1.Mechanical failure of the pump itself. Impeller and pump shaft fastening nut loose or pump shaft deformation and bending, resulting in multi impeller, direct friction with the pump body, or bearing damage, it is possible to reduce the pump speed.
2.Human factors. Some users because of original motor damage, may be accompanied by another motor, resulting in a flow of small, low head or even the consequences of no water.
3.The engine maintenance. Motor due to the winding burn, and loss of magnetism, maintenance of the winding turns, wire diameter, wiring method changes, or the failure of the maintenance of the fault is not completely eliminated factors will make the pump speed change.
