Siviko ACT 150 is an innovative automated cable tester that offers a reliable and convenient automated solution for cable manufacturers and distributors that want to ensure the quality of their products by running in-house electric tests for active resistance, withstand voltage in a fast, convenient, safe and non-destructive manner. The cable tested in an automated and digitalized laboratory – it ensures through hardware and software the safety of the operator, it organises the tests in compliance with the relevant standards for low-voltage cables and decreases the amount of manual work. It also has an automated procedure for the location of short-circuits and line breaks. The results are recorded in a database. All this enables improved quality control and shorter test times, without destructive impact on the cables. The output power of 150 kVA allows for testing of low-voltage cables with up to 50 wires and length up to 20 km. The cable tested could test simultaneously 4 objects (e.g. different cable lengths). Siviko 150 has several safety layers: independent hardware and software safety chains, safety fence with auto-lock units, automatic grounding unit – Siviko AGS, indicators and emergency buttons.

Why perform electric tests?

The electric tests for resistance and voltage for the whole length of the cable are basic indicators for the material and manufacturing quality of the cable core and its insulation layers. Higher resistance shows that the material of the core is of poor quality or cross-section out of specification, which will result in increased power losses. The high voltage withstand test shows the quality of the insulation. If a break in the insulation occurs during the high voltage test then the insulation has a manufacturing defect or is made of poor quality materials or it is simply insufficient. Such low-quality insulation will inevitably result in short-circuit that might cause a fire, damage the electrical equipment or cause fatal accidents. Therefore it is understandable, why many customers require a test report that ensures the quality of their purchase.

Challenges

The standards state that the electrical tests require the cable has to comply with several requirements before a conducting a test. It has to be in the dry state and at ambient temperature when a voltage is applied of the magnitude given in the relevant cable standard, supplied from an A.C. source, between each conductor and all the other conductors and, if any, the metallic layer connected to the earth. Then the voltage has to be gradually increased and maintained at the full value for the duration given in the relevant cable standard.

If one is to manually perform such tests, he is to face many problems and inconveniences. First of all, he has to have A.C. power source that could reach the desired high voltage of up to 4000 V. Second, he should have appropriate calibrated measurement equipment to measure the resistance and voltage and he has to be able to connect them properly and to run the appropriate tests. Third, he has to manually switch between each group of conductors, and they could be many of them. This is not only time-consuming but could also lead to accidents due to the high voltage applied. Last, but not least the operator has manually to write down the test results in his test report and then to keep the records organized and available.

Automation

Siviko ACT 150 takes care of all those problems and has some additional functionalities that facilitate the work of the operator. The core automation of the cable tester is realised with hardware and software by WAGO Kontakttechnik GmbH & Co.

At the core of the automation systems is the programmable logic controller (PLC) Wago PFC200 750-8202. It is a new generation and has many important tasks to perform. The resistance tests are performed by an industrial ohmmeter that is controlled by the PLC. The communication is done through RS-485 (MODBUS RTU), and the date is refreshed in less than 20 ms. The acquired data for resistance is temperature corrected through a Wago 750-461 module. The accuracy of the resistance measurement is very important as it is also used for the localization of short circuits in the tested object.

The voltage test is done with two PQA modules Wago 750-495. With them, one can measure current, voltage, power factor and etc. With those parameters, the PLC controls the applied voltage, compensates the capacitive load of the test objects, it could locate line breaks and it could calculate the consumed energy.

The PLC has 96 input/output that controls and operates all automated processes. All of them get data from sensors and control different actuators that are used during the test procedure.

The human-machine interface (HMI) is entirely digitalized. The only buttons in the system are the four emergency buttons. We have used the modern paradigm for high-performance HMI. The process is controlled through two touch sensors. For the measurement for resistance is used a Wago e!DYSPLAY 7300T, while the overall process is tracked and recorded by an industrial touch computer. The process data is recorded by the PLC in a database located in the industrial computer.  We have used one of the most popular databases – MySQL. The memory loss risk has been mitigated through a UPS Wago 787-870. The system has been programmed with the help of an e!COCKPIT 1.3. that is very flexible and intuitive integrated environment for development, which allows for programming and tracing of parallel processes, the creation of HTML5 visualization and holds numerous libraries. As a result, the system has been programmed with hybrid-built software that consists of Siviko Smart OS that takes care of the databases and the system events and Wago WebVisu that shows the process in real-time. This concept allows the data to be accessed remotely by the managerial personnel without interfering with the ongoing process and it also allows for easy integration with higher-level systems such as SCADA, MES and ERP.