SHERLOG Expert analysis software.

In the current release of the SHERLOG-Expert software, we have now added the ability to automatically merge disturbance records from any number of SHERLOG CRX and EPPE CX devices into a single disturbance record. Since the data is merged within the SHERLOG-Expert software, it does not matter whether the individual devices are installed together in one station or distributed over entire regions.

A single SHERLOG CRX can be equipped with up to 32 analog and up to 128 binary inputs. In many stations, however, there are considerably more signals to be monitored, so that several SHERLOGs are almost always used within a station. In this case, the KoCoS interlink interface ensures that all devices always operate absolutely synchronously in terms of time and that cross-trigger information is exchanged between them for the parallel recording of network faults.


Thanks to the new functionality of the SHERLOG-Expert software, it is now possible to create so-called combined devices and assign any SHERLOG CRX or EPPE CX devices to them. A combined device thus consists of at least 2 or more physical devices. The disturbance records of these combined devices then automatically contain all channels of all assigned devices, summarized in one record.


This method simplifies the handling and the disturbance analysis substantially, since per grid event  only one file must be opened, analyzed or passed on. Of course, it is still possible to access the recordings of the individual physical devices separately as usual.

In the real power supply environment, it is difficult to generate power quality events in order to analyze their characteristics and effects. Therefore, a system is needed with the ability to generate and output diverse three-phase signal waveforms.

With the software-based signal generator system EPOS 360, it is possible to realize an overall system with which three-phase power quality events can be simulated in a simple way.
Three-phase voltage and current signals with different signal disturbances can be generated with the EPOS operating software, such as voltage dips or interruptions, transient pulses and distortion of the voltage or current signal caused by the influence of higher order harmonic components.

Different monitors are available in the software for parameterization and the output of signals and test sequences.


The TRANSIG-Monitor module can be used to check the function of a DUT under real conditions. The TRANSIG-Monitor enables the graphical display and output of recordings and signal curves. Signal curves can be, for example, recordings of fault value acquisition systems or digital protection relays, which are available in the standardized COMTRADE format, or SigDef files with self-defined signals.

The functions of the TRANSIG monitor are:

  1. Loading of recordings in COMTRADE format or SigDef files.
  2. Assignment of the signals of the recording to the EPOS output signals.
  3. Scaling of the signals of the recordings.
  4. Transfer of the defined TRANSIG functions into a test plan.

Signal Editor

Another component of the EPOS operating software is the signal editor. The signal editor enables the definition, parameterization and calculation of any signal characteristics. The parameterization of the signals is done interactively on the screen. A signal duration can be set for each channel and each channel can in turn be divided into any number of time windows of different lengths. Within the time windows different function curves can be synthesized. It is possible to synthesize the function curves from a basic function, such as

  1. sine, 
  2. rectangle, 
  3. sawtooth,
  4. triangle, 
  5. DC

and their additive or multiplicative superposition with one or more superposition functions.

Superpositions can be functions, such as

  1. sine,
  2. exponential functions,
  3. ramps,
  4. DC,
  5. impulse,
  6. harmonics,
  7. mathematical expressions.

In particular, the mathematical expressions in the overlays should be pointed out, since the creation of formulas offers a wide range of possibilities for signal generation. The overlay function "Expression" is used to create a curve using mathematical inputs.


The three-phase signal generator EPOS 360 offers the possibility to create different signal waveforms, to apply them to the test object and to analyze the effects. The overall EPOS 360 system with the EPOS operating software thus provides a useful mechanism to understand and explain network phenomena without much effort.

Do you have questions about the EPOS 360 three-phase signal generator? We have the answers!
Contact us via the comment function here on the blog or by mail to info(at)kocos.com.

Recently, customers have repeatedly asked us about a suitable large display unit for INDEC systems. They would like to be informed about the current degree of processing for the current batch as well as about error messages that have occurred on the large-format vacuum testing system used, which is visible from afar in the production hall. We are pleased to announce the availability of such a large display with an edge length of 63 x 14 cm for INDEC 300 model.

As you can see in the photos below, the counter number as well as the error messages are easily readable from a great distance. This makes it possible for the operating personnel to quickly take the necessary precautions to immediately eliminate the deficiencies in the filling process.


As a rule, the vacuum testing system is not constantly monitored by the operating personnel. If, during the 100 % inspection of all containers, a system error of the filling line or an equipment malfunction of the INDEC system should occur, this shop floor result display immediately informs the system operator.  

Gerald Herrmann
product manager

In addition to the hardware of a test system, the testing software also plays a major role in protection relay testing. Even though simple test tasks can be performed with ARTES test systems without a PC using the integrated operator interface, it is only the combination of hardware and software that provides the full range of functions. The testing software is designed to simplify and automate even complex protection tests.

KoCoS meets these requirements with its ARTES 5 testing software. ARTES 5 enables today’s protection engineers to perform their daily tasks quickly and easily. To this end, ARTES 5 offers a wide variety of features that make testing as efficient as possible. 


ARTES 5 is a database-based testing software. This allows centralized management of all necessary settings as well as results and eliminates the need for manual data management. In addition to a simple folder structure, entire plants including voltage levels and bays can be visualized in the topology. 

For data exchange with colleagues or customers, individual data sets or entire structures can be exported from the database to a file. In turn, the information contained can be viewed and edited without importing it into the user’s own database. 

All in One

With the increasing complexity of protection functions, the testing software must provide the user with more and more new tools. In ARTES 5, these tools are known as monitors, and various monitors adapted to different protection functions are provided. All available monitors are included in the standard scope of delivery and do not have to purchased additionally by the user. Regular updates, some of which include new monitors, are also provided free of charge. 

Of course, the ARTES 5 testing software offers much more. For a detailed presentation of ARTES 5 our specialists are at your disposal. Contact us via the comment function or by mail to info(at)kocos.com

Background: What is a standby mode?

Standby mode is a state of a technical device. It is characterized by temporarily deactivated functions that can be reactivated at any time without waiting - for example, with the help of a remote control. Standby mode is also sometimes referred to as waiting mode or apparent off mode.
Since the electrical device must at least be able to process the control signals, there is a need for the corresponding control signal processing circuit to be active at all times. Thus, the device consumes power even in standby mode. For operation in standby mode, energy worth around four billion euros is required every year in Germany alone.

Less consumption in standby mode due to eco-design directive?

In order to reduce the power consumption for which standby mode is responsible, the European Union passed the so-called “Ecodesign Directive” in 2008. This sets limits for the power requirements of household appliances and consumer electronics in standby mode. In 2013, the regulations, which came into force in 2010, were tightened once again. The German government, under the leadership of the Federal Ministry for Economic Affairs and Energy, transposed the (Ecodesign) Directive 2009/125/EC into German law with the Energy-Related Products Act (EVPG).

By 2020, this should result in EU-wide electricity savings of 72 TWh, which roughly corresponds to the energy supply of 4.5 power plant units (with 800 MW capacity and a realistic full load of about 40% [average full load in Germany from 2015 to 2020: 38.7%]) in this period.

How high is the power consumption in standby mode?

Devices without an information or status display may consume a maximum of 0.5 watts in standby mode. By contrast, electrical devices with an information display - for the time, for example - are subject to a maximum of one watt. For devices with high network availability (HiNA devices) or corresponding functions, a limit of eight watts applies. Other networked devices must remain below a value of two watts since 2019.

This means for the maximum annual power consumption of different device classes with a daily standby duration of 22 hours:

  1. Device without information display (0.5 W): approx. 4 kWh
  2. Device with information display (1 W): approx. 8 kWh
  3. Device with high network availability (8 W): approx. 64 kWh


Energy costs in standby mode

For the three device classes described above, the following energy costs result in standby mode (22h), at an average electricity price of 29 cents per kWh (as of 08/21, including fixed price component and the consumption of an average three-person household of 3,300 kWh/a):

  1. Device without information display (0.5 W): approx. 1.16 euros
  2. Device with information display (1 W): approx. 2.32 Euro
  3. Device with high network availability (8 W): approx. 18.56 Euro

In general, the consumption of one watt in standby mode (24h) costs between 2.57 euros and 3.15 euros per year, depending on the electricity tariff.

Example: Digital voice assistant

Owners of a 1st generation voice assistant can expect the following consumption and electricity costs:

  1. In standby mode, i.e. without a question to the assistant or music playback: 2.8 watts.
  2. In assistant mode, when a question is to be answered: 3.2 watts.
  3. In audio playback with medium volume (level 5 of 10): 3 watts.
  4. During audio playback with full volume - level 10 out of 10: 7 watts.

