Inverter use and maintenance experience
Inverter use and maintenance experience talk: After we repair a large number of inverters, we found that many people have many problems in the use of the inverter, here to discuss with everyone!
A) The choice of frequency converter brand: Do not only look at the price, some inverters have low prices, but the quality and performance are very poor! They cut corners, have a short life span, have few spare parts and are difficult to repair. If you want to replace the entire new circuit board, the maintenance fee will be astronomical; some companies can promise warranty service, but your inverter may have to be transported to a city thousands of miles away. One or two months can be repaired, so when buying the inverter, inquire whether there is maintenance service department nearby; some inverters are brand-name, but they are fragile and have a good use environment (with air conditioners). Quality; Some inverters are equipped with components that are "exclusively exclusive", difficult to buy and expensive, and thus have high maintenance costs. Another problem with poorly performing inverters is that they are very serious when burned, and they have almost no maintenance value. Inverter's failure rate is relatively high, so when purchasing it is necessary to understand whether the maintenance is convenient, whether the inverter module is universal and easy to buy; if a certain type of inverter is used in large quantities, it is best to buy one or two more. Standby; if your inverter is used for simple speed control, please use the economical series with relatively cheap price. If the motor load is heavy and often stop, please select A good capacity or performance of the inverter!
B)---The inverter should not be installed on equipment with vibration (such as injection molding machine, punch press, washing machine), because the main circuit connecting screws in the inverter are easy to loosen, and many inverters are damaged due to this reason!
C) --- Wiring problem: The inverter input is preferably connected to an air switch, the protection current can not be too large to prevent the inverter from burning when the short circuit is not too serious! Must not ground the "N" terminal! Especially the older generation of electricians is the easiest way! Keep the control line as long as possible because it makes the control board susceptible to electromagnetic interference and malfunction! Can also cause damage to the control board! Best shielded wire over 2 meters long! Do not install a high-current, frequently-operating contactor next to the inverter! Because it interferes very much with the frequency converter, it often causes the frequency converter to malfunction (display various faults)! Some people are coveted and convenient, always turn on the start control line (such as Mitsubishi's STF-SD), the inverter starts the motor as soon as the power is transmitted, so the inverter easily burns out the charging resistor because the current flowing through the charging resistor is too large! The ground wire should be well grounded. Otherwise, if the motor is seriously leaky, the live wire will damage the inverter.
D) --- Frequent inverters often do not have to rely on the inverter itself to brake, but to add brake resistors or mechanical brakes, otherwise the inverter is often affected by the motor back EMF, the failure rate will be greatly improved!
E)---If the inverter is running at a low speed (<15HZ), the motor must be equipped with a cooling fan!
F)---Dust and moisture are the most deadly killer of the drive! Especially when the machine stops for a few days, the dust stuck on the circuit board returns to the tide. At this time, the circuit board of the inverter is most likely to be damaged due to ignition. It is best to install the inverter in an air-conditioned room! Or installed in an electric cabinet with a dust filter. It is necessary to regularly clean the dust on the circuit board and the radiator. Before stopping the inverter for a period of time, it is better to use a hair dryer to blow the circuit board!
G) --- Certain brand inverters will not issue overheat protection when the cooling fan is broken! Until the inverter is damaged! So when the fan sounds, it should be replaced!
H) --- Some plants supply power from generators, the voltage is not stable, and the inverter is often damaged! Later, the generator was equipped with a voltage regulator or an overvoltage protection device, which worked well!
I) --- Lightning protection is also very important! Although rarely occurs, when the frequency converter is visited by mine, it will be damaged! The constant voltage water supply frequency converter is most easily struck by lightning because it has a lead lightning pipe that reaches out into the sky!
J)---The interference of the inverter is also a headache. It will make other electronic devices unable to use normally. In this case, the input, output and control lines of the inverter are best to use shielded cables. The shielding layer wiring method can't be wrong, otherwise the effect is opposite. , It is possible to use iron pipes again, install filters, and lower the carrier frequency! We found that if the switching power supply of the inverter is a field effect transistor (such as the K series), the interference will be greater! !
K)---When the inverter is broken, it is best not to give it to someone who does not have maintenance experience! Otherwise, it may be more and more bad (more often than not, it is regrettable). Sometimes it blows quickly. Be sure to check if the module is faulty. Some electricians have no experience. Install a good fast fuse (absolutely cannot use copper wire). The result is that the inverter burns even more. According to our experience, if it is fast, Most of the modules are broken when it is blown, but the bad fast-melting of the module is not necessarily broken! ! Many inverter power modules and rectifier modules can be replaced with each other. If you must buy the original model, you may not be able to buy or high prices!
