Rutronik News

Robust Connections


Smart manufacturing ("Industry 4.0") is based, like the Internet of Things, on connectivity – and that means contacts. The connectors needed for the purpose must be of sufficient robustness for industrial use. So Industry 4.0 is not just a driver of growth, but also of technological progress, delivering a multitude of innovations. They are also benefiting other sectors.

Almost all applications in machinery and plant manufacture and automation are subject to extreme conditions such as damp, dust, oil, chemicals, high temperatures, and vibration. At the same time, safeguarding plant safety is a must. Many manufacturers have already responded to those demands, developing connectors conforming to different standards which are certified to EN 60529 and offer IP67 or IP 68 protection. This is especially so in relation to the M8 and M12 connector types most frequently used in industrial applications, but also to modular jacks and USB. 

It should be noted here that the protection class applies only to the connected condition. As soon as one end of the connection is open, the protection is generally no longer assured.

Molex offers a particularly extensive portfolio of robust solutions: The Sealed Connectors series comprises standard and custom sealed connectors of different protection classes. [Are there models here that should be highlighted?] à Waterproof micro-USB from Molex - Series 105443

In-cabinet automation components mostly feature connectors for single-wire connection. That is because they enable very flexible connections of sensors, actuators and the power supply. In power electronics, developers are increasingly turning to circuit board connectors in place the previously more common clamped solutions. They permit more compact and flexible equipment designs, as well as delivering high current carrying capacity.

Industrial standard connectors such as RJ45 and round plug connectors are becoming ever more widespread for data connections, because field bus systems are increasingly being replaced by Industrial Ethernet. Fiber-optic connectors permit fast, interference-free transfer of large data volumes.



Automotive components have to be meet the highest safety demands, and the development of more robust models is very much in keeping with those demands. Other core requirements in that sector are space and weight saving. Consequently, some manufacturers are already offering systems with more than 300 contacts. High-performance alloys such as CuNiSi additionally improve their current carrying capacity, so enabling smaller solutions, while materials like aluminum and copper alloys save on weight.

As one example, JAE has developed the MX19 series specially for the automotive sector. The small wire-to-wire connectors, certified as waterproof to JIS D0203 S1, connect with just a click. They can withstand temperatures between -40 and 105°C, as well as the typical vibrations that occur in vehicles. Thanks to its grommet with backward sealing, the MX19 series provides optimized layout of the harness assembly, and the terminals fit better in the enclosure. The seal protects against damage, cable flapping and water incursion. The terminals feature a double-plate spring mechanism with a long carrier length for low insertion forces and pressure dispersion. Rated up to 5A, and for cables between 20 and 22 AWG, 2- and 4-pin variants are available.



Hybrid and electric vehicles have introduced new voltage and current classes. That also means significantly higher temperatures and vibration levels. Moreover, there is a risk with electric powered vehicles especially that environmental influences such as water, dust, dirt, oil, chemicals or electromagnetic fields might impair performance. Consequently, the demands on the design, base materials and contact surfaces of the connectors are more stringent. No standard has yet become established; the OEMs are mainly applying custom solutions. The situation with regard to connectors for the charger unit is different: They have established standards: Type 1 (mainly in America and Japan), Type 2 (Europe) and GB/T (China).

Amphenol has developed its PowerLokTM high-voltage, high-current connection system specially to meet the requirements of chargers and cable assembly for hybrid and electric vehicles. It is based on RADSOK® (RADial SOcKet) contact technology, which ensures less voltage drop and temperature rise, and enlarges the surface area thanks to its radial design. The PowerLok connectors are rated for 750A and 1000V, and feature HVIL (High Voltage InterLock) current protection. The second automatic interlock ensures that the terminals are optimally positioned, and provides sufficient holding force even for rough environments. Its various groove options ensure secure connections, avoiding the risk of damage due to faulty connection. It makes the typical clicking noise that is very popular in the automotive industry. The simple connection guarantees maximum protection for the user. If the lock is opened, the high currents are immediately cut. The enclosure conforms to UL94-V-0, RTI130,CTI2 as a minimum, and is able to withstand temperatures of -40 to 125°C. The 360° metal sheath ensures complete shielding of the connector for IP6K9K when plugged and IP2X when unplugged (to DIN 40 050, 9).

Amphenol also offers a connector series for energy storage devices, specially designed for high-current connections in the battery module and in the battery management system (BMS) itself: The low-cost RADLOK family comprises a series of plug designs, and can be used both inside the battery as a cell-to-cell connection and externally as a battery-to-battery or array-to-power store connection. It features low insertion and removal forces, and a large number of plugging cycles thanks to its integrated locking and unlocking mechanism. Its maximum current capacity is 750A, with maximum DC voltage of 1000V; its temperature range is from -40 to 125°C.


Rail connections

In the rail sector, demand for connectors is rising due to the increased deployment of Ethernet networks, such as for cameras and displays, and due to the trend toward modular train design. The subsystems have to be easily connectible, so as to route power, data and signals through all the on-board units.

For outdoor use, the connectors not only have to withstand vibration and shock impact, but also all kinds of weather conditions. These applications demand models with IP68 or IP69K protection and mechanical interlocks. In the train's interior, lesser protection is sufficient, though electromagnetic fields play a greater role. Shielded connectors are available for this.

In addition, all connectors must conform to railway standards. They differ from country to country. They normally include high resistance to hydraulic fluid, aggressive cleaning agents and similar substances.



The connector requirements for LED lighting solutions are very difficult to specify clearly, as they vary according to the location of use and application. But the rule is: the more robust the connection solution, the broader will be its range of applications - like the SSL-1 series from Amphenol. With shock and vibration proofing to EN 61373, it is suitable for indoor and outdoor LED applications as well as for the transportation market. It has eliminated soldering, entailing the risk of low-quality solder joints, and so delivers shorter SMT production times and reduced costs. It takes up less space on the PCB, making more room for greater LED density. This avoids shadowing. The SSL-1 series comprises 2-, 4- and 6-pin board-to-board, wire-to-board and wire-to-wire connectors.


Medical technology

Medical technology applications must first and foremost conform to the industry standards and licensing requirements governing shielding, leak-tightness, autoclavability, and touch protection. Other frequent stipulations are high contact security and large numbers of plugging cycles, as well as protection against disinfectants and aggressive cleaning solutions.

Connection systems which meet high demands usually entail complex production processes. Moreover, their development costs are often not yet amortized through mass production. That makes them relatively expensive, so they are not suitable for cost-sensitive applications, or applications in which the protection offered is not actually necessary. For all other applications, however, they offer many benefits - or are even a must. 


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