At an average electricity price of 29 cents per kWh, this results in annual electricity costs of 7.09 euros (24.46 kWh) in standby mode (again for a standby duration of 22h). Two hours of music a day (otherwise standby) results in 9.20 euros.

It gets significantly more expensive for 1st generation assistants with an integrated display. These devices cost between approx. 12 and approx. 19 euros per year. However, a positive trend is that newer voice assistants require less energy, especially in standby mode.

How much money can be saved if all devices are switched off completely?

The amount by which the electricity bill can be reduced if the consumer switches off all appliances and does not merely put them into standby mode depends essentially on two factors: First, it depends on how many household and electrical appliances the respective household owns. Secondly, it depends on how old the appliances are. According to information from the consumer advice centre, an average around 10 to 20 percent of electricity consumption is attributable to devices in standby mode. This percentage range has also been observed in power and energy measurements carried out by KoCoS Engineering GmbH, with up to 20 simultaneous measurements using KoCoS EPPE measuring devices, in large properties belonging to the federal states, the federal government or the real estate industry.

The insurance industry assumes an annual savings potential of 330 to 660 KWh for a three-person household. Assuming an electricity price of 29 cents per kWh (see above), this corresponds to a savings potential of approx. 95 euros to approx. 190 euros per year.


After charging the smartphone, the charger remains in the socket?

You probably know this: after charging the smartphone, the charger remains in the socket. It is convenient to be able to simply plug in the smartphone cell phone when needed and not have to search for the charging cable. What does this convenience cost us?

Modern chargers must not consume more than 0.3 W according to the Ecodesign Directive. If we again assume a duration of 22h in standby mode, a consumption of 2.4 kWh, again at an electricity price of 0.29 euros/kWh, results in a cost of 0.70 euros per year.

For each one a small amount. But if you extrapolate the additional costs to the total population, the sum is surprisingly high: because in Germany, around 60.7 million people will be using a smartphone in 2020 (source: statista).

Assuming all location devices of these smartphones remained connected to the grid in standby mode, this would result in an annual consumption of more than 145 GWh or 145 million kWh at a cost of approximately 42 million euros/a. When converted to electricity (2020 energy mix), this results in more than 58 tons of C02 emissions per year (source: UBA).

As mentioned above, a German household with three persons consumes on average about 3,300 kWh per year (as of September 2020). The energy required for standby mode could supply around 44,000 three-person households in Germany with electricity for a year. But even the chargers of laptops, tablets or e-readers consume energy when left in the socket.

In vehicle construction, the dimensional accuracies between the parts of the drive or the entire drive train play an important role for the vibration behavior on the vehicle. Especially at high speeds and torques, deviations from the nominal values become noticeable through noises and vibrations or, in the worst case, through malfunctions and lead to quality loss or even total breakdown.

It is therefore necessary to check an increasing number of geometries for their exact dimensional accuracy. In addition, established tactile measuring methods and inspections using tracing gauges can no longer cope with the required production cycle times in view of the increasing number of dimensions to be inspected.

The degree of automation required in modern production facilities demands fast and fully automated component inspections that are directly integrated into the production process.

With LOTOS 3D measuring systems, drivetrain components can be inspected quickly and reliably for dimensional accuracy. Furthermore, the parts can be classified and sorted directly into different tolerance zones.

For this purpose, the test parts are placed on the measuring system either manually by hand or fully automatically via robot. Automatic quality inspection is then performed for both external and internal dimensions using predefined measuring programs.

This can be, for example, the geometric inspection of a drive shaft: (LOTOS Video)

Cross-location analysis of network disturbances

Merging and superimposing disturbance records from different data sources is a common practice in the analysis of network disturbances. For example, the effect of network faults at different locations, even across several voltage levels, can be clearly displayed, evaluated and documented.

The SHERLOG analysis software from KoCoS has mastered this superimposition since the first generation. Thanks to the globally standardized COMTRADE data format for disturbance recordings, the superimposition even works across manufacturers and devices. Thus, recordings from different disturbance recorders, digital protection relays and power quality monitors with disturbance recorder function can be very conveniently and quickly transferred to a common recording.  


The results of the superposition are as better, as more precisely the individual data sources are time-synchronized. Time deviations result in phase errors. For example, a time deviation of only one millisecond results in a phase error of 18° in 50 Hz networks. In 60 Hz networks even 21.7°.

The first choice for disturbance recorder systems with the highest time accuracy requirements is therefore synchronization by means of GPS time telegram and second pulse or alternatively via the communication network by IEEE 1588 /IEC 61588 standard (PTP). The time deviations in these systems are in the nanosecond to microsecond range and thus practically do not generate any phase errors (<0.1°). 

However, it is very popular and widespread to realize the time synchronization with GPS time servers, which send the time information via the communication network (LAN) using the NTP protocol. This usually results in deviations of between 0.2 and one millisecond in local networks. In distributed networks (WAN), deviations of up to 10 milliseconds are even possible.

With time synchronization using DCF 77 receivers, deviations of 5 to 15 milliseconds are to be expected.  

Basically, it can be stated that the time deviations due to different synchronization methods in practice may well be up to 15 milliseconds. Added to this are even greater deviations due to faulty or completely missing synchronization.

To cope with this situation, KoCoS analysis software offers efficient methods for reliably and quickly compensating for existing time differences between data sources, thus enabling detailed and correct analysis.

Incidentally, the SHERLOG and EPPE measuring systems from KoCoS ensure that time differences between individual devices cannot occur in the first place. The internal GPS receiver or the optical and electrical inputs for connection to external GPS sources synchronize the systems exactly.

But even when using a time source with larger deviations, such as DCF-77 receivers or SNTP, the master-slave principle ensures exact time synchronization between the devices via KoCoS's own interlink interface. Although there may be an absolute time difference due to the accuracy of the time source used, all the devices connected via the interlink interface run absolutely synchronously.


This method ensures perfect overlapping of disturbance records at all times. Even in the event of a total failure of the time source used.


The comparison of actual test systems shows that the technical data of the devices from different manufacturers are similar in many points. And there are specifications where the devices differ to a greater or lesser extent. When evaluating, however, it should always be questioned what this means for the practical use of the devices.

Specifications as a result of development

In some cases, the technical data are much higher than required by the application. And this was not always the aim during development. Rather, some values are just the result of the development, quasi what has come out.

USPs without added value

And there are certainly manufacturers who deliberately work towards generating "unique selling points", which in the end, nobody needs. A real USP only becomes more important when the existing advantages also offer added value and a special benefit for the customer.

Technical data does not tell the whole story

Technical data are easy to compare. But purely numerical values say not much about which product is best suited for the customer. Product features and properties that cannot be evaluated with numbers, or only with difficulty, often lose their importance in the comparison. And it is often here where the advantages can be found that offer real added value for the customer.

Real USPs are not easy to find

The special features of our ARTES testing systems are pointed out in brochures, articles or blog posts. Customers appreciate, for example, that ARTES can be operated in an upright position. The status LEDs in the front or the operation of our devices on DC supplies are also appreciated by many users.

These properties and the many features and functions of ARTES are often not known. For example, the internal control unit, the low-level outputs, the analogue inputs, the multifunctional inputs or the internal GPS synchronisation unit are already included in the standard scope of delivery of the ARTES 600. In competing products, these features are often found, if at all, as options for which a charge must be paid. ARTES also scores points, for example, with its very low noise level, a feature that is difficult to express in numbers.

The software matters

The software plays a major role in relay testing. The device hardware of a test instrument is primarily a freely programmable function generator. Even though ARTES offers much more with its on-site operation, the test software in the end makes a decisive contribution to the high functionality of a professional testing system.

The ARTES 5 software is not only convincing because of its many useful features. It also has the most advanced user interface and the most intuitive operating concept. With ARTES 5, the user reaches his goal faster and easier, and thus saves time. In a following blog post, we will focus on the features and advantages of the ARTES 5 testing software.

ARTES experience live

The special features of ARTES are also highlighted regularly in social media such as Facebook, LikedIn, Twitter or YouTube. However, a live demonstration also offers the opportunity to find out what a customer's requirements and needs are. Only then is it possible to work out the features of ARTES that are important for the customer and to demonstrate their benefits.

Particularly in view of the diverse functions of the software, we are always pleased to offer our customers practical product presentations. Here, the customer not only learns a lot about ARTES, he can also experience ARTES live.

Automation in the field of low-resistance measurement is increasingly required in the factory or laboratory. Be it in the automotive/electromobility sector, in the investigation of soldered or welded joints of high-current connections or in a wide variety of other applications.

