W901 air cooling mechanical and electrical machine overload fault cases

W901 overload fault case 2019 - air cooling mechanical and electrical machine 08 - 12 ( LanFan chemical electrical workshop) Case review: this was a very easy to judge the motor fault, but because it is a vertical machine, plate of the car was easy, winding measurement data and there is no problem, so give us judge fault caused the problem. Hope you seriously study the failure, but also improve the experience of the motor sound judgment fault. Environment is introduced: W901, W3359 two air cooler motors for vertical installation, 11 kw power, rated current of 25. 2A。 The condensate temperature in the air cooler 170 & deg; C, the winter air cooler runtime environment temperature above 110 degrees above. Fault description: on December 11, 2018, electrical personnel Zhang Kun, Chen found plasticizer DBP in substation maintenance motor frequency converter device W901 air-cooling machine trouble light yellow lights, immediately notified plasticizer technology personnel, and ask about interior presence of operation and the abnormal situation, technology personnel reply: no, will then let indoor W901 operation frequency was lowered to 0 hz, the site shall not be started, electrical personnel need power outage, find the reasons. Electrical personnel check the inverter display, display OL1 ( Motor overload) Failures, power outages, tear open the inverter wiring, contained in the telemetry insulation is 550 m from three relatively & Omega; , and resistance to 0. 8Ω , 0. 9Ω , 0. 8Ω , turning normal at the scene. Notify the technology personnel, sending separate test frequency converter. Site operation after start-up, contactor and voice, immediately to process a given 10% opening, frequency according to 4. 7 hz, the opening of a given 30%, 14 hz frequency display, given 100% opening, frequency according to 49. 6 hz, proving that inverter running without exception. After the blackout will motor cable access to boot, but the motor is still not go. But at the moment, inverter OL2 ( The inverter overload) 。 Power outages, the scene to open the box and found cable and terminal is carbonized phenomenon, dismantling cables, dismantling connection piece, clean up the terminal, telemetry insulation is 550 m from three relatively & Omega; Insulation, alternate with 550 m & Omega; Three-phase winding dc resistance to 1. 0Ω , 0. 9Ω 1. 0Ω To determine motor winding is normal. Restore again after connection of commissioning, still OL2 ( The inverter overload) That motor problem. Frequency converter after reset, to commissioning, with current meter to measure three phase current, at 7 hz, the current has reached 25 a, one after the meeting, OL2 ( The inverter overload) Failure, judge problem for the motor. On December 12, 2018, again shake test of insulation, and insulation, winding dc resistance, and similar data with the December 11, 2018, once again, notify the boot process. The start normal, motor has a different tone, stop after dismantling fan cover, a plastic fan has broken open the bearing gland, inside the bearing have serious lack of fuel, to repair motors. Check the part of the cable sheath and insulating sheath has aging fracture. Motor overhaul, found that the motor bearing oil shortage is very serious, burning, there motor rotor bore. Bearing chamber measured within the standard, do not need to brush plating. Failure cause analysis: (1) due to environment temperature is too high, due to the high temperature oil shortage of motor bearing damage, increase the bearing clearance, energized the chamber JiSao friction with the stator, rotor eccentric lead to electricity current increases, the frequency converter for motor overload or inverter overload. Again because of the motor is vertical, electric manual jigger, rotor and stator is not contact, so turning very easily, measuring winding data correctly, so you create the false impression that the motor is no problem to us, to judge fault caused the problem. Second, we often use the cable YJV type heat resistance up to 90 degrees, do not apply in the environment of high temperature, insulating sheath ageing caused by fracture, electrical plastic fan blade is the same situation. Three, because these two devices at the outside of the fence, encroach risky plus high temperature equipment runtime environment, lead to personnel inspection does not reach the designated position, not in time failed to timely find motor bearing is short of oil. Rectification to improve measures: first, in doing the experiment with special air compressor oil, special air compressor lubricant can withstand temperatures up to 110 degree above. According to the experimental use to decide whether to switch to a high temperature bearing again. In the motor fan for metal material 2, from threading pipe junction box ( Hazardous areas are not allowed to have cable joint) Threading pipe to motor cable replacement for high temperature resistant cable junction box. Three, on the two motors regular maintenance once every two years. Four, key inspection of these two motor, control motor bearing sound change, have the opportunity to increase the up and down the ladder.