... ,power substation automation,smart building andswitchgears,ect.with simple installation,convenient maintenance and small quantity ... and negative) (3CTs is required)4.With 2 loops of switch input ,adopt dry node point ... resistance signal input mode.5.With 2 loops photo couple relay switch output,and alarm ... ,IP,IN,20pieces SOE event record,2 loops energy pulse output,1 loop RS485 interfaceOrder ...