A single phasing preventer is utilized to shield the acceptance engine from a solitary staging issue. Single staging is a perilous shortcoming to the electrical engine and Which harms the engine stator twisting quickly. For the most part, single staging is only an engine runs at one of the inventory is isolated because of the open circuit or ill-advised contact in a switch or other electrical gear disappointment. Regularly, the engine runs with the three-stage supply and which brings balance presently in each stage winding. Dissect one of the wires has blown. However, the machine still in a pivoting position which attempts to turn at a similar speed. At that equivalent time, the need stage current will be moved to the staying live stages. Subsequently, explicit current in different stages increments up to multiple times its typical worth in a flash. This is known as a solitary staging shortcoming.