For special requirements, e.g. for use in test stands, the easy-to-use PROMET PI programming interface is available for control and measurement with the PROMET R300/R600 resistance measuring devices. This can be used in COM/ActiveX-supporting as well as in .NET environments.
By programming the measurement sequence once, it is possible to integrate the PROMET R300 or R600 resistance measuring instruments into the test equipment via the programming interface and to perform measurements automatically.

A driver is installed with the programming interface, via which the connected devices are addressed. Communication between the software/PC and the external PROMET R300/R600 is made possible by the installed ActiveX component. This allows communication via USB or Ethernet interfaces.
As an example, an Excel sheet is used to control the PROMET R300/R600 and to evaluate the measurement results in this description, via which the programmed VBA macros (Visual Basic for Applications) are executed. Programs can be modified and adapted according to the requirements.

The PROMET R300/R600 precision resistance meters are an ideal tool for characterizing components for high current and low resistance due to their four-wire measurement and ability to accurately measure both current and voltage. 
As demonstrated in the article, a resistance measurement system controlled via external software can be easily integrated into an automated application. Using the PROMET R300/R600 resistance measuring instruments to perform such measurements simplifies the test setup, reduces programming time, and enables efficient test sequences.

Further information on the use of the PROMET PI programming interface can be found in the application report PROMET R300/R600 - The intelligent way to measure resistance!

Do you have any questions about resistance measurement or our measuring devices? Then contact us via the comment function here on the blog or by mail to info(at)kocos.com.

The EPOS 360 three-phase signal generator can also be integrated into your own test applications in a similar form via the EPOS PI programming interface!

Thanks to the excellent, semi-automatic self-learning procedure for determining the sensor parameters (recipes) of the INDEC vacuum inspection systems, commissioning is possible without a KoCoS technician.

Ensuring the highest product quality is a primary and indispensable objective, especially in food production. The tightness of the product containers are an important role in this.

Leaks can cause the contents to leak out. But it is much more important that germs penetrate the container and spoil the product.

The INDEC vacuum testing systems monitor the tightness of containers fully automatically directly in the production process. A wide variety of containers such as bottles, jars and cans are checked for leaks without contact and defective containers are removed from the product flow.

Often, the necessary technician charges for commissioning, especially in Europe or overseas, are not in good proportion to the purchase price of an INDEC system. Sometimes these costs amount to another 30-40% of the purchase price for the equipment.

For this reason, it is very important to have good and meaningful documents such as the operating instructions and suitable videos. We have all those resources in good quality with the INDEC vacuum inspection system.

To make the start easier for the customer, we offer to send us some bottles and jars from his range. We already save predefined sensor parameter sets (recipes) in his ordered INDEC device ex works. If fine-tuning is still required, this can be completed between the end customer and us using modern communication media.

This has already been proven several times in the past, both in Germany with the company STANGL, in the EU with the French company ANDRESY and overseas with PRINCES TUNA in Mauritius. These screen shots illustrate the self-learning process.

The system automatically adjusts the threshold to distinguish between good and bad containers. The more containers are fed to the tester, the more representative the result is for a good separation of good and bad containers.

Due to the excellent, semi-automatic self-learning procedure for determining the sensor parameters (recipes) of the INDEC vacuum testing systems, it is possible for the customer to commission the system on his own. The use of a KoCoS technician or a technician from our local representative on site is not mandatory.

When we talk about "P L C" at KoCoS, we don't mean the programmable logic controller but our various ACTAS test systems. But why does KoCoS offer three different ACTAS product lines?

Quite simply! KoCoS serves the entire mechanical switch testing market with its three different ACTAS product lines. Starting with fully automatic routine testing at the switchgear manufacturer, through the service technician to the test laboratory. The requirements of the various applications can only be optimally met with different devices.


Use of the ACTAS test systems


ACTAS Portable           Service Technician (manual testing)


ACTAS Laboratory       Test laboratories, production, development (semi-automatic testing)


ACTAS Cabinet            Test laboratories, production, development (fully automatic testing)

However, the situation is quite different when it comes to testing software, where an end-to-end solution is important:

With ACTAS 2.60, all tests can be performed with all ACTAS test systems. This is essential in order to be able to reuse tests and test results throughout the entire life of the switchgear. It is then possible to test a switch with ACTAS from the start of its development through to its use in the field, e.g. under using the same templates. For example, the test parameters and limit values developed in the laboratory with ACTAS L can be used directly during routine testing as part of the quality assurance process with ACTAS C. With ACTAS P, the service technician is then also able to access the original parameters during maintenance.

Almost all major switchgear manufacturers, test laboratories and also service technicians appreciate this and take advantage of the great ACTAS benefit of being able to use measuring instruments flexibly for the various applications and to fall back on existing data.

Any questions or additions to the topic? Then please use the comment function here on the blog or send an email to cstuden(at)kocos.com.

In practice, the value of the maximum short-circuit current "Isc_max" of a transformer is often needed. On the one hand, to be able to estimate the current carrying capacity of input circuits, such as in the KoCoS fault recorder system SHERLOG. It must also be taken into account that typical protection current transformers used in medium voltage can transmit currents up to 40 times higher than the rated current of the transformer in the event of a short circuit. On the other hand, a typical application is the plausibility check of the parameters of the high current stage of a transformer protection relay during the commissioning or repeat protection test, for example with our relay test system ARTES.

The following formulas are used to estimate the maximum short-circuit current "Ik_max" for three-phase medium-voltage transformers. The determined current value "Ik_max" is in practice somewhat higher than the real short-circuit current "Ik_max_real" which actually occurs. The estimation is therefore made to the "safe side".

The following equations 1 and 2 show that the estimation can be done for the primary as well as for the secondary side. When using equation 1 and equation 2, it should be noted that "usc" must be entered as a percentage in the equations for the relative short-circuit voltage.

If the rated current of the transformer is not explicitly known (for example, only “Srated_transformer” and “uk” are often specified in network calculations for transformers), the tailored quantity equation 3 can be used. Note: This estimation of the maximum short-circuit current applies only to three-phase medium-voltage transformers with a secondary voltage of Unom_sec = 400V. Also, when using equation 3, note that the relative short-circuit voltage "usc" in percent must be inserted into the equation.

When transformers are used, they are often referred to as "voltage-stiff" or "voltage-soft" transformers with regard to the behaviour of the secondary voltage during load changes. Equations 1 and 2 show that the maximum short-circuit current increases with decreasing "uk" (voltage-stiff) and the maximum short-circuit current decreases with increasing "usc" (voltage-soft). The short-circuit voltage “Vsc” and thus also the relative short-circuit voltage “usc” are a measure of the internal resistance of the transformer.

Voltage soft: When loaded, the output voltage of the transformer decreases. The output current hardly changes. The transformer is short-circuit proof (example: welding transformer).

Voltage stiff: Under load, the output voltage of the transformer hardly decreases. The output current increases. The transformer is not short-circuit proof.

As an aid to remembering the behaviour of the transformer's output voltage, a very hard and a soft cushion can be used. If the same amount of pressure is applied to a very hard and a soft pad, the hard pad is depressed significantly less than the soft pad. The depth of the indentation on the cushion is synonymous with the behaviour of the output voltage of the transformer.

Inspection of tube geometries with LOTOS 3D measuring systems

Precise inspection of various processing steps in tube manufacturing is gaining enormous importance. On the one hand, it is important to automate processes, on the other hand, it is indispensable for a cost-efficient production to detect rejects as early as possible.
If defects are only detected during the final inspection or even after delivery to the customer, they lead to extremely high costs.
The requirements for accuracy and fast, process-reliable inspection, up to 100% inspection of the components directly in production, are constantly increasing.

The LOTOS 3D measuring systems are used both for quality inspection of the tube pieces and for process control and defined alignment for the next processing steps.

Thereby LOTOS systems check for example:

  1. Geometries from cross-sectional contours through to free-form surfaces
  2. Positions and geometries of holes and laser cutouts
  3. Length, straightness, perpendicularity and flatness of the tube pieces
  4. Processing states of tube ends, such as chamfers or fillets of tube edges
  5. Correct alignment to a defined position based on geometric features

Redispatch 2.0

Electricity network operators are required by the Energy Industry Act to ensure the security and reliability of the electricity supply in their network.

Redispatch refers to interventions in the generation output of power plants in order to protect line sections of the electricity network from overload and avoid bottlenecks. If there is a threat of congestion, certain power plants are instructed to reduce their feed-in capacity. At the same time, other power plants must increase their feed-in capacity. This balance-neutral control creates a load flow that counteracts the bottleneck.

