Abb ground zs4 screw clamp terminal block abb 1snk505150r0000 p a snap in rail connection for rapid installation and removal for 4 mm sup2 10 awg up to 16 mm sup2 4 awg ground terminal blocks p p simply snap it on the din3 th35 rail and it is connected to the rail strict qualification tests in addition to those required in iec standard 60947 2 have been performed to guarantee the reliability of the snap in rail connection in mechanical endurance and lifetime performance p p the s