Is this question difficult? For you, it definitely isn’t difficult

Low voltage, overcurrent, excessive load, phase-to-phase short circuits, poor grounding or neutral connection, etc. I’m not from the repair workshop; this is for reference only.

http://www.google.cn/custom?domains=bbs.hcbbs.com&q=%B5%E7%B6%AF%BB%FA%C9%D5%BB%D9%B5%C4%D4%AD%D2%F2&sa=Google+%CB%D1%CB%F7&sitesearch=bbs.hcbbs.com&client=pub-0712079178777972&forid=1&channel=2085049995&ie=GB2312&oe=GB2312&safe=active&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3BVLC%3A663399%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3A336699%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000%3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BLH%3A50%3BLW%3A110%3BL%3Ahttp%3A%2F%2Fbbs.hcbbs.com%2Ftemplates%2Fdiscuz6%2Fimages%2Flogo.gif%3BS%3Ahttp%3A%2F%2Fbbs.hcbbs.com%3BFORID%3A1&hl=zh-CN There are relevant posts on the forum; you can take a look!

Thank you for your answer. Have you encountered any actual burning incidents in actual production? 2# wgr1201

Thank you for your answer, but it’s a bit too general, and it’s difficult to find information on motor burnout incidents that occur in actual production. 3# liaifeng

Not many of the company’s motors are broken; rather, it’s the pumps that are often damaged. There are also cases where the motors of submersible pumps burn out, usually due to vacuum conditions or blockages.

This topic is too broad; one should pay attention to gathering more information regularly. I don’t have much information available at the moment, so I’ll provide a few examples to get things started. 1. What are the reasons for high motor temperature? How to handle it? The reasons for high motor temperature are: ① Poor insulation and moisture. ②The current is too high; it’s overloaded. ③The motor power cable is short-circuited. ④The motor bearing is not installed properly. ⑤There is too much or too little grease in the motor. ⑥Lack of regular cleaning, resulting in poor ventilation and heat dissipation. Solution: Switch to the backup pump, cut off power, and contact maintenance. 2. Why is it necessary to install a ground wire on the motor? When the insulation of the windings inside the motor is damaged and leakage occurs, the machine casing becomes charged, which can easily lead to electric shock accidents. Installing a ground wire is to direct any leakage current into the ground, thus creating a circuit that ensures personal safety. Therefore, when the operator discovers that the motor grounding wire is damaged or not installed, it should be addressed promptly. 3. What are the reasons for increased motor current? The reasons for increased motor current include: ① High specific gravity or viscosity of the medium. ②High flow rate or head pressure. ③There is debris blocking the impeller. ④The moving part rubs against the stationary part. 4. Why does a motor trip during operation? The reasons for motor tripping are as follows: ① A short circuit in the motor’s windings occurs; due to the high current resulting from this short circuit, the power fuse blows. This results in a loss of power to the control circuit, causing the intermediate contactor to disconnect its main contacts in the power line, and thus the motor trips. ②If the grid voltage is low, even if the motor power remains unchanged, the current will increase; the same applies when the pump’s rotor gets stuck. ③Motor overload (e.g., insufficient motor capacity). ④The rotor is stuck. ⑤Clogged balance tube. 5. What are the causes of motor vibration? The reasons for motor vibration include: ① Loose bolts in the motor foundation. ②The motor shaft is bent. ③There is looseness between the cage bars and the end rings on the rotor. ④The fan blades are damaged, resulting in mechanical imbalance of the rotor. ⑤The alignment is poor; the motor shaft and the pump shaft are not aligned. ⑥The motor operates in single-phase mode. 6. What items should be checked for a motor in operation? For a motor that is in operation, the following points should be checked: ① Whether the temperature of the frame and bearings is normal. Shell temperature: Explosion-proof motor ≯95℃ ； Sealed motor ≯80℃. Bearing temperature: Rolling bearings ≯75℃ ； Sliding bearing ≯60℃. ②Check whether the sound emitted by the motor during operation is normal. ③Check the temperature of the motor terminal box. ④Check whether the load current is within the rated range. 7. Under what circumstances should the motor be stopped urgently? The motor must be stopped urgently in the following situations: ① When it endangers personal safety. ②When the motor smokes, emits an odor, or catches fire (this indicates an internal short circuit in the motor). ③When there is significant vibration or axial movement (it may be due to damaged bearing bushings or scuffing). ④The machine or bearing heats up to its limit. ⑤The motor rotates slowly and makes abnormal noises.

Last week, a pump was damaged – the motor made abnormal noises, the temperature reached 120 degrees, and the lubricant melted. After checking the electrical system, it was said that it was due to overload, but the current level wasn’t excessive; I’m confused

Can running out of power cause the motor to burn out? If the load on the motor decreases when there’s no power, then how could it burn out? Where is it blocked? 6# wgr1201

Thank you, sir; your answer is very comprehensive. It would be great to have some examples from actual production; that would help me learn more, * 7# Chi Xiao

The original poster should learn to take the initiative to study on their own; don’t try to find shortcuts whenever there’s a problem – Haichuan is a platform for technical exchanges, not a Q&A site!