Correct installation, use, and maintenance of electric motors

The correct installation of the motor is necessary to ensure its normal use, and maintenance and upkeep in the later stage are necessary conditions to ensure the service life of the motor. Next, we will talk about the installation, use, and maintenance process of the motor.

1、 Check

1. Carefully check the nameplate data to confirm that the motor model meets the usage requirements.

2. Measure the insulation resistance of the motor winding to the shell with a 500V megohmmeter, and the insulation resistance should be greater than 0.5M Ω.

2、 Installation

1. Electric motors are generally installed in clean and dry indoor areas, with good ventilation around them. The maximum temperature of the ambient air should not exceed 40 ℃, and the minimum temperature should not be lower than -15 ℃, and strong thermal radiation should be prevented.

2. According to the wiring diagram, the connection of the power cord should be tightened. For motors with outgoing cables and wires, they can be directly connected to the power cord, and the joint should be insulated and sealed.

3. When the power cord, phase sequence, and electric coarse wire head are connected correspondingly, the motor rotates clockwise when viewed from the shaft extension end. When changing the direction, simply change the position of the two power lines.

4. The YD series variable stage multi speed asynchronous motor uses the method of changing the lead wire to control the speed change. To ensure the reliability of the operation of the multi speed motor, attention should be paid to the design and operation of the control device. When switching from high speed to low speed, the neutral point of the 2Y connection must be disconnected at the same time as cutting off the power supply to avoid power short circuit when the low-speed winding is connected. During the process of switching from high speed to low speed, the power supply of the low-speed winding must be connected after the motor stops to reduce the impact on the motor and load. When switching the speed, attention should be paid to the direction of the motor.

5. Electric motors can be equipped with couplings, gears, belts, and load mechanical connections. 2-pole motors above 4kw and 4-pole motors above 30kw should not be driven by belts, and the second shaft extension of dual axis extension electric motors can only be driven by coupling. The fit tightness between the coupling, pulley shaft hole, and motor shaft should be appropriate, and it is strictly prohibited to use a heavy hammer to strike during installation. When using a coupling transmission, the centerline of the motor shaft should coincide with the centerline of the load mechanical shaft,

Leave a gap of 1-3mm in the axial direction of the coupling. When using a belt transmission chamber, the centerline of the motor shaft should be parallel to the centerline of the load mechanical shaft, and the centerline of the belt should be perpendicular to the centerline of the shaft.

3、 Grounding

The electric motor must be reliably grounded, and the grounding method, grounding resistance, etc. should comply with the electrical safety management regulations such as the "Grounding Design Specification for Industrial and Civil Power Equipment" and the "Technical Specification for Factory Power Design". The grounding resistance should be less than 4 Ω.

4、 Start up

1. After closing, the motor should be started immediately to reach normal speed and run smoothly. Otherwise, the power should be cut off immediately, and the fault should be checked and eliminated.

2. After starting, pay attention to the motor transmission device, load machinery, voltmeter, and ammeter. If there are any abnormal phenomena, stop the machine immediately.

3. The no-load continuous starting of the motor generally does not exceed 4 times, and the continuous starting after running to the hot state shutdown should not exceed 2 times, otherwise it is easy to burn out the motor.

4. According to the capacity of the power grid, the size of the load, and the power of the motor, a reasonable starting method should be selected. For larger power motors, it is advisable to use the delta method or voltage reduction method for starting.

5、 Run

1. The deviation between the power supply voltage and the rated voltage shall not exceed ± 5%, and the three-phase voltage imbalance shall not exceed 1.5%.

2. The operating current of the motor shall not exceed the rated current on the nameplate, and the three-phase current imbalance shall not exceed 80%, otherwise it may cause the motor to heat up or even burn out.

3. The surface temperature of the motor casing measured with a thermometer should not exceed 80 ℃, and the temperature of the bearings should not exceed 95 ℃

4. Electric motors should be kept clean, dry, and well ventilated regularly, and the air inlet and outlet must be frost free to keep them unobstructed.

5. During operation, the motor emits smoke, experiences severe vibrations, produces abnormal sounds, emits special odors, and experiences a significant decrease in speed; The load device has malfunctioned; In case of personal electric shock, the power should be immediately cut off and the machine should be stopped.

6、 Bearing lubrication

l、 The lubrication of the motor bearings should be good. Generally, after running for 3000-5000 hours, the machine should be stopped for maintenance and the lubricating grease should be replenished or replaced. The lubricating grease grade is ZL-3 lithium based grease.

2. Before using motors that have been stored or unused for more than two years, the lubrication of the bearings should be checked, and if necessary, lubricating grease should be replenished or replaced.

3. Sealed bearings are used for motor bases with a center height of 132 and below, while non sealed bearings are generally used for motor bases with a center height of 160 and above. Sealed bearings do not need to be replaced with lubricating grease during motor use. Non sealed bearings should be regularly replaced with clean lubricating grease. Lubricating grease should be added in an appropriate amount, usually filling 1/3-1/2 of the cavity between the inner and outer rings of the bearing. For motors with grease injection devices, use a lubrication gun to add 3-4 times. Before adding, open the discharge hole or cover plate at the bottom of the bearing cover. After the motor runs for 20 minutes, plug the discharge hole or install the cover plate. When disassembling the discharge hole plug or cover plate, the power should be cut off and the machine should be stopped.

7、 Transportation and Storage

During transportation, the motor should not be affected by moisture, the shaft should not be bumped, and the parts should not be damaged. The storage area should be kept clean, dry, ventilated, free of corrosive gases, and avoid sudden changes in environmental temperature.

8、 Quality Assurance

1. If the motor is damaged or cannot function properly due to manufacturing quality issues within one year from the date of purchase or within one year from our company's production date, provided that the user uses and stores it correctly according to the instructions in the user manual, our company is responsible for warranty repair, replacement, and return.

2. Due to motor malfunctions caused by user reasons, our company can provide motor maintenance services and charge a certain fee according to regulations, generally including the following situations: motor burnout caused by voltage exceeding the rated voltage by ± 5% or overloading operation; Due to a malfunction in the three-phase power supply line of the motor, one or two phases of the stator winding of the motor are burnt out; Equipment accidents caused by failure to install, use, and maintain according to the requirements of the user manual; Unauthorized disassembly or repair of electric motors by users.

9、 Maintenance and repair

When maintaining and repairing electric motors, attention should be paid to environmental protection, ensuring that the repair site is pollution-free and that the motor coils are not removed by burning. For electric motors that have been in use for more than a year, attention should be paid to checking the oil seal and shaft seal ring on the outer side of the motor end cover, as well as the sealing ring on the junction box seat and junction box cover for cracking, deformation, severe wear and other aging phenomena during maintenance. Parts that cannot meet the sealing performance and requirements should be replaced in a timely manner.