Due to the steady growth of renewable energies, whose feed-in capacity is also largely determined by the weather and is subject to strong fluctuations during the course of the day, grid operators have to carry out redispatch measures more and more frequently. 

Previously, redispatch was only carried out with conventional large-scale power plants of 10 MW or more.

With the new Redispatch 2.0, all generation plants with a generation capacity of 100 kW or more, as well as smaller plants that can already be remotely controlled by the grid operator, will also be included in this control process on a mandatory basis. This also includes many decentralized CHP, wind and photovoltaic plants. 

The aim is to increasingly use even more accurate forecast data for predictive grid control in order to ensure grid stability and avoid bottlenecks. In addition, decentralized EEG plants are often located closer to the bottleneck to be resolved and can therefore be deployed in a more targeted manner. This reduces the control services required from large power plants and helps to lower costs in the overall system.  

When Redispatch 2.0 comes into force on 01.10.2021, operators of affected generation plants will be obliged to regularly provide comprehensive data to the grid operator. This includes, among other things, the live measurement data of the plant, which the grid operator can use to determine the power reserve available to it on the basis of the average power value of the past 15 minutes and use it for redispatch. This data is also used to determine possible compensation payments. 

But it is not only the power data that is of interest here. The applicable technical connection rules for power generation plants in medium and high-voltage networks VDE-AR-N 4110 and VDE-AR-N 4120 additionally prescribe the monitoring of voltage quality according to EN 50160 Class A as well as the high-resolution recording of network disturbances.

The measuring systems of the EPPE and SHERLOG product lines fully meet the requirements. Permanent power quality measurements, transient disturbance recordings as well as real-time measurement data transmission and visualization are performed in parallel and independently on these systems.  

Voltages and currents are recorded with a temporal resolution of 200 kHz and a measurement deviation of maximum 0.05%. The resulting data is stored fail-safe in a 32 GB ring buffer and transmitted via cable or LTE/G5-based network connection or can be read out directly at the device via USB interface. The remote data transmission can be time or event controlled. Thus, for example, a detailed fault report including the fault type, fault duration, maximum values that occurred, fault impedance and fault location can be automatically generated by the associated Expert software just a few seconds after a fault occurs and sent to operations management, e.g. by e-mail. Voltage quality reports can also be generated automatically and stored as PDF reports. Real-time measurement data can be read out via MODBUS or IEC 61850, for example, and visualized on all common browsers and platforms via the integrated web server.

Resistance measurement with PROMET - Thanks to Ohm!

After Alessandro Volta created a source that supplied electric current in 1801 with the so-called Volta Column, it was possible to explore the effects of electric current. Many researchers made numerous discoveries and observations, but the mysterious effects of electric current could not be revealed.

It was only through the discoveries and research of Georg Simon Ohm that the facts could be explored. Without his research and without the resulting fundamentals of Ohm's law, the outstanding developments in electrical engineering would not have been possible.

Georg Simon Ohm, born March 16, 1789 in Erlangen, died July 6, 1854 in Munich, was a German physicist.

The decisive measuring instrument for the discovery of Ohm's laws was the torsion balance galvanometer constructed by Ohm. The torsion balance galvanometer consists of a thermocouple (A) in which the ends are kept at different but uniform temperatures (B). A magnetic needle (C) on an adjustable suspension (D) and a device with which the various test conductors (E), i.e. the variable resistance, can be contacted.

If a test conductor is connected so that a current flows, the magnetic needle is deflected. The position is read off a scale. The deflection or the read scale values form a proportional measure for the magnetic effect of the electric current, thus the current intensity.

Ohm was able to deduce the law from these measurements:
I = Uq / (Ri + Rv)
Current = Source Voltage / (Internal Resistance + Variable Resistance)

Ohm published his results in 1826 and initially received little recognition. It was not until 1841 that Ohm received the Copley Medal of the Royal Society of London, which corresponds to today's Nobel Prize, as an award for his work. In 1893, the World Electrical Congress in Chicago gave the designation "Ohm" (sign Omega: Ω) to the unit of electrical resistance.

With Ohm's torsion balance galvanometer, only the first step in the development of resistance measuring instruments is described in this article. The history of resistance measurement shows the changes from the age of early experimenters to today's computer age, i.e. from measuring bridges to the first electronic devices to today's digital measuring systems. Developers always used the latest ideas and systems to make the products more useful and user-friendly. Technological change drove the development of measuring instruments and realized technological advances.


KoCoS is committed to this development and offers a diverse range of resistance measuring instruments with the PROMET series. PROMET precision resistance measuring devices are used to determine low-resistance in the μΩ and mΩ range. With adjustable test currents of up to 600 A in conjunction with a four-wire measuring method, the systems provide measurement results for the highest accuracy requirements. Typical applications are, for example, the determination of the contact resistance of switching devices and the resistance determination on inductive loads such as transformers. The use of state-of-the-art power electronics and the robust design guarantee maximum reliability for mobile use, but also for stationary use in the laboratory and factory.

Do you have questions or additions to the resistance measurement or to our measuring devices? Then contact us via the comment function here on the blog or by mail to info(at)kocos.com.

Reliable operation of all INDEC vacuum inspection systems under the most difficult operating conditions such as vibrations of the conveyor belt.

The vacuum inspection systems of the INDEC series offer our customers a reliable solution for leak testing of jars, bottles and metal cans even under extreme operating conditions. The inspection takes place contact-free as a 100% in-line inspection directly in the production process. An optical sensor detects the vacuum-induced deformation of the lids. Even non-metallic container closures can be inspected. Containers with insufficient vacuum, crooked or missing lids are reliably detected and can be separated fully automatically from the product flow with an ejector. All components are made of stainless steel (1.4404), are resistant to cleaning agents and disinfectants and meet the requirements of protection class IP69K.

How do vibrations of the conveyor affect the reliability of INDEC systems?
We are often confronted by our customers with the question of whether the INDEC systems still function reliably when the conveyor belt is vibrating. This question can be answered with an unequivocal yes.
For this purpose, we would like to refer again to the measuring procedure and the mode of operation of all INDEC systems. The test procedure is based on the determination of the vacuum-induced deformation of the passing container closures. The tightness of the containers is assessed by comparison with a previously “Golden” sample. If a container to be inspected interrupts the light barrier under the sensor head, an infrared light beam is emitted by the sensor head and reflected by the lid of the container.  A sophisticated algorithm calculates the concave shape (yellow curve between the two red arrows, see the figure below measuring principle) of the deformed lid caused by the vacuum in the head space. Depending on the given boundary conditions, vacuum tests are possible from
50 µm deformation or from 150 mbar differential pressure in the headspace to the external pressure.

To illustrate the correct operation of the INDEC models even when the conveyor belt is vibrating, see the following video. From 0:34...0:50 min, artificial vibrations are triggered on the sensor head - analogous to vibrations of the conveyor belt - the INDEC system continues to work correctly in that only when passing the opened bottle marked with the white tape does the signal lamp briefly light up for a container without vacuum.  

Link: cloud.kocos.com/index.php/s/9gkyCKcps5g3rpk

Avoid product recalls even before the goods leave production - with reliable vacuum inspection systems from KoCoS.

A look inside the switchgear chamber "Dynamic Timing" and "Dynamic Resistance

In contrast to evaluation via a simple binary signal, as is the case with high-frequency measurement methods, the use of switchgear test systems ACTAS in combination with resistance measuring devices PROMET allows a well-founded diagnosis of breaker units throughout the entire switching process. The result of the measurement is displayed in the form of a curve in which all events of a switching operation can be seen in detail. An exact assessment of the start of movement and end position of the contacts is thus made possible, even time differences between the movements of the main and resistor contacts become visible.

Evaluation of the breaker unit by means of contact resistance analysis

Regular measurements of the static and dynamic contact resistance allow precise statements to be made about the condition of the entire contact system. Necessary maintenance work can thus be detected at an early stage and downtimes prevented. With the PROMET SE resistance measuring device, contact resistance measurements can be carried out on up to 12 or more interrupters and directly integrated into the overall test sequence. The test current can be set up to a maximum of 200 A. Even very small resistances in the single-digit microohm range can be measured with extremely high accuracy. The measured values are included in the evaluation of the test and output in the test report.

A high contact resistance within a switching device leads to a high power loss, combined with thermal stress and possible destruction of the switching device. Faults, such as high contact resistance due to defective connections, can be detected by measuring the static contact resistance. With the dynamic contact resistance measurement, the resistance curve is determined during a switching operation that can be defined as desired. The measurement allows, for example, conclusions to be drawn about the length and condition of arcing contacts in high-voltage switches.


