1. Look: The normal operation of the motor has a great relationship with the surrounding environment. Therefore, in the process of daily inspection, check the water leakage and dripping conditions around the motor (which will cause the low insulation of the motor to form a breakdown and cause burnout), check whether there are objects that affect the ventilation and heat dissipation environment around the motor, and at the same time, it is also very important to regularly monitor the current size and change of the motor operation. In order to ensure the cooling and heat dissipation of the motor, the external part of the motor is treated at a high frequency and at regular interval, although the dirt of the end cover and fan blades of the electric fan seems to have little effect, in fact, it accounts for a large proportion of the daily protection of the motor.
2. Touch: Inspectors with rich experience can judge the operation status of the motor by touching their hands. Rome was not built in a day, and the accumulation that has been experienced over a long period of time is also an important part of the daily inspection and protection of electric motors. If the overall temperature of the motor is higher than the normal operating temperature, it is necessary to check the load, assembly and ventilation of the motor in combination with the motor operating current, and when the bearing condition is good, the temperature at both ends will be lower than the temperature of the intermediate winding section.
3. Measurement: When the motor stops working, it is necessary to measure the insulation resistance of each phase or relative of the motor with an insulation meter at regular intervals (preferably every month), and find the insulation defects in time by comparing with the results of the previous month's test. Taking a three-phase asynchronous motor as an example, the unbalance of the measured three-phase resistance should not exceed 2%, and when the insulation resistance is checked, if it is lower than 5MΩ, it is necessary to analyze the cause of this abnormal condition. Check whether the insulation is damp, or whether the insulation of the windings is not good and the grounding is formed. If the three-phase resistance balance is not significantly affected by the bridge test, it is purely insulation moisture, then after boring treatment, re-run the motor to see if the condition returns to normal, if the stator three-phase resistance is unbalanced, the three-phase of the motor coil has been found to be connected to the ground withstand voltage test and turn-to-turn test. Unless there are special circumstances, do not turn off the heating switch of the motor equipped with electric heating. If the motor is found to be soaked in water, the motor should be broken and the rotor should be extracted, and then dried with compressed air, and then baked from both ends of the motor stator with a baking lamp until the motor is properly insulated.
4. Listening: Distinguishing the sound of motor operation is also an important part of motor inspection and protection. Since the machine room can be very noisy, it is important to use auxiliary tools such as screwdrivers or listening sticks. Close to the two ends of the motor, through a long period of accumulation, we can not only find the bad oscillation of the motor and its driving equipment, but even determine the amount of internal bearing oil. Timely addition of bearing oil or replacement of new bearings and other methods can significantly prevent the blockage, outer circle, and burnout of the motor bearing caused by the lack of oil and dry grinding.
5. Do: The abnormal condition of some motors may not be easy to detect, and the screws, wiring fastening, dismantling and inspection, cleaning and maintenance of the motor according to the maintenance cycle (generally one month) can often cause unexpected effects. If you don't look at it and don't do it, or just look at it and don't do it, it will eventually lead to a problem or accident. For example, the motor wiring stud is loose and the virtual touch causes the lack of phase burnout, and the motor burns out if the lubricating oil is not replenished in time or the contract is replaced. Insist on looking carefully, touching, measuring, doing, listening, the vast majority of problems can be glazed to prevent and prevent, these fundamental protection methods have a great meaning for the protection and daily maintenance of the motor, but this is far from enough, as mentioned earlier, the continuous accumulation of experience, and constantly summarize and refine to improve the ability of personal motor protection and maintenance, is the condition for us to improve the use of motor power and progress output value.
|
More on that
|
Precautions for inverter installation tips - LS power generation
When the line power supply exceeds the driver's kV-A rating by 10 times, add a line reactor.
A 3% impedance line reactor should be used to reduce power line transients caused by capacitor switching, line notching, DC bus overvoltage tripping, and inverter overcurrent and overvoltage conditions. Line...
|
|
Inverter applications and common loads – LS generates electricity
1. Air conditioning load
Office buildings, shopping malls and some supermarkets and factories have central air conditioning, and the electricity consumption of air conditioning is very large during the peak electricity consumption in summer. In hot weather, the electricity consumption of air conditioners in Beijing, Shanghai and Shenzhen accounts for more than 40% of peak electricity. Therefore, with inverter equipment, drag the air conditioning system ...
|
|
The matrix alternating control mode of the inverter - LS power generation
VVVF frequency conversion, vector control frequency conversion, and direct torque control frequency conversion are all one of the AC-DC-AC frequency conversion. One of the disadvantages is that the input power factor is low, the harmonic current is large, the DC circuit needs a large energy storage capacitor, and the regenerative energy cannot be reflected back to the grid, that is, it cannot carry out four-quadrant operation.
