The Plabutsch Tunnel, Graz, Austria: The 10 km long Plabutsch Tunnel, which runs straight through the middle of Graz as part of the Austrian A9 freeway, connects the Balkan States with Central Europe. The safety of the road-users was the priority in constructing the tunnel.

Almost 1 0,000 intercepted measuring points and messages are led over 300,000 terminal points and 750 km of cable. This electrical equipment proved to be very prone to interferences. A large number of failures occurred, including the partial destruction of different components due to surge voltages. Only when the comprehensive surge voltage protection concept TRABTECH from PHOENIX CONTACT was implemented did the availability of the equipment increase significantly.
In this case, pluggable and testable COMTR,AB surge arresters were used to protect the MCR cables. These surge arresters only require approx. 5 mm per channel for coarse and fine protection.