Do you know how to handle the top 10 motor faults? (II)

Short circuit between iron chips

(1) The iron core laminations are loose, and when the generator is running, the iron core vibrates and damages the insulation; If the insulation of some parts of the iron chip is damaged or the iron core is locally overheated, causing insulation aging, it should be treated according to the original plan.

(2) The edge of the iron chip has burrs or is mechanically damaged during maintenance. Use a fine file to remove burrs, repair damaged areas, clean the surface, and then apply a layer of silicon steel sheet paint.

(3) If there is solder or copper particles short circuiting the iron core, the metal fusion welding points should be scraped or chiseled off, and the surface should be treated properly.

(4) Winding arc short circuit may also cause iron core short circuit. The burnt part should be removed with a chisel and the surface treated.

The generator loses residual magnetism and cannot generate electricity when starting

(1) The frequent loss of residual magnetism after shutdown is due to the fact that the material used for the excitation machine magnetic poles is close to soft steel, resulting in less residual magnetism. When there is no current in the excitation winding after shutdown, the magnetic field disappears. A battery should be prepared and magnetized before power generation.

(2) If the magnetic poles of the generator lose their magnetism, a DC current greater than the rated current (for a short period of time) should be applied to the winding for magnetization, which can restore sufficient residual magnetism.

The temperature of the excitation reactor of the automatic excitation device is too high

(1) The reactor coil is locally short circuited and the reactor should be repaired.

(2) The air gap of the reactor magnetic circuit is too large, and the air gap of the magnetic circuit should be adjusted.

After the generator starts, the voltage cannot rise

(1) The excitation circuit is disconnected, causing the voltage to fail to rise. The excitation circuit should be checked for any broken wires and good contact.

(2) If the residual magnetism disappears and there is no indication on the excitation machine voltmeter, it indicates that the residual magnetism has disappeared and the excitation machine should be magnetized.

(3) The polarity of the magnetic field coil of the exciter should be reversed, and its positive and negative connecting wires should be swapped.

(4) When conducting certain tests during generator maintenance, mistakenly applying reverse DC current to the magnetic field coil resulted in the disappearance or reversal of residual magnetism, and should be re magnetized.