We encounter standardised connectors everywhere in day-to-day life: the micro USB on the cell phone, the RJ45 on the PC, the charging plug for electric cars – whereby interoperability is increasingly essential. The purely visual appearance of a connector can be deceptive. Not everything that can be plugged in together works reliably or safely. A household’s Schuko socket can transmit a maximum of 16A, meaning you can connect a fan heater up to 3.6kW. The connector/socket then often heats up, and plastic parts start to fry. But everything meets the specifications, right?
As developers of safe high-end connectors, HARTING engineers would take this contact pin and optimise it, together with its counterpart, the socket, by employing special contact surfaces, materials and sophisticated geometries, so that currents up to 40A can be transmitted. Here, it’s important that both parts - the pin and socket - are optimised in unison. While manufacturers of industrial-grade connectors do this, however, everyone does things their own way, harnessing their own know-how in the process. The result is that it’s not safe to insert manufacturer A’s contact pin into manufacturer B's socket, and the outcome could quickly resemble the scene described above. Standardisation, on the other hand, is intended to make this type of mixed use safe. But how? The answer: not through standardisation alone, at least. One common method here is to reduce the power specifications while standardising the basic properties of the contacts. Hence, the coordinated, high-performance system for 40A. However, at times this seems to be inadequate, since we’re all familiar with pictures like the one above. On the other hand, engineers should come up with something more than just downgrading. A contact system that offers high performance and that is suitable for mixed mating is called for. This requires extensive, detailed specifications, and the parties involved in the standardisation process need to agree on them. The crux: someone has to be the first to disclose their thoughts on this within the standardisation committee, which is understandably difficult.
Once this has been achieved, the manufacturers’ different manufacturing processes must be taken into account, e.g. by designing tolerances more generously than one would when optimising the contact pair. The performance of a standardised contact pair for mixed mating is always inferior to that of a non-standardised pair whose two sides have been coordinated down to the last detail. The additional technical development possibilities of such an extensively detailed system also lag behind those of a proprietary one.