I/O connectors with integrated surge protection
Electrical control cabinet designers and builders normally integrate separate DIN-rail mounted surge arrester devices to offer in-line protection to the most sensitive circuits. These typically consist of multiple I/O sensors and switches which are generally installed in the control cabinet, each taking up around 6-12 mm of DIN rail mounting space. More significantly, they require time and wiring effort, and involve noteworthy extra cost.
To address this challenge, Harting has developed an interesting new approach that saves important internal control cabinet space and enables a potentially more cost-efficient higher density cabinet design. This solution moves the in-line surge protection circuitry out of the cabinet and integrates it directly into the I/O interlinked connector. This is achieved through a new surge-protection module that has been added to the Han-Modular range of connector inserts. As a result, potential overvoltage transients are effectively stopped at the cabinet wall.
The Harting Han Surge Protection module is available in two different versions to allow protection for both digital and analogue binary I/O sensor circuits: a “common mode” E-Type asymmetrical voltage type, for binary signals with common ground-like digital circuits and a “differential mode” symmetrical voltage version, for closed signals like analogue circuits. Both versions have integrated protective circuit designs, as developed by surge protection specialist partner Dehn + Söhne to ensure total fail-safe operation, independent of the cause of failure within the surge protection module.
The transients, which can interrupt signal circuits and destroy electronic devices, are discharged to ground within the connector via a spring element that makes conductive contact with the Han-Modular hinged frame, which holds the modules in position. For the correct discharging of the signals, it is essential that the frame is connected with the ground.
Typical applications for the “common mode” type include protecting digital I/O sensors such as inductive or ultrasonic proximity switches, often used in general factory automation production environments. The “differential mode” type is often used in industrial manufacturing sectors including chemical, pharmaceutical and food & beverage processing, as well as wind energy.
Harting – www.harting.co.uk