The protection of the motor by the power converter mainly includes the following aspects: overvoltage protection, undervoltage protection, overcurrent protection, phase loss protection, inverter protection, overload protection, grounding protection, short circuit protection, overfrequency protection and stall protection.
1. Overvoltage protection
The output of the inverter has a voltage detection function, and the inverter can automatically adjust the output voltage so that the motor cannot withstand overvoltage. Even if the output voltage adjustment fails, and the output voltage exceeds 110% of the normal voltage, the inverter will protect the motor by stopping.
2. Under-voltage protection
When the motor voltage is lower than 90% of the normal voltage, the inverter protection stops.
3. Overcurrent protection
When the current of the motor exceeds 150%/3 seconds of the rated value or 200%/10 microseconds of the rated current, the inverter stops working to protect the motor.
4. Lack of phase protection
Monitor the output voltage. When the output is out of phase, the inverter will sound an alarm. After some time, the inverter will stop to protect the motor.
5. Inverted phase protection
The inverter can only rotate in one direction, and the direction of rotation cannot be set. Unless the user changes the phase sequence of the motor A, B, and C wiring, there is no possibility of inverting the phase.
6. Prevent overload
The inverter monitors the motor current. When the motor current exceeds 120%/1 minute of the rated current, the inverter stops working to protect the motor.
7. Grounding protection
The inverter is equipped with a special grounding protection circuit, which is generally composed of a grounding protection transformer and a relay. When one or two phases are grounded, the inverter will give an alarm. Of course, we can also design it to protect the shutdown immediately after grounding if the user requests.
8. Short circuit protection
After the output of the inverter is short-circuited, it will inevitably cause overcurrent. The inverter will stop the motor in 10 microseconds.
9. Over-frequency protection
The inverter has the function of maximum and minimum frequency limiting, so that the output frequency can only be within the specified range, so as to achieve the overclocking protection function.
10. Stall protection
Stall protection is typically used in synchronous motors. For asynchronous motors, the stall during acceleration is necessarily overcurrent, and the inverter achieves this protection function through overcurrent and overload protection. Stall during deceleration can be avoided by setting a safe deceleration time during commissioning.
|
More on that
|
How to choose LS contactors
The working form of LS contactor:
Generally speaking, 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 make their AC contactor ...
|
|
Interference phenomenon of LS power inverter
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 ...
|
|
Why can't the inverter be equipped with a leakage protector?
When using an inverter, a leakage maintainer must not be used. This is a major criterion for the use of frequency converters.
Some users choose the corresponding leakage maintainer for the inverter when using the inverter. *The result is: the inverter moves together ...
|
|
Manufacturing Automation Terminology – LS Electricity Generation
I/O Points:
When discussing control systems, I/O points are a term that is often heard. It refers to the input/output point, I stands for INPUT, which refers to the input, and O stands for OUTPUT, which refers to the output. The inputs/outputs are for the control system, and the input refers to the ...
|
|
The difference between inverter overload and overcurrent - LS generates electricity
Inverter is an important drive material in modern industrial production, as a power equipment, it is working hard all the time, so its fault rate is very high, and the rapid processing of inverter faults, to ensure the continuity of industrial production, is every maintenance electrician and on-site debugging of electricians.
|
|
The main structure of LS power AC contactor
The operating principle of the contactor is: when the contactor coil is energized, the coil current will generate a magnetic field, and the generated magnetic field will make the static iron core attract the moving core with electromagnetic attraction, and drive the communication contactor point action, the normally closed contact is disconnected, and the normally open contact is closed, and the two are linked. When the coil is de-energized ...
|
|
The function and function of the inverter VFD - LS produces electricity
1. Energy saving
The energy-saving effect of VFD is mainly manifested in the application of fans and water pumps. After the fan and pump load is selected for frequency conversion speed regulation, the power saving rate is 20% - 60%, because the actual power consumption of the fan and pump load is basically proportional to the cubic speed. When users ask for an average ...
|
|
Three-phase motor current is too high - LS power generation
First, the power supply problem
1. The power supply voltage is too high
When the power supply voltage is too high, the motor back electromotive force, magnetic flux and magnetic flux density all increase. Since the magnitude of the iron loss is proportional to the square of the magnetic flux density, the iron loss increases, resulting in overheating of the core. And the increase in magnetic flux causes ...