Any questions or additions to the topic? Then please use the comment function here on the blog or send an email to cstuden(at)kocos.com .

Answer: Nothing! Because when we talk about GOOSE at KoCoS, we usually don’t mean the animal but the network protocol I protection technology. Further answers to the question of what GOOSE is all about and what role the latest ARTES update plays in this context can be found here. 

The IEC 61850 standard of the international Electrotechnical Commission (IEC) describes, among other things, a general transmission protocol for protection and control technology in medium and high voltage substations (station automation). One topic of this series of standards is the “Generic Object Oriented Substation Events”, in short GOOSE messages. 

But what is the significance of these GOOSE messages in a substation? 
In simple terms, GOOSE messages are used to exchange information such as status messages or excitation signals between the IEDs (Intelligent Electronic Devices) of the station. These information are distributed as an Ethernet packets via the process bus of the substation.

With an update to follow in the next few days, the test systems of the 4th ARTES generation can also be integrated into a corresponding environment to evaluate these signals. Thanks to the powerful signal processor of these test systems, they can be connected directly to the process bus, so that the evaluation of GOOSE messages can take place in real time.

Since a large number of GOOSE messages can be present in a network, but only the information of individual ones is of interest for the protection test, the exact structure of the required GOOSE message must be known. For the correct parameterization of ARTES test systems, a relay-specific configuration file is required. This file contains all information regarding the structure of the GOOSE message and its content. The ARTES 5 software analyses the configuration file and the desired signal can be selected. 

After the appropriate parameterization has been carried out, a GOOSE message can perform the same functions as the already used hardware inputs of the ARTES test systems.

Still questions? Then please use the comment function here in the blog or send an e-mail to bfleuth(at)kocos.com

Quality assurance by geometric measurements increasingly becomes important not only in the final inspection. The control of dimensional accuracy is progressively shifting to the beginning of the manufacturing processes in order to detect and minimize rejects at an early stage.
The 3D measuring systems LOTOS are suitable among other applications for the exact measurement of ingots, which represent the beginning of the production process of semiconductor wafers. In order to obtain the optimum yield of wafers from the ingots, a highly accurate geometry determination at the beginning of the manufacturing process is more important than ever.

High-precision measurements of the ingot are critical to the quality and productivity of the wafer cutting process. Only an exact geometry allows to set perfect cuttings.

A solution using mechanical measurements is possible, but very susceptible. The material is very brittle, so mechanical impacts can easily cause micro cracks invisible to the human eye. These lead to wafer breakage in later process steps and thus to cost-intensive rejects.

The advantages of geometry inspection of ingots with LOTOS 3D measuring systems are:

  1. Less waste and scrap of the expensive materials
  2. Optimal utilization of the cross-sectional area of the ingot increases productivity
  3. Contactless measuring method allows a solution without mechanical stress of the material, micro cracks due to mechanical stress are therefore excluded

The following video shows the measurement of an ingot with LOTOS


As well as the scan result as 3D visualization


A network calculation is always necessary when new networks are created or planned, existing networks are revised or new plants as well as consumers have to be integrated into existing networks. Especially in the case of existing networks, a reliable simple statement about the utilization of the network is not easily possible in many cases due to the insufficient data situation. The structures, which have grown over the years, are usually only documented schematically and were, if at all, considered mathematically in parts during refurbishments.

As a result, the security of supply can be endangered. In order to ensure security of supply, it is absolutely necessary to know the load and disconnection conditions in one's own network. These data serve as a basis for the design of network changes.
The network calculation serves thereby:

  • To support the network operation in the evaluation of the current network condition (ACTUAL condition).
  • To support secure network operation by means of forward-looking network simulations (planning basis).
  • As a basis for operational and network expansion planning (TARGET condition).
  • In detail, the network calculation records all dimensioning and calculation data for the correct dimensioning of the electrical power distribution, such as:
  • Utilization of the resources by load flow calculation,
  • Determination of the capacity reserves of the individual resources,
  • Short-circuit current calculation,
  • Voltage drop calculation,
  • Selectivity consideration
  • Current carrying capacity,
  • Protection against overload,
  • Protection against short circuit,
  • Protection against electric shock by disconnection.

In the planning phase of an electrical switchgear or an electrical network, the network calculation is an essential tool for the correct design and the correct selection of the electrical equipment. After completion of the installation, the network calculation is used to determine the setting values of the protective devices or for the required proof of selective fault disconnection (selectivity) in accordance with the applicable standards. The testing of the individual protection devices can of course be carried out with our protection relay testing system "ARTES".

The KoCoS Engineering & Services team uses the established and manufacturer-independent network calculation program "PowerFactory" from DigSILENT. Hereby we calculate nationwide for our customers’ medium and low voltage networks in the automotive industry, industrial and public network operators, public state and federal properties and the petroleum industry.

The European power grid dealt with major problems on 08 January 2021. An entire region in Eastern Europe was disconnected, and in some cases experienced power outages. The European power grid is part of the critical infrastructure (CRITIS). The Austrian Federal Army had already warned in January 2020: "A Europe-wide blackout is to be expected within the next 5 years!“
On 8 January 2021 at around 14:05, a frequency deviation of around 250 mHz occurred in the synchronized European high-voltage electricity grid. As a result, the region of south-eastern Europe was disconnected from the European interconnected grid.

A cascade of failures of equipment, such as power lines and switchgear in south-eastern Europe, led to massive problems within the European power grid. According to the report, the near-blackout in large parts of Europe was triggered by a transformer station in Ernestinovo, Croatia. Initial investigations stated at 14:04 an overcurrent protection device on a 400-kilovolt bus bar coupler in the substation tripped, causing it to switch off automatically. This also interrupted two extra-high voltage connections that carry electricity from the Balkans to other parts of Europe; affecting the lines to Žerjavinec (Croatia) and Pecs (Hungary) in the north-western direction. The result was that within less than 50 seconds the European power grid split into two areas: the northwest, which lacked 6.3 GW of generation capacity, and the southeast, which had a corresponding surplus.

In some regions there were visible problems. For example, lamps in households and on the streets have lit up or went out, and electrical appliances turned on and off. The radio station RFI România reported power cuts in parts of Romania. The frequency drop led to consequential disturbances at various infrastructure operators, such as the Vienna airport and hospitals, which triggered the emergency power supply. There was also a serious incident at Vienna Airport, where hundreds of hardware parts were destroyed and damage amounting to several hundred thousand euros was caused. Approximately one hour after the disconnection, the two power grids were resynchronized.

Exact sequence of the disturbance
At 14:05 (CET) the frequency in the north-western power unit dropped to 49.74 Hz. After about 15 seconds, it stabilized at 49.84 Hz, which is still within the permissible band for deviations of plusminus 0.2 Hz. At the same time, the frequency in the south-eastern area jumped to 50.6 Hertz before stabilizing at a value between 50.2 and 50.3 Hz.

The disconnection of the sub-grid had a clear impact on the grid frequency. Thus, at (14:04:55 local time CET), the grid frequency dropped from about 50.027 Hz to a minimum of 49.742 Hz within 14 seconds. This left the normal control range of 50.000 Hz ±200 mHz. The first stage of the schedule (activation of power reserves) was achieved. Reconnection to the interconnected grid at 15:08 CET, on the other hand, had no effect on the grid frequency.

Reduction of product recalls and costly image damage through the new product feature ejector monitoring at INDEC 300 systems

Avoid product recalls even before the goods leave production - with the reliable vacuum inspection systems from KoCoS.

With our INDEC range of vacuum inspection systems, food manufacturers have the assurance that HACCP (Hazard Analysis & Critical Control Points) principles are met.
KoCoS vacuum inspection systems are characterised by their superior detection sensitivity and automatic rejection of defective products in the food industry.

The ejector monitoring function checks whether the ejector has separated a container from the product flow that has been detected as bad. For this purpose, another light barrier is arranged parallel to the conveyor belt opposite the ejector. If the light barrier is not interrupted by the bad container within the adjustable delay after the ejector has been triggered, an error message is generated.

Call up the Edit Ejector screen - tap the Monitoring button, set it to ON and enter the manually determined delay. In addition to the error message, an electrical switching signal can be output via a binary output, for example to stop the production process automatically.

The costs incurred by executed recalls, such as publication of warning messages, transport back to the factory and loss of sales, are relatively easy to calculate. But the more far-reaching consequences of the action, such as the loss of brand image among supermarkets and consumers, are not so easy to foresee.