|
|
Interference phenomenon that often occurs in LS power inverters
1. As soon as the inverter of the heat exchange station is opened, the pressure transmitter jumps randomly;
2. In the water supply controlled by the inverter, the pressure transformer is used as a signal to collect the pressure, and the pressure transformer is disturbed by the inverter;
3. When the inverter starts the motor, the voltage converter signal is unstable and beats violently;
4. Pressure transformer (4-20 ...
|
|
LS power generation low-voltage universal inverter vector control mode
The method of vector control frequency conversion speed regulation is to change the stator current Ia, Ib, Ic of the asynchronous motor in the three-phase coordinate system, after the three-phase - two-phase change, equivalent to the communication current Ia1Ib1 under the two-phase static coordinate system, and then after the directional rotation according to the rotor magnetic field, it is equivalent to synchronous rotation sitting.
|
|
Advantages of universal inverter - LS produces electricity
Universal inverters are characterized by their versatility. With the development of inverter technology and the continuous expansion of market demand, general-purpose inverters are also developing in two directions: low-cost simple general-purpose LS inverters and high-performance and multi-functional general-purpose inverters. They have the following characteristics:
...
|
|
Parameter setting of LS power inverter
Control method: i.e. speed control, rotation control, PID control or other methods. After adopting the control method, it is generally necessary to carry out static or dynamic identification according to the control accuracy and requirements. Low operating frequency: that is, the small speed of the motor running, when the motor is running at low speed, its heat dissipation function ...
|
|
LS power inverter parts replacement and its requirements
The inverter is composed of many electronic parts, such as semiconductor components, etc., in the operation and maintenance involves the replacement of a related component, because of the composition or physical characteristics of the inverter, it will deteriorate in a certain period of time, so it will reduce the characteristics of the inverter, and even ...
|
|
Inverter maintenance principle analysis and inspection method
Principle analysis is the most fundamental way to eliminate the problem, when other methods are difficult to see the effect, you can start from the basic principle of the circuit, step by step to view, and finally find out the cause of the problem. To use this method, it is necessary to have a clear understanding of the principle of the circuit, and to grasp the various ...
|
|
The difference between inverter and servo - LS produces electricity
An important difference between servo and frequency conversion is that frequency conversion can be without encoder, while servo must have an encoder for electronic commutation.
1. What the two have in common:
The skill of communication servo itself is the learning and application of ...
|
|
Introduction of LS electric power contactors
How LS Contactor Works:
Generally, after the contactor coil is energized, the entire coil current will generate a magnetic field, which will make the core inside have electromagnetic attraction to attract the core, and let their communication contactor point action normally closed contact disconnect, or close, which ...
|
|
The difference between multi-function and general-purpose inverters
Multi-function inverters need to meet the following two conditions:
First, it can be driven by constant torque load, regardless of the type of machine, and can ensure continuous operation even if the load fluctuates greatly. If the above conditions are not satisfied, the inverter will be easy to stop, difficult to start again, and resistant to ...
|
|
Introduction of LS PLC programming software
LS PLC programming software is a professional PLC programming assistant tool, providing excellent interface, which can carry out PLC programming operations such as online modification, debugging and self-diagnosis, packing and debugging, etc., compatible with LG Master-K series and LG MASTER-K series, which can make you in the process of processing in a timely manner.
|
|
Whether the C-type circuit breaker is suitable for the motor circuit - power generation
Type C micro-break is used for general circuits, such as lighting circuits; D-type circuit breakers are used in power circuits such as electric motors, so can C-type micro-breakers be used in motor circuits?
Differences between C-type and D-type discontinuity:
C-type micro-disconnect: with ...
|
|
Dealing with the "transient" fault method of DP slave - LS power generation
Due to poor contact of network connectors, or due to disturbance and other problems, DP networks that have been used for a long time may show a "transient disconnection" situation, that is, occasionally disconnected instantaneously, and quickly recover to normal. If OB86 is not downloaded, the CPU will stop during a transient outage. Now all over the option to download a ...
|
|
Introduction of LS power products
1. Power-related products: medium, low and high voltage electrical products;
(1) Low Voltage Products: Molded Case Circuit Breaker, Air Circuit Breaker, LS Contactor & Overload Relay, Miniature Circuit Breaker, Dual Power Automatic Transfer Switch, Intelligent Motor Protector, Manual Motor Starter, Surge Protection ...
|
|
What are the components of the PLC?
The basic components of PLC for power production:
1. Memory
The memory that registers the architecture software is called the architecture program memory.
The memory that registers the application software is called the user program memory.
2. Power supply
...
|
|
Specifications for the use of power converters
Operating regulations for power inverters
Maintenance & Installation
Work according to the weight of the product.
The number of inverter boxes cannot be stacked in excess of the specified number.
Install according to the user manual.
Do not open the case during transport.
Do not place ...
|
|
The cause of motor burnout caused by inverter - LS generates electricity
In fact, the problems of the motor are not the cause of the motor itself, most of them are caused by the non-standard debugging of the inverter or the wrong inverter motor when the inverter motor is used, etc., mainly due to the following situations:
1. Put the general motor ...
|
|
LS produces common sense of electroplastic case circuit breaker
Now in the process of using molded case circuit breakers, it is necessary to understand the rated current of molded case circuit breakers, and the rated current of molded case circuit breakers generally has more than a dozen, mainly 16A, 25 A, 30A, and the height may reach 630A.
L ...
|
|
Contact
working hours
