The SPC25 is intended for use in TNC systems (1+0 or 3+0). For TNS and TT systems (1+1 or 3+1) the SPC25 is equipped with high energy gas discharge tube for equipotential bonding between N and PE.
The main use of SPC25 arrester is in structures of LPL I according to EN 62305, e.g. hospitals, banks, mobile operator stations, water-stations, power plants, airport buildings for air traffic control.
To be installed in the main switchboard.
Function of remote monitor terminals
When the SPC25 DS is operating correctly, the terminations 1-2 are connected to normally closed contacts, 2-3 are normally open. If the internal varistor component is damaged as a result of thermal overloading, terminations 1-2 will then be open and 2-3 closed.