Various fault and high-voltage electrical maintenance status of high-voltage motors recurring analysis service

Various fault and high-voltage electrical maintenance status of high-voltage motors recurring analysis service 1.1. High pressure motor cooling system failure unit used most motors are: JSl4104 6kV 500kW, JSl512-6 6kV 780kW, Y40014 a S 6kV 500kW, YKS560 a 6 10kV 1250kW several motors, the first two are self-ventilated drip-proof, the latter two It is fully enclosed water-cooled. Self-ventilated drip proof motor air vents are not blocked as long, basically no cooling system failure. Fully enclosed water-cooled motor cooling system is divided into two kinds of steel tube heat pipe cooling cycle and aluminum circulating cooling heat. Because I need to ask and production unit process, starting very frequently, mechanical impact force, vibration and cavitation of cooling water, circulating cooling system failure which resulted in two water-cooled motor, and the consequent failure when It happens, mainly for the following aspects: (1). External cooling circuit of the motor is damaged, leading to loss of cooling capacity of the cooling medium is reduced, causing the motor temperature rise; (2). Deterioration due to the cooling water, cooling water deterioration, cooling water impurities corroded pipes, cooling channel blockage, causing the motor to overheat; (3). Cooling of the cooling requirements of high motor cooling tube, requiring good thermal conductivity, so the use of a special aluminum rolling cycle there is a cooling heat pipe heat sink, and because the water box requires a certain strength, so the selection of steel materials, Such water box material is steel, and the cooling heat pipe material is aluminum, resulting in both welding difficult, so the manufacturers design the extruded aluminum heat pipe flaring Riveting steel casing in the water, after years of operation After dust in the air, water impurities and minerals to make aluminum motor heat pipe cooling cycle flared Riveting junction severe oxidation, corrosion, vibration caused by motor plus riveting adrift, cooling water infiltration at the junction produce holes, resulting in aluminum circulating cooling heat pipe leaks, leaking water drops directly on the stator of the motor, the motor will cause "blasting" accident. 1.2. High-voltage electrical insulation resistance is low, the winding insulation breakdown or lead to ground fault high voltage motors due to the humid environment, the motor insulation damp, insulation resistance value does not meet code requirements; the magnetic substance falls coil surface, a drilling phenomenon, leading to stator winding insulation breakdown to ground; motor lead position in the core back of the hot zone, after a long run Insulation Aging, lead rubber insulation crisp, deterioration and peeling, force and mechanical vibration making the bottle broken or loose electrical wire, causing the motor Lead is bad or even break and sharp arc discharge phenomenon. 1.3. High-voltage motor stator wedges loose ends lashing Trouble motor stator wedges loose end winding lashing bad, when the motor generates vibration in up and running, the coil relative displacement motor electromagnetic loud, discharge phenomenon occurs. 1.4. High pressure rotor faults of high voltage motors frequent starts and generation of the overload operation thermal effect force, electromagnetic force and mechanical centrifugal force caused by alternating stress caused by motor squirrel cage rotor shorting ring and copper strips welded at the open welding, rotor bars in slots in the loose, running in the stator current swing big, intense vibration motor, the motor sound increases and the emergence of electromagnetic discharges 1.5. High-voltage high-voltage motors motor bearing failure bearing maintenance is not installed correctly, with tolerance too tight or too loose, grease Add inappropriate. Runtime bearing heating, high temperature, vibration, bearing abnormal sound at a loud sound.