The power is not connected: If the power is not connected or the contact is poor, the motor will not rotate. At this time, the electrician should check the switch, fuse , various contacts and terminals, and gradually troubleshoot the fault for repair;

During startup, the fuse is blown and causes no rotation: find out the cause of the fuse, troubleshoot, and install a fuse of the same specification according to the motor capacity;

The setting current of the over- current relay is too small and causes it not to rotate: at this time, it should be increased appropriately;

The load is too large or the transmission structure is jammed, causing it to not rotate: choose a larger capacity motor or reduce the load, and check the transmission mechanism;

The stator or rotor winding is broken and does not rotate: open the junction box and use the ohm scale of the multimeter to check whether the motor winding is broken (wire is broken). If there is a broken circuit, the resistance value will be abnormal. You need to open the motor to further check the disconnection point and make a good connection;

Short circuit between turns of the stator winding: The winding of the motor is composed of many coils. When the coils are short-circuited, the motor may not rotate. You can use a multimeter to check to find the two sides of the short circuit. Disassemble the motor and connect the connecting wires of each coil of one phase. Disconnect, check short circuit points in groups, and re-insulate after detection.

The stator winding is short-circuited to the ground: Use a megger or multimeter to check and find out the grounding winding. If the insulation is damaged, re-insulate it. If it is serious, the winding can be replaced; if it is damp, you can dry it and then apply a layer of insulating paint;

Stator winding wiring error: Disassemble the motor to find the error and rewire it.

Poor contact of the rotor slip ring of the wound motor: Correct the slip ring indication and adjust the carbon brush pressure.

The reason why the three-phase asynchronous motor shell is electrified may be: This means that your motor shell is not grounded or is damaged. After the grounding device is damaged, the windings of the motor are affected by moisture and the insulation is aged, resulting in poor insulation and leakage, or the lead wire is connected to the motor shell. On.

In this case, first check whether the grounding device of the motor is intact and reground it. Dry the motor and replace windings with severely aged insulation.

The reason why the three-phase asynchronous motor shell is electrified may be: This means that your motor shell is not grounded or is damaged. After the grounding device is damaged, the windings of the motor are affected by moisture and the insulation is aged, resulting in poor insulation and leakage, or the lead wire is connected to the motor shell. On.

In this case, first check whether the grounding device of the motor is intact and reground it. Dry the motor and replace windings with severely aged insulation.

There is a buzzing sound in two-phase operation: restart after shutdown. If it is two-phase operation, the motor will no longer rotate. Find out the cause of the missing phase and eliminate it;

Three-phase current imbalance: Check the cause of the three-phase power imbalance. Is it caused by the power supply voltage or the motor itself? Find out the cause and eliminate it;

The stator rubs against the rotor: correct the rotor shaft, file away the protruding parts of the stator or rotor core, or replace the bearings;

Some screws or parts are loose: tighten each screw and the black gold coupling bolt;

Vibration: Check whether the foundation is stable, tighten the motor foot screws and check the balance of the rotor;

The fan blades collide with the shell: correct the blades and tighten the screws;

The bearing is seriously short of oil: clean the bearing and add new lubricating oil. The capacity should not exceed 70% of the volume;

The fit between the bearing and the shaft is too loose (inner circle) or too tight: Too loose or too tight will cause excess friction, which will increase the temperature of the motor bearing. If the shaft is too loose, it can be nested; if it is too tight, the shaft can be reprocessed to standard size;

The fit between the bearing and the end cover is too loose (outer circle) or too tight: if it is too loose, the end cover is inserted into the sleeve, if it is too tight, it is the standard size for reprocessing;

There is too much or too little lubricating oil in the bearing or the oil quality is poor: add an appropriate amount of lubricating oil or change the oil;

Bearing damage: Replace the bearing.

Excessive load: Overload operation will cause the winding current to increase, causing the temperature to rise and even burn the winding insulation to cause a burnt smell. In this case, a large-capacity motor should be used or the load should be reduced;

Two-phase operation: check fuses, contacts, circuits and troubleshoot;

The motor air duct is blocked: This will lead to poor heat dissipation, resulting in an increase in temperature. Foreign matter such as grease or dust in the air duct should be removed;

The ambient temperature increases: For example, if it is exposed to the sun or there is a heat source in the accessory, shading or cooling measures should be taken at this time;

Short circuit between turns or phases of the stator winding: The short circuit causes the current to surge and the temperature rises, resulting in a burnt smell. At this time, use a multimeter to find the short-circuited winding and correct the short circuit;

The stator winding of the motor is grounded;

The power supply voltage is too high or too low: the high voltage exceeds 10% or the low voltage exceeds the rated 5% (the torque does not increase during heavy load and affects the speed), which will cause the winding current to be too large, destroy the insulation and generate high temperatures, which may burn out the motor; if If the system voltage is low, adjust the transformer tap. If the line is too long, increase the cable cross-section.

The slip ring of the wound motor has excessive sparks

The brush brand or size is inappropriate: the size of the motor is different from the size and shape of the brushes (carbon brushes) used. If they are mixed, it will lead to poor contact and generate excessive sparks;

The slip ring indicates dirt: This dirt may be caused by long-term sparks, wear, etc. The motor may also have grooves after long-term use. These grooves and dirt can also cause poor contact between the carbon brush and the slip ring, resulting in excessive sparks. , it is recommended to polish with fine sandpaper at this time, and use a lathe to polish if necessary.

The brush pressure is too small or too large: loosening caused by too small brush pressure and excessive friction caused by being too tight may cause excessive sparks; it is recommended to adjust the spring pressure.