400V cut-off is one important node at Low voltage power distribution because it works as a transition between power consumers and the main power grid. A cut-off switch, or normally known as breaker or automatic switch, is generally installed at this point. The cut-off switch mainly works to protect the safety of the main power grid and the power consumer instead of disconnecting the load. Its working principles are as follows: when a power consumer runs into trouble, the cut-off switch will become released automatically so that the power grid on the side of the consumer is physically isolated from the main power grid, hence avoiding massive spreading of the trouble towards the main power grid and failure of the latter. Moreover, the cut-off switch will be released automatically upon failure of the main power grid so that the power consumer is isolated therefrom. It can also guarantee stable operation of the main power grid when it is reenergized because it is not loaded. It also reduces the impacts on the power consumer and hence protects the safety of both the main power grid and the power consumer. Considering the importance of 400V cut-off node, it is required to install a cut-off switch with automatic release at this node according to relevant electric operating regulations. But there is one problem in practice, i.e. the release can’t be automatically reengaged after it is activated. As such, massive and difficult manual operations are required for this purpose. To make it convenient, automatic release is normally cancelled for most cut-off switches in practice and it creates considerable safety hazards. Our 400V cut-off switch intelligent controller is designed and developed to solve this problem.

Our 400V cut-off switch intelligent controller is furnished with an intelligent test circuit and a remote GPRS communication and SMS communication module. When the cut-off switch runs into troubles, the intelligent controller can immediately send a trouble alarm message, indicating the type of trouble and the recommended solution, to the collective control station and the cell phone of the line manager. Such recommended solutions may include requesting the manager to conduct a field inspection or disabling some features for safety’s sake. Meanwhile, the intelligent controller is also capable of real-time trouble monitoring so that it can notify the collective control station and the line manager immediately after trouble shooting. In addition, this controller can also enable the user’s remote manual closing of the mains switch and provide feedbacks to the collective control station and the line manager upon success of energization.