|
|
Briefly describe LS ABE203b molded case circuit breaker
The circuit breaker is a fundamental low-voltage electrical appliance, which has the function of overload, short circuit and undervoltage maintenance, and has the ability to maintain the line and power supply. Circuit breaker is an indispensable product in electrical safety. Due to different applications, there are molded case circuit breakers, frame circuit breakers, miniature circuit breakers, etc.
|
|
Inverter failure and solution - power generation
1. HW problem
This problem may be a fault unique to LG-IG5 series inverters, and the main causes are as follows:
(1) Damage to the cooling fan. Due to the use of environmental and other factors, the friction of the fan bearing is too large, causing the fan load to be too large and showing H ...
|
|
Inverter circuit structure - LS generates electricity
The main circuit is the power replacement part of the power supply for the asynchronous motor, and the main circuit of the inverter can be roughly divided into two categories: the voltage type is to change the DC of the voltage source to the communication of the DC port of the inverter, and the filter is the capacitor. The current type is to change the DC of the current source to the communication ...
|
|
Principle of electrical equipment maintenance - LS power generation
1. Speak before you start
When it comes to faulty electrical equipment, you should not rush into action, but ask about the passage and phenomenon of the fault.
For unfamiliar equipment, you should also understand the circuit principle and structural characteristics, and follow the corresponding rules. Before dismantling, it is necessary to fully understand each ...
|
|
After the contactor is energized, the start button continuously engages and disconnects ?—— LS generates power
What is the reason why the contactor keeps engaging and disconnecting by pressing the start button after the AC contactor is energized?
In my personal opinion, most of the situation is caused by the wrong coil voltage of the replacement AC contactor, or the purchase of ...
|
|
Several basic functions of the inverter - LS generates electricity
The inverter mainly has the following functions:
1. Soft up
The direct launch of the inverter motor will have a severe impact on the power grid, and it will also have too high requirements for the capacity of the power grid, which is extremely unfavorable to the service life of equipment and power grid circuits.
|
|
The difference between low-speed and high-speed centrifuges – LS generates electricity
Through the rational planning of the structure of the low-speed centrifuge, the hygienic dead angle can be effectively eliminated. The transition of the structural parts is smooth, and the surface is polished. External structural components, fasteners, and rollers are made of stainless steel. The housing is a clamshell type, which allows for thorough cleaning of the interlayer space of the centrifuge housing without the need for a bowl ...
|
|
The lightning protection port of the inverter - LS generates electricity
According to the applied engineering practice, variable frequency drive (VFD) lightning strikes can be roughly divided into direct lightning, induced lightning and conducted lightning. But no matter what form it takes to reach the device, it can be summarized as a lightning surge from the following four parts, which are called lightning protection ports here, with V ...
|
|
LS GTH, GTK series thermal relay models
Thermal Overload Relay GTH-22
GTH series: GTH-22, GTH-40, GTH-85, GTH-100, GTH-150, GTH-220,
GTH-400、GTH-600、GTH-12M、GTH-12MH、GTH-12M、GTH-MH
GTH series: GTH-22, GTH-40, GTH-85 ...
|
|
An internal component of LS's power circuit breaker
1. Auxiliary contact: the contact mechanically linked with the main circuit of the circuit breaker and the closing mechanism is mainly used for the display of the circuit breaker and the closing status, and is connected to the control circuit of the circuit breaker through the opening and closing of the circuit breaker to control or interlock its related electrical appliances. For example, output to signal lights, relays, etc.
|
|
Recommended models for power production contactors
GMC-6 Contactor GMC-6 Rated voltage: 110V/22OV/380V;
GMC-9 Contactor GMC-9 Rated voltage: 110V/22OV/380V;
GMC-12 Contactor GMC-12 Rated voltage: 110V/22OV/380V;
GMC-18 Contactor GMC-18 Rated voltage 110V/ ...
|
|
LS inverter series and its features
LS inverter, the full name of LS communication frequency conversion governor, after supplying a variety of equipment, converts direct current into communication electricity, and changes the voltage and frequency of ordinary power supply input to control the speed of the motor, to meet different industrial needs, and then complete the energy saving and environmental protection of the automation system. ...
|
|
Contact
working hours
