Analysis with mobile data acquisition

Electric locomotives are equipped with surge arresters that work like lightning conductors and protect the instruments from damage caused by sudden overvoltage. But what happens if these surge arresters do not work reliably for unexplained reasons? Mobile data acquisition with data loggers from Althen enables Meinke Energy to make a meaningful analysis when faults occur. At an industrial company with its own railway traffic, retrofitted surge arresters frequently failed during operation. One assumption about the cause of the failure was that the arresters could not withstand the high thermal development during operation, i.e. they overheated colloquially. In order to be able to determine this with certainty, the framework data had to be reliably recorded during operation. If a fault occurs during operation, the cause must usually also be searched for during operation.

The measurement task

Meinke Energy needed compact and at the same time powerful devices for data acquisition on site, which record all the necessary information for a later thorough analysis. The Graphtec data loggers from Althen have proven themselves in use here.The measuring task was to check the behaviour of the voltage. For this purpose, the traction voltage on the overhead lines is fed down to a maximum of 1,100 V in the locomotive using converters. The converters are connected to the surge arresters and were to be measured during operation. A tour of the locomotive lasts three to four hours, so it is quite possible to start the data recording at the beginning of the shift and let it "run". Space is limited in an electric locomotive, and due to its movement, any solution for data acquisition must not only be particularly compact and portable, but also reliably transmit and store the data. At the same time, it is necessary to record many different data, which later provide the basis for detailed evaluation. Data loggers from the manufacturer Graphtec in Althen's product range meet these requirements. While the electric locomotive completes its tours, the data logger records the relevant data for troubleshooting and makes it available for evaluation. The compact devices from Althen are ideally suited for this purpose.

Reliable recording

The requirement for the measurement task was complex, not only because of the sensitive situation in case the locomotive has visible problems in the public rail network. The framework data also required the use of two devices, because on the one hand the high dielectric strength had to be given, which the GL 980 offers. On the other hand, there are many different parameters during operation with start and stop signals, speed and the resulting temperatures, for the recording of which the GL 840 is ideally suited. The measurements were carried out on the locomotive for almost a week.

Data is in demand everywhere

Data loggers are used in quality assurance in production, but also in research facilities or for targeted troubleshooting during maintenance. In principle, they record all data that a sensor can measure, such as voltage, vibration, strain, temperature, humidity or flow.

Althen recommends the most suitable data logger for the respective application. For the troubleshooting that Meinke Energy carried out in the E-Lok, the GL 840 M and GL 980 models were selected, each as a kit version in a measuring case and with battery operation for mobile use. In both cases, Meinke uses the SD memory card to record the data. Alternatively, Althen also offers the data loggers with a USB memory. For remote monitoring, there is the option of sending the data by email or transferring it to a cloud using an ftp client.