EN 50155 standard regulates all the details required to test the functionality of the electronics on a train. The aim of the tests is to achieve a functional capability that lasts 24 hours a day for 20 years. This covers approximately 175,000 hours. All requirements are defined that must be met under all conceivable environmental conditions. This includes shock, vibration, fog, salt and the like. In addition, the EN 50155 standard specifies how to deal with fluctuations in supply voltages and their transients.
Whether a device is fully functional can be clearly demonstrated using various test criteria. These are:
According to EN 50155, the ambient temperature for the tests must be between - 40 and + 85 degrees Celsius. All components and printed circuit boards are to be tested under these conditions. They are required to withstand condensation that occurs in connection with temperature rises of values below zero.
When testing the humidity, a relative humidity of 75% must be given. This is an average value followed by 30 consecutive days of 95% relative humidity each. Watertight housings and assemblies with protective coating are subjected to these conditions.
Environmental pollution is tested in conductive dust, in oil mist or in sulfur dioxide. An IP-rated enclosure can avoid the negative consequences that can occur due to environmental effects.
In order to test the cooling, forced ventilation should be avoided according to EN 50155. Otherwise, increased maintenance work would be required.
During EMC testing, possible electromagnetic interference must be tested. In this context, transient and burst resistance must be demonstrated. In addition, the radiation resistance against radio transmitters and the radiation of radio waves is tested.
According to EN 50155, there are various test methods and limit values for testing shock and vibration. The aim here is to clarify how the existing technology reacts in an environment that is exposed to high vibrations.
In addition, the input voltage, input voltage ripple, and input magnitude surges can be tested in the trajectory domain.