------- Maintenance of a lot of people suffering from the module: We are in the process of repairing the inverter, often encountered some factories and their own maintenance and then blow up the inverter, and the damage is more serious than the original, more difficult to repair! Upon inspection, they used the repaired module. Maintenance of the module with the instrument is difficult to detect, the parameters are completely normal, but because of its internal wiring is rough, the transistor's sealing grease can not be sealed after opening! Some of these modules can be used for months, and some are blown up at startup! Since the repaired module is opened and reinstalled, careful identification can still be seen! It sticks to the copper piece with 502 glue, it feels hard! The original module's glue is relatively smooth and soft! For the repaired module, because the silicone grease inside is to be cleaned, the module will be hollowed out. The sound produced by tapping the copper plate is different at this time! The damaged module can also be disassembled to see if the wiring is rough. Some fake modules are labeled differently and change from this model to another model! Put a small current into a large current! Even put a low pressure into a high pressure! Today's label printing technology is more and more simulated, but as long as you carefully compare with the original module can still be seen! !
------- We repaired a lot of inverters used in elevators and found that many faults were caused by the high temperature of the working environment and caused the components to be easily aged. The elevator inverters were installed in the top floor control room of the building, often Summer exposure to the sun, plus the frequency converter itself and the braking resistor heat, so that the electrical room temperature is very high, high operating temperature will shorten the life of electronic components! Inverter is more obvious in this regard, so the elevator electrical room in the design of the ventilation in addition to the problem but also pay attention to insulation, such as the wall with hollow bricks, roof multi-layer design, if you can match the air conditioner, the inverter life will be much longer ! If the internal temperature of the inverter is high, the electric cabinet door should be opened. I have seen many manufacturers of electric cabinet design is too small! Just install the inverter! And no cooling fan installed!
------ Elevator inverter repair example: Today repair an Yaskawa 676GL5-15KW elevator inverter, the initial reason is the protection of the 380V/220V transformer fast-melt FU2 (600V/1.5A) blown (short for the cooling fan) 380V/220V transformer short-circuit), the district administrative office did not find out why the electrician used the copper wire instead of the FU2 fast-melting, the copper wire and the nearby circuit board sparked after power on, and the fused copper was sprayed onto the driver board, resulting in two 2BI100NC -120 The power module and driver board are damaged, and the 100A fast fuse is also blown, resulting in significant losses. Therefore, please pay attention to the electrician. In any case, do not use copper wire instead of fast-melt, otherwise the damage to the equipment is usually very tragic and heavy!
------About the daily maintenance of the elevator frequency converter: Now the elevator is controlled by the inverter. When the inverter fails, it will cause inconvenience to many people, and it will also aggravate the management personnel. If there is usually frequency conversion The maintenance of the device can greatly reduce the failure rate of the inverter. After we have repaired a large number of elevator inverters, we have summarized several issues that should be paid attention to during normal maintenance: 1) The temperature of the elevator electrical room cannot be too high, otherwise the inverter components are easy Aging, the best air conditioning, the effect is quite good! 2) To prevent the rain from getting wet, usually when the typhoon is being blown, the window door is blown by the wind and the inverter is splashed into the rain. 3) Lightning protection, this is related to the entire building or the entire community of lightning protection facilities, lightning damaged inverters are generally damaged. 4) The cooling fan of the inverter should clean the dust at regular intervals and find that it has a sound or does not operate. 5) There is abnormal noise in the elevator motor. Usually there is a problem with the inverter. If the three-phase current of the motor is unbalanced, it is better to repair it at this time. When the inverter is completely disabled, the damage may be serious. If you don't have maintenance experience, don't repair yourself. Many people make the inverter worse.
- There is an elevator maintenance company sent a Fujitsu VG5 frequency inverter to repair, he has been repaired twice, it took a few days to burn the module, heavy losses! After inspection, it is because when using wheat latex, the heat-dissipating glue is applied to the bottom plate of the module, resulting in poor heat dissipation of the module. So don't repair yourself if you don't have experience, otherwise you may waste energy, money, and time! There are the following risks to repair yourself (often seen): If you buy a fake module, the driver has a fault but did not find out, install the wrong line, and the screw is not tightened! These can burn the inverter even worse!
