A reason, is the water pump: choose power don't match, a small cart, electric thoughts run overload for a long time to make electricity thought high temperature through; Startup too frequently, quota of short-time or intermittent duty of electric idea work continuously. Start times should be limited, accurately choose thermal protection, according to electric idea is used in calibration of the norm.

Second, the idea itself is electricity: connection error, delta shaped misconnection into Y, by raising the temperature of the electric thoughts quickly; Stator winding turn-to-turn short circuit or local interphase short circuit, grounding, light when electricity thought local overheating, insulation when severe burn out; Squirrel cage rotor broken bar or flaws, electrical thoughts run 1 to 2 hours, core temperature rising rapidly; Drafty system failure occurs, should check whether the fan is damaged, the direction of rotation is accurate, drafty channel blockage; Bearing wear, swept rotor eccentricity chamber makes the stator iron core facies to wipe a clang, core temperature rising rapidly, serious when electricity thought smoking, even coil burned.

Three, is the power of reason: high or low voltage, under certain load, if the voltage fluctuation range should be + 10% to 5% of the rated value beyond thought can cause electric overheating; Three-phase voltage differences, according to the error and unbalanced three-phase electric voltage degree is more than 5%, will lead winding overheating; Lack of phase operation, experience suggests that electrofarming idea was burned down by more than 85% because of lack of phase operation, dealing with electrical installation phase protection device.

Four, is the work environment reasons: electrical thought winding be affected with damp be affected with damp or dust, oil and other adhesion on the winding, results in the decrease of insulation. Should measure the insulation resistance of electrical thoughts and cleaning, drying, processing; Environment temperature through high. When ambient temperature more than 35 ℃, inlet air temperature is high, can make the temperature of electric thoughts through the high, should be thought to improve their working environment. Such as scaffolding shade, etc.