It is precisely under these conditions that smaller manufacturing companies focus on vacuum testing systems from the INDEC series to minimise the risk of product recalls. It is also a way of signalling to the authorities and their trade customers that they meet the required standards and are available for lucrative new markets.

In food manufacturing, a good reputation is particularly important. The less often improperly sealed bottles and jars reach the consumer, the better. Only in this way can manufacturers protect the image of their brand, increase sales and secure their profits.

More and more small and medium-sized enterprises are realising that the best way to achieve these goals is with an INDEC series vacuum inspection system from KoCoS.

When you integrate an INDEC vacuum inspection system into your process, you can be confident that you are meeting current HACCP requirements and that your reputation and customers are reliably protected.

Multifunctional three-phase signal generator

With the EPOS 360 current and voltage source, KoCoS Messtechnik AG offers a signal generator that is recommended wherever maximum performance and the highest signal precision are required.

EPOS 360 has four voltage and three current signal sources. The signal curves are output via electronic power amplifiers. The parameters amplitude, phase angle and frequency can be varied over a wide range during the output.

Intelligent amplifier technology and synthetic signal generation make it possible to output any signal forms over a wide frequency range or even to play complex transient signals.

The TRANSIG monitor, included in the scope of delivery of the EPOS operating software, enables the graphical display and output of recordings that are available in SigDef format or in the standardized COMTRADE format. The corresponding signals are "played back" by EPOS as a transient sequence during tests.

In addition, the EPOS operating software contains a signal editor which enables the parameterization and calculation of any signal characteristics. These can be generated from a basic function, e.g. a sine and its superposition with one or more superposition functions, such as a DC component, exponential functions, harmonics, etc.

For special requirements, such as use in test benches, there is also a simple programming interface. This can be used in COM/ActiveX-supporting as well as in .NET environments.

For more information on EPOS 360, please visit the homepage. Ask our sales department for a quote.

LOTOS LT is a flexibly applicable standard measuring system and extremely cost efficient.
It is suitable for a wide range of applications in the automotive industry, in the field of medical technology, in the plastics and packaging industry, and also for fully automated testing of construction and insulation materials.

It has a height-adjustable operating touch screen and an integrated evaluation unit. Thanks to the small footprint, this standard module is extremely space-saving. The integrated evaluation unit ensures fast and fully automatic measurement evaluations. Inside, the LOTOS LC has various connection options to extend it with peripherals such as code readers. The stand-alone device is suitable for use in a production environment as well as in laboratory or measuring room.

Test parts can be measured at extremely high speed for 2D dimensional tolerances, as well as completely in 3D.

Example of measuring insulation materials:

Video of a measurement run:

Graphical measurement results:


Power Quality Analyzer with universal connectivity


The widespread use of power quality analyzers increases transparency in our power grids and reveals dangers as well as potential savings.

EPPE CX records and analyzes the power quality according to common standards and generates the required reports automatically. Network faults or disturbances are recorded via the transient fault recorder with high resolution.

In parallel to the tasks of power quality and fault recording, EPPE CX can be used via standardized interfaces and protocols, as a data source for third party applications like automation solutions. It also provides real-time visualization of measurement and process data.

Third party systems and automation solutions can access the EPPE CX measurement and process data via the standardized and widely used MODBUS TCP protocol, which is also part of the basic equipment of most PLC systems.

In addition, EPPE CX has been equipped with a modern and powerful webserver interface to display live measurements in numerical and graphical views on all common internet browsers on PCs, smartphones or tablets. Using this feature the live measurements can be monitored from all over the world without the need to install specific software applications.

The widget concept of the browser allows to arrange application specific views easily for each user.


The web server is available from device software version 2.06.0000.

This small video shows how to use the webserver:



For demonstration purposes, an EPPE CX has been permanently installed at the Headquarter of KoCoS in Korbach, Germany, which can be accessed from anywhere in the world.

Click the link to try it out now:


Username: Guest

Password: 2021

Saving of working time through simultaneous resistance determination at three measuring points

For switchgear in the medium-voltage and high-voltage level, the switchgear standard IEC 62271-1 requires a static resistance measurement of the main circuit in order to exclude an unacceptable heating of the current path.

Traditionally, the measurements are carried out one after the other and individually at each phase. The main circuit is supplied with 100 A direct current and the voltage drop is measured. If the measured value, i.e. the voltage drop is within the specified limits, the test is passed and the results can be recorded/stored. This measuring procedure is time-consuming as the three phases are tested one after the other.

To increase productivity and improve reliability, the measuring method for resistance and voltage drop measurement can be optimized with the PROMET R300 or R600.

The PROMET R300/R600 resistance measurement systems are equipped with three voltage measurement inputs, allowing parallel measurement at three measuring points, for example to measure the resistance of three main contacts statically.


In order to perform a simultaneous measurement of three main contacts, the test objects must be connected in series and provided with a test current connection. Since a four-wire measurement is carried out, it is important to ensure that the voltage connections are between the high current connections and that they are connected exactly at the points where the resistance is to be determined.

Connection example for a measurement on three test objects connected in series, e.g. three interrupter units.

In stand-alone mode, the three static resistance results with the measurement details (actual test current and voltage drop, measurement ranges etc.) can be stored in the measurement device.


The data stored in the device can be read out and managed with an easy-to-use PROMET software. The clearly displayed measurement results can also be output in a PDF test report or exported as CSV data.

The described simultaneous measuring method for the acquisition of three resistances thus saves working, changeover and measuring time!

As a further automation option, PROMET R300/R600 are equipped with interfaces for connection to the ACTAS 2.60 switchgear testing software. Resistance measurement can be conveniently integrated via the ACTAS test software. Even without an additional ACTAS test system, automated test sequences and a comprehensive analysis of the test results can be carried out without any problems.


The method is not only applicable in switchgear testing, but also in applications such as e.g. in the field of e-mobility, where several resistors have to be detected at the same time.

If you have further questions, please leave a comment or contact us directly.

Ensuring the highest product quality is a primary and indispensable goal, especially in food production. One of the standardized methods for preserving food without the addition of preservatives is vacuum packaging. By reliably lowering the oxygen partial pressure inside the container, the growth of spoilage germs is suppressed and thus the minimum shelf life of these foodstuffs is significantly extended. However, if the vacuum packaging is not absolutely flawless and has leaks, food can spoil long before the stated expiry date.

Vacuum inspection for bottles, jars and cans

The test procedure is based on determining the vacuum-induced deformation of the container closures as they pass through. The tightness of the containers is assessed by comparison with a previously Golden sample. Depending on the existing basic conditions, vacuum tests are possible from 50 µm deformation or from 150 mbar differential pressure in the headspace to the external pressure.


The INDEC systems work with an optical infrared sensor head. This means that metallic and non-metallic closures can be inspected equally. Starting with flow-rates of up to 600 pieces/min in the basic model, up to 1,200 pieces/min are achieved in the highest expansion stage for cap sizes of 30...110 mm diameter.

Convincing advantages through optical measuring method

The optical measuring method of the INDEC model series has a number of satisfying advantages compared to conventional methods. Due to the large working distance of the sensor head of more than 100 mm, the system is able to fully tolerate a wide range of deviations caused by dimensional deviations of the containers, horizontal track misalignment of the test samples and the unavoi-dable inaccuracies in the manual height adjustment of the sensor head.

Even vibrations of the conveyor belt and occasional drops of water on the caps do not affect the correct operation of the INDEC system, in contrast to other measuring methods.

INDEC the business insurance

Complaints, image damages, loss of customers and high costs are possible consequences of leaking vacuum packaging. The consequences can be serious, especially for the existence of small and medium-sized companies. The use of appropriate vacuum inspection systems should therefore be a matter of course wherever vacuum packaging is produced.

Unfortunately, the consistent use of effective inspection systems in companies that fill food is not a matter of course. During our on-site visits, we repeatedly see production facilities where no such inspection technology is used. The INDEC inspection devices are easy to integrate into existing plants and offer the possibility of updating existing measuring technology to a modern standard at low costs. As a complete installation, the turnkey INDEC test systems offer an "all-round carefree package" with which reliable quality assurance can be achieved quickly and easily.


How it all began

As early as the beginning of the 1990s, KoCoS was able to offer products and solutions in the field of disturbance recording and switchgear testing which were unique in terms of their precision, functionality and simplicity of handling and operation. The basis for numerous innovations was a completely new hardware platform in 32-bit multiprocessor technology. 