—— Elevator manufacturers Please note that some elevator manufacturers have selected the Yaskawa brake unit. After a period of time, it is found that the brake pipe is often bad. Later, after inspection, it was found that the problem was caused by the voltage selection problem. The Yaskawa braking unit must be based on actual conditions. The power supply voltage is selected from the voltage range (shorted by a short contact piece) and is divided into 380V, 400V, 415V, 440V, and 460V voltage ranges to suit different countries. Many people in China are selected in the 380V range, but in many areas the actual voltage is above 400V, so that the brake unit brake much larger, the brake pipe long-term heat and short life, and some with a few months Bad, if the manufacturer chooses 400V file (or 415V) from the beginning, when the power supply voltage is 380V, it does not affect the use of the elevator!
------ There are a lot of fake modules. The following is a true/false comparison of the 2MBI100NC-120 module. The left one is false. The fake module is difficult to measure with the instrument. If you suspect that your module is false, you can see it. Look, the wiring is very rough and the working life is very short.
This is an elevator company in Shenzhen to purchase the module to repair the inverter on the street. The result was that the inverter was sent to us for repair after being completely destroyed. Therefore, if there is no experience, do not repair the inverter by yourself. Otherwise, sometimes it will cause serious damage. !
------ Mitsubishi PM50RSA120 second-hand module (module PM75CSA120, SP50Z6C, SP75Z6C also the same) is now difficult to find, you can also use PM50RHA120 substitute, their biggest difference is that the former's upper half-bridge drive pin is a set of four pins, the latter It is a group of three needles. The second pin of the PM50RSA120 four-pin group is the detection signal output, and the function of the last pin (19-pin) of the lower half-bridge drive is repeated. Many inverters do not use the function of this pin, so the upper half bridge of the PM50RHA120 module is used. The three pins of the drive can be inserted into the 1, 3, and 4 pin positions of the half bridge drive of the PM50RSA120 module. Of course, the pin position should be tilted.
------- How to learn to repair the drive: Many people call to ask how to learn to repair the drive, in fact, learn to repair the drive is not difficult, as long as you have a bit of electronic knowledge, a little understanding of the principle of the drive, and soon Learn to repair the inverter, but the problem is that you want to repair the inverter quickly and well! You must have a considerable amount of experience and repair parts! Experience to accumulate for many years, but also to pay a considerable price! You usually have to burn a lot of inverters to learn a little unforgettable experience! There are many inverter brands! The reasons for the change are ever-changing! There are no books to check! Sometimes it takes a long time to find out, you have to have patience and confidence! It's best to go to the inverter company to soak a few years! It's okay if the salary is low! Another problem is that the accessories are hard to find! You'd better accumulate some common components. You need to figure out which components are interchangeable. In order to reduce the cost, you need to use the old modules to maintain the inverters. However, many of the old modules have problems! Subsequent purchases have been rejected due to unqualified quality of most modules! Therefore, it is also crucial to learn how to check the quality of the inverter module. Most of the unqualified modules are not able to withstand the pressure (except for the repaired modules), so you'd better have a pressure gauge, a 200 yuan or so, and electronic malls generally have Sell! We also often discuss inverter use and maintenance with everyone. There are many inverter maintenance experts we are familiar with because they often buy modules here. If you are interested, you can go up and learn a lot here! Maintenance of the inverter must give the customer warranty, there is a certain risk! Sometimes you lose money! Just start getting prepared!
-------Integrated inverter = one-time inverter: There are several brands of low-power inverter is an integrated design (output module, power supply, push circuit solid sealed together), so that as long as the module has a little Difficulties are also difficult to repair, change the module price is very high (close to the price), so had to be scrapped! In China, there are many objective reasons for the relatively high failure rate of the inverter. Just as one inverter manufacturer has told us that the failure rate of the same type of inverter in China is much higher than that used in Europe and the United States! So when you purchase the inverter, you must consider the problem that the inverter may soon be bad! If your plant is often bad inverter, please do not use a one-time inverter! There have been many factories regret!
Inverter use and maintenance experience talk: After we repair a large number of inverters, we found that many people have many problems in the use of the inverter, here to discuss with everyone!
