In a DC system, the correct earthing connection is the base of each safety procedure during maintenance or equipment replacement operations.
The former solution provided the use of an earthing hook between contact line and rail but in many cases, this solution is not acceptable due to the limitation to the transit of assistance and/or maintenance means.
The earthing switches solve this problem with certified short time current withstand with main contacts visibility and with the possibility to add safe mechanical interlocks. COET’s solution gives the opportunity to have safer devices with a making capacity as large as the maximum short circuit current of the system.
MAT line, whose making capacity reaches up to 100kA, is suitable to be used in any Power Supply System for Tram, Trolleybus, Train and Metro substations and is in compliance with the most severe International Standards.

Coming to Tunnel safety (European directive 2001/16/EC) where, besides earthing it is also needed to short-circuit the positive pole to the negative, COET designed on purpose a special double function disconnector with making capacity of 50kA and 100kA.