The NSX mounting plate system for busbar simplifies the installation of 4 poles NSX 400-630 circuit breaker. Power distribution is performed by a busbar. The mounting plate is fitted directly on the busbar, by snap-on-mounting. thus implementing mechanical and electrical connection. The busbar interaxis is 60 mm. Depending on the cross section of the bars, the busbar associated to terminals can withstand a maximum current of 630A. This system offers numerous benefits as space saving in cabinets and easy connection. This system also offer fast, safe and reliable electrical and mechanical connection. This system also offer IP20 protection by using busbars and end covers. This system also offer easier maintenance and equipment flexibility and modularity.