A) The choice of frequency converter brand: Do not only look at the price, some inverters have low prices, but the quality and performance are very poor! They cut corners, have a short life span, have few spare parts and are difficult to repair. If you want to replace the entire new circuit board, the maintenance fee will be astronomical; some companies can promise warranty service, but your inverter may have to be transported to a city thousands of miles away. One or two months can be repaired, so when buying the inverter, inquire whether there is maintenance service department nearby; some inverters are brand-name, but they are fragile and have a good use environment (with air conditioners). Quality; Some inverters are equipped with components that are "exclusively exclusive", difficult to buy and expensive, and thus have high maintenance costs. Another problem with poorly performing inverters is that they are very serious when burned, and they have almost no maintenance value. Inverter's failure rate is relatively high, so when purchasing it is necessary to understand whether the maintenance is convenient, whether the inverter module is universal and easy to buy; if a certain type of inverter is used in large quantities, it is best to buy one or two more. Standby; if your inverter is used for simple speed control, please use the economical series with relatively cheap price. If the motor load is heavy and often stop, please select A good capacity or performance of the inverter!
B)---The inverter should not be installed on equipment with vibration (such as injection molding machine, punch press, washing machine), because the main circuit connecting screws in the inverter are easy to loosen, and many inverters are damaged due to this reason!
C) --- Wiring problem: The inverter input is preferably connected to an air switch, the protection current can not be too large to prevent the inverter from burning when the short circuit is not too serious! Must not ground the "N" terminal! Especially the older generation of electricians is the easiest way! Keep the control line as long as possible because it makes the control board susceptible to electromagnetic interference and malfunction! Can also cause damage to the control board! Best shielded wire over 2 meters long! Do not install a high-current, frequently-operating contactor next to the inverter! Because it interferes very much with the frequency converter, it often causes the frequency converter to malfunction (display various faults)! Some people are coveted and convenient, always turn on the start control line (such as Mitsubishi's STF-SD), the inverter starts the motor as soon as the power is transmitted, so the inverter easily burns out the charging resistor because the current flowing through the charging resistor is too large! The ground wire should be well grounded. Otherwise, if the motor is seriously leaky, the live wire will damage the inverter.
D) --- Frequent inverters often do not have to rely on the inverter itself to brake, but to add brake resistors or mechanical brakes, otherwise the inverter is often affected by the motor back EMF, the failure rate will be greatly improved!
E)---If the inverter is running at a low speed (<15HZ), the motor must be equipped with a cooling fan!
F)---Dust and moisture are the most deadly killer of the drive! Especially when the machine stops for a few days, the dust stuck on the circuit board returns to the tide. At this time, the circuit board of the inverter is most likely to be damaged due to ignition. It is best to install the inverter in an air-conditioned room! Or installed in an electric cabinet with a dust filter. It is necessary to regularly clean the dust on the circuit board and the radiator. Before stopping the inverter for a period of time, it is better to use a hair dryer to blow the circuit board!
G) --- Certain brand inverters will not issue overheat protection when the cooling fan is broken! Until the inverter is damaged! So when the fan sounds, it should be replaced!
H) --- Some plants supply power from generators, the voltage is not stable, and the inverter is often damaged! Later, the generator was equipped with a voltage regulator or an overvoltage protection device, which worked well!
I) --- Lightning protection is also very important! Although rarely occurs, when the frequency converter is visited by mine, it will be damaged! The constant voltage water supply frequency converter is most easily struck by lightning because it has a lead lightning pipe that reaches out into the sky!
J)---The interference of the inverter is also a headache. It will make other electronic devices unable to use normally. In this case, the input, output and control lines of the inverter are best to use shielded cables. The shielding layer wiring method can't be wrong, otherwise the effect is opposite. , It is possible to use iron pipes again, install filters, and lower the carrier frequency! We found that if the switching power supply of the inverter is a field effect transistor (such as the K series), the interference will be greater! !
K)---When the inverter is broken, it is best not to give it to someone who does not have maintenance experience! Otherwise, it may be more and more bad (more often than not, it is regrettable). Sometimes it blows quickly. Be sure to check if the module is faulty. Some electricians have no experience. Install a good fast fuse (absolutely cannot use copper wire). The result is that the inverter burns even more. According to our experience, if it is fast, Most of the modules are broken when it is blown, but the bad fast-melting of the module is not necessarily broken! ! Many inverter power modules and rectifier modules can be replaced with each other. If you must buy the original model, you may not be able to buy or high prices!
------- Maintenance of a lot of people suffering from the module: We are in the process of repairing the inverter, often encountered some factories and their own maintenance and then blow up the inverter, and the damage is more serious than the original, more difficult to repair! Upon inspection, they used the repaired module. Maintenance of the module with the instrument is difficult to detect, the parameters are completely normal, but because of its internal wiring is rough, the transistor's sealing grease can not be sealed after opening! Some of these modules can be used for months, and some are blown up at startup! Since the repaired module is opened and reinstalled, careful identification can