Technical details System pro M compact®

Systempro M compact ®Technical detailsOVR Surge Protective DevicesSPDsThe fi rst surge arrester diverts mostof the current to the ground and theremaining surge current is divertedto the ground by the second surgearrester.The value of this remaining surgecurrent gets lower as the distancebetween both surge arresters getslonger. The lower is the currentgoing through the last surge arrester,the lower is the voltage protectionlevel applied to the downstreamequipment.Principle of coordination for Surge Protective DevicesThe fi rst surge arrester does not provide effective protection for the whole installation byitself.Certain electrical phenomena can double the protection’s residual voltage if cable lengthsexceed 10m.Surge arresters must be coordinated when they are installed refer to the tables below.Coordination required if:The first surge arrester does not reach the protection voltage (U p) by itself.The fi rst surge arrester is more than 10m away from the equipment to be protected.Coordination between Type 1 and Type 2 surge arresterType 125 kA10/350➤L > 10 m(10 m minimum between the two devices)➤Type 240 kA8/20Coordination between Type 1+2 and Type 2 surge arresterType 1+225 kA10/350➤L > 10 m(10 m minimum between the two devices)➤Type 240 kA8/2011Coordination between Type 2 surge arrestersType 270 kA8/20➤L > 1 m(1 m minimum between the two devices)➤Type 240 kA8/2011/82 ABB