DMSS - Digital Measurement Simulation System

For the research, development and product testing of these new device generations, a special signal generator was needed, which was not available due to the special requirements. In order to ensure compliance with the specifications and the quality of the products, a special signal generator, the Digital Measurement Simulation System DMSS, was developed. With this system, it was possible to generate any signal waveforms synthetically by using software and to output them as high-precision analogue values via the appropriate hardware.

At that time, the first digital protection relays were already in use. Their functionality also made great demands on the devices needed for testing. For the most part, conventional test equipment was still in use for relay testing, in which transformers were used to generate the signals. However, these devices were not sufficient for testing digital protection relays.

With the Digital Measurement Simulation System DMSS, KoCoS had developed a signal generator that could also serve as the ideal basis for a new generation of relay test systems. What was still missing were components for measuring analogue and binary quantities as well as current and voltage amplifiers to provide the test values with the necessary amplitude and power.


Ideas, innovations and a new standard

The decision was quickly made to develop a relay testing system. For the measurement part, there were already sufficient solutions available from earlier developments. So "only" powerful and precise current and voltage amplifiers were needed.

But before the development could really get started, a precise specification for the new system had to be created. Of course, we first looked at what the market had to offer specifically for testing digital relays. There was not a lot. In fact, very few, and it was therefore not difficult to find a lot of ideas for the new system. Talks with users in the field of secondary technology, with whom we already had contact from the fault recorder application, were certainly helpful here.

The most important requirement, however, was defined by the management. On the one hand, the new relay testing system should be significantly more powerful and cheaper than the products available on the market. On the other hand, it should have unique selling points and advantages that offer the user a high benefit.

In addition, the new system should also define the future standard for professional testing systems. Not an easy undertaking, but it was completely fulfilled with the introduction of the ARTES 440 25 years ago. The many innovations and special features that the first ARTES 440 already had to offer will be discussed in more detail in future articles about the ARTES USPs.


Is it possible to perform a switching time measurement on a medium voltage system encapsulated in SF6 gas?

KoCoS offers a measuring method using the ACTAS switchgear test systems and external sensors which enables this type of system to be tested at a reasonable cost. As the system does not need to be isolated, the measurement procedure is even less time consuming than testing a non-gas-insulated medium-voltage switchgear using the conventional measurement procedures.

The VDS (Voltage Detection System) installed in the systems is used to measure the switching times. These are capacitive measuring points for voltage indicators or integrated capacitive voltage indicators according to VDE 0682-415 or IEC 61243-5. If no voltage transformers are installed, these measuring points are the only and safe way to establish a connection to the main contacts of the circuit breakers.

The capacitive measuring points can be connected directly to the analog measuring inputs of the ACTAS test system provided for this purpose without interposing additional measuring components. The capacitive measuring points are used to measure the three-phase sine wave of the voltages. If the circuit breaker is switched via the control room, the voltage drop is displayed on the ACTAS test system. However, in order to be able to determine a switching time, current clamps are used and attached to the open and close coils. External trigger signals that can be set in the test system can be used to initiate the recording of the measured values and the corresponding evaluation. External triggers can be set in ACTAS to any signals, regardless of whether they are individual binary or analog signals or signal groups.

The evaluation of the switching time in ACTAS is fully automatic; there is no need to set a cursor to manually evaluate the switching times and enter values manually.

What advantage do FIRST TRIP measurements offer?

As an online test, using the first-trip measurement method with ACTAS has some advantages over offline testing. From an economic point of view, the amount of time that can be saved is particularly relevant, as the disconnection and isolation of the breaker from other equipment is completely eliminated. In addition, there are also savings with regard to maintenance costs and resources if no defects are detected during the online measurement as this may make it unnecessary to carry out a test in offline mode.

  • No need to disconnect the circuit breaker
  • No need to disconnect control circuits
  • Savings in measurement time and resources
  • Breaker sticking/delay can be detected during the first switching operation
  • It may be possible to do without a complex offline test
  • Tests are possible under real conditions
  • No long downtimes for the components to be tested

Using ACTAS, first trip measurements can be performed on three phases. For connection to secondary current transformers, up to nine external analog sensors, such as non-contact DC or AC clamps, can be connected to the test system simultaneously and recorded. Up to three direct voltage measurement channels are available for voltage transformers. The measuring equipment and sensors are mounted while the breaker is in operation. Usually AC/DC current clamps are used which are mounted on the secondary side of the current transformers and on the operating coils. The operating times can be evaluated via the signals recorded accordingly and the characteristic of the coil current can give an indication of the status of the components of the switchgear.

Is it possible to perform FIRST TRIP measurements with ACTAS Px60?

As a component part of the power supply system, a circuit breaker functions primarily as a pure conductor within the network and the only requirement it initially has to fulfil is that its transfer resistance be as low as possible. And this situation often persists for years at a time. As long as no fault occurs, there is no need for the circuit breaker to operate. This is very much in the interests of the network operator, but it poses a considerable challenge to the technology of the breaker because as soon as a fault occurs, the breaker has to interrupt a high fault current within a few milliseconds in accordance with its specifications. This is not always achieved, one of the reasons for this often being inadequate maintenance, and it can be that during the course of the first switching operation the circuit breaker does not open within the time specified by the manufacturer.

One of the causes for this is friction which is created by deposits such as hardened grease or by environmental influences. The problem is usually solved by the first switching operation, as this loosens indurations and deposits. If this is not the case and the problem persists over a number of switching operations, it can lead to serious damage to the breaker itself and to the power network too, of course.

This makes it all the more important to service and test switchgear in accordance with the specified cycles. By measuring the operating times, conclusions can be drawn as to the state of the contact system, and the first trip is, of course, particularly significant. With conventional (offline) measuring methods, however, the breaker is disconnected and earthed before the test and this requires that an initial switching operation be carried out before the measuring equipment is connected.

This makes it impossible to draw conclusions about the behaviour of the breaker during the first trip. This is just one of the reasons why the demand for testing circuitbreakers “online“, i.e. without disconnecting them beforehand, is increasing worldwide. Another reason is that operating and maintenance budgets are constantly shrinking.

In addition, the demands placed on modern testing technology are increasing, using it flexibly and in a way that saves time is a must nowadays. KoCoS Messtechnik AG meets these requirements with its ACTAS Px60 switchgear test systems.

This makes it impossible to draw conclusions about the behaviour of the breaker during the first trip. This is just one of the reasons why the demand for testing circuitbreakers “online“, i.e. without disconnecting them beforehand, is increasing worldwide. Another reason is that operating and maintenance budgets are constantly shrinking.

In addition, the demands placed on modern testing technology are increasing, using it flexibly and in a way that saves time is a must nowadays. KoCoS Messtechnik AG meets these requirements with its ACTAS Px60 switchgear test systems.

GIS system with earthing on both sides, is it also possible to measure the switching times?

In outdoor switchgear systems (AIS), measurement with ground on both sides is generally not a major problem, simply because the typical ground resistance is much higher than the main contact resistance. KoCoS uses "Dynamic Timing" to combine the ACTAS switchgear test system with PROMET resistance meters.

The standards DIN VDE0105-100 and EN50110-1 clearly state that a GIS system must be measured with ground on both sides.

The problem, which is particularly relevant for GIS, is the very low ground resistance resulting from the encapsulation of the entire switchgear in a metal housing. It often can be that the ground and housing resistance is lower than the main contact resistance. This makes it difficult to carry out a condition assessment of the switchgear using standard measuring equipment.

For testing GIS systems grounded on both sides, the Dynamic Timing method cannot be used in the same manner as used with AIS testing grounded on both sides. It is not possible to measure the correct switching time of the circuit breaker integrated in the GIS.

The components installed in GIS like current transformers, cause measurement delays. Depending on the switching sequence, the result will contain correspondingly faster switching times when tripping or slower switching times when closing.

KoCoS uses the “GIS Timing” method to measure correct switching times. For this measuring method, the GIS must have at least one insulated ground lead to the outside. Again, PROMET resistance meters are used which generate current outputs of up to 600 A depending on the version. The resistance measuring devices are controlled by ACTAS. The resistance measuring devices are only used as current sources and not as actual measuring instruments.

In order to obtain measured values, in addition to the resistance meters and ACTAS, current sensors specifically developed for KoCoS are used. They are flexible Rogowski coils which can be attached to the insulated ground. The current curves measured during the switching operation on the insulated ground can be used to determine the switching times for opening and closing during the various switching sequences of the circuit-breaker.

This “GIS Timing” method has a great safety advantage and still offers the possibility of evaluating the GIS systems by means of measurement results and correspondingly recorded measurement signals.

Timing measurements of AIS and GIS switchgear, what are the differences?

GIS high-voltage switchgears are located at many nodes in our voltage network, such as three-phase or single-phase encapsulated switchgear panels. High-voltage switchgears consist of several components and can be designed differently depending on the required function. They contain components such as current transformers, disconnectors, ground switches, circuit breakers, etc. Compared to air insulated switchgear (AIS), they offer a number of advantages, including smaller space requirement, higher personnel safety, a longer service life, and higher reliability. Disadvantages compared to AIS are evident in terms of maintenance, as individual components are very difficult to access. Measurements, such as those of circuit-breaker operating times and resistance of the circuit-breaker interrupter units, are rather difficult to carry out, since the basic requirement is that in high-voltage installations, all the parts being worked on must be grounded.

In outdoor switchgear systems (AIS), measurement with ground on both sides is generally not a major problem, simply because the typical ground resistance is much higher than the main contact resistance. KoCoS uses "Dynamic Timing" to combine the ACTAS switchgear test system with PROMET resistance meters.

The standards DIN VDE0105-100 and EN50110-1 clearly state that a GIS system must be measured with ground on both sides. The problem, which is particularly relevant for GIS, is the very low ground resistance resulting from the encapsulation of the entire switchgear in a metal housing. It often can be that the ground and housing resistance is lower than the main contact resistance. This makes it difficult to carry out a condition assessment of the switchgear using standard measuring equipment.

Use of the Kelvin test probes KP 200 together with PROMET R300/R600

The KP 200 Kelvin test probes were developed for safe and easy resistance measurement at measuring points which are difficult to access. The test probe pair is equipped with spring-loaded high-current and voltage contacts for the determination of low-resistance according to the four-wire method for a test current of up to 200 A.


Can the test probes be used together with the PROMET R300 or R600 resistance meters?

The PROMET R300/R600 are designed with 13 mm high current sockets for the connection of 50 or 70 mm² high current cables. With the reducers 13/9 from 13 mm to 9 mm socket/plug diameter, it is possible to connect high-current cables with a smaller cross-section and 9 mm plugs or sockets to the PROMET R300/R600, such as the CS 205 cable set (2 x 5 m , 25 mm²).
With these cables it is now possible to use the KP 200 Kelvin test probes with the PROMET R300 or R600.


Furthermore, a measuring mode for the safe use of the KP 200 Kelvin test probes has been implemented in the stand-alone operation of the PROMET R300/R600 (from firmware version FWP 1.5).
According to the maximum load of the KP 200 Kelvin test probes, the current output in this mode is limited to 200 A.

If the measurement has started actively, the measuring device waits in this measuring mode for the test probes to be placed on the test object. A measurement is only carried out when the test probes are reliably and completely contacted (voltage and current contact). That is, the test current is output, the best measuring ranges are determined and the resistance value is measured. The measurement is carried out automatically with the shortest possible measurement time.

In order to simplify the use of the test probes on site, the current status of a measurement is also signaled by means of the LED status display and an acoustic signal.
The measurement result now remains on the display until the test probes are removed and the next measurement process is activated by placing the test probes. The resistance measurement results are displayed in a table and the results can be viewed before they can be saved.

With this sophisticated functionality, safe and automated operation of the KP 200 Kelvin test probes together with the PROMET R300/R600 resistance measuring devices is possible.

If you have further questions, please leave a comment or contact us directly.

Share of renewable energy is constantly increasing

In Germany, the share of renewable energies in 2019 was about 43% of gross electricity consumption. In total, about 242.5 billion kWh of electricity were generated from renewable energy sources. 

The aim is to increase the share to 65% by 2030.

The rapid expansion of renewable energy sources in the electricity sector worldwide is definitely the right way forward. However, it also generates undesirable side effects. For example, the structure of the electricity grid, which has grown over decades, is in many parts not designed for decentralized power generation. Many sections of the grid are already operated at the limits of their capacity. The more the decentralized expansion progresses, the more demanding and more difficult it becomes to monitor and ensure Power Quality .

Factors that accelerate the expansion of PQ measurements

The increased demand for PQ measuring points is a direct consequence of the expansion of renewable energy sources and the associated changes to the basic architecture of power supply networks.

There is a continuous and increasing change from a centralized generation model to a decentralized model in order to be able to integrate more and more renewable energy sources - often in smaller power categories and in highly distributed design.

This new model fundamentally changes the characteristics and the electrical signatures flowing in the system.  A change that creates an increasing and urgent need for accurate measurements of power quality at more and more locations within the distribution network. These measurements are not only used to record and monitor quality parameters, but also to detect undesired interactions between network components, which often occur only under certain operating conditions and can lead to shutdowns, unstable operating conditions or a reduction in performance.  

The fundamental changes in our power generation and distribution systems make it necessary to take the monitoring of power quality and the complete recording of all network processes even more seriously in the future.



Our measurement systems of the EPPE and SHERLOG product line offer a reliable and robust platform and can be used on all voltage levels.

Lightweight and compact,

or bigger and heavier than expected?

At first glance, it seems that the ARTES RC3 is the little brother of the ARTES 460 because of the smaller number of inputs and outputs, just extremely robustly packed. It would therefore be expected that the RC3 would also be more compact and lighter than the ARTES 460. According to the specification, however, this is not so.

During the development of the ARTES RC3, high demands were placed on its robustness, reliability and durability. The basis for these requirements was already given with the 4th ARTES hardware generation. This has already proven itself in the ARTES 460/600 and is considered one of the most robust, if not the most robust hardware platform of all relay test systems on the market.

For the integration of the components into the RC3, a specially stable mechanical construction has also been developed inside a hard-shell case. Due to the construction and the robust and resistant hard-shell case, even hard shocks and vibrations have little effect on the RC3.

The dimensions and weight are higher for the first time.  In practice, however, this looks quite different. A relay test system is rarely used in the laboratory or in the workshop. Rather it is transported to the application site. And especially during the transportation the size and the weight are very important. Later during work the test system is moved rather less.

For safe transport, ARTES 460 is equipped with a robust transport box specially designed for this purpose. Inside the box there is a hard foam insert which fits the device and the cable set perfectly and which determines the external dimensions of the box.

Due to its construction in a robust hard-shell case, no additional transport box is required for the ARTES RC3. In comparison, it is a very compact and lightweight system which is very easy to handle in practice. This also makes the ARTES RC3 ideal for demanding outdoor use in rough environmental conditions. Larger and heavier than expected? Rather not.

Useful addition to the ARTES product line

With the ARTES 460 and ARTES 600, two very capable test systems are offered which provide almost all functions for protective relay testing. Where does the ARTES RC3 come in here and how does it differ from the other systems? 

ARTES RC3 has some features and advantages that are particularly useful for certain applications and target groups.


Renewable energy generation plants, especially wind turbines and solar parks, have become more and more important worldwide in recent years. In these plants there are special relays, such as the Q-V protection, which have to be checked regularly.

Energy suppliers and grid operators are often not in a position to comply with the tests due to the large number of installations and are often not the operators of these plants. The testing of protective relays is therefore more and more carried out by service companies.


The aim of developing the ARTES RC3 was to take into account the special requirements of these service providers or service companies. The new RC3 is also suitable for almost all other protection tests in the field of electrical power supply.

There are certainly some limitations due to the number of current amplifiers when testing differential protection relays. However, tests of frequency, voltage, overcurrent, distance protection and many other protection relays can be carried out just as well and efficiently with the ARTES RC3. In addition to the local operation, the new ARTES 5 software with all its special functions is also available for the RC3.


But what are the criteria that are especially important to service companies? Due to the number of test systems required, price is certainly a very important criterion for many customers. What they are looking for is a cost-effective solution that provides all the necessary functions but does not contain additional, expensive features that are not required for the specific application.

Another important point is the robustness of the device. The environment in which the tests are carried out often does not meet that of many conventional plants. Harsh environmental conditions are often encountered in regenerative energy generation plants. The high demands on robustness, reliability and durability were particularly taken into account in the development of the ARTES RC3. The RC3 is very well protected due to its design in an extremely robust hard-shell case.


And last but not least, the possibility of being able to carry out tests completely without a PC is often very useful for tests in regenerative energy generation plants. Even the test results of the RC3 can be read out via smartphone without a PC using the new ARTES app and clearly displayed in a test report. This report can also be sent by e-mail as a PDF file directly on site. 



The ARTES RC3 should therefore not be seen primarily as a replacement for the ARTES 460 or ARTES 600. Rather, it complements the product line in a meaningful way and offers exactly what a large customer base specifically needs.