Surge protection for measuring and control technology
Measuring and control technology conductors are considerably more sensitive to surge voltages than those of the power supply systems. As the central nervous systems of industrial plants, they require a high degree of availability. Arresters with combined protective circuits are therefore used for their protection. These are installed directly before the signal inputs to be protected. This avoids the risk of surge voltage coupling along the conductor route between arrester and interface.
Typical areas of application for analog two.conductor measurement are flow measurement and level measurement. In the field of voltage signals, potentiometer positions or slide settings are queried. Temperature measurements or level measurements in tanks are common in the Ex(i) area. The connection system and the required space must fit the installation environment. This is why the surge arresters for MCR technology are available for a variety of connection systems.
The choice of surge arrester is based on four different factors:
- Signal processing, such as two, three or four-conductor system
- The maximum signal voltage
- Surge withstand capability and
- Transmission frequency.
The site in which the surge arresters are used must also be taken into account. Protection of intrinsically safe circuits, for example, makes special requirements.
The pluggable arresters from the PLUGTRAB PT or COMTRAB modular range of products are particularly convenient. In the case of servicing or maintenance, it is not necessary to tamper with the installation. The plugs can quickly be removed from the base element and checked with the CHECKMASTER tester.
