Phoenix Contact 3213963 For a secure and fast push-in connection, supports should be installed at the start and end of each terminal strip as well as every 20cm on longer strips. The neutral busbar is secured using this method. The circuit specifications include a nominal voltage of 250V and a nominal current of 24A. A 2.5mm2 rated cross-section is used, with the actual cross-sectional area ranging from 0.14 to 4mm2. This push-in connection is classified as NS35/7.5 or NS35/15, with the entire assembly mounted on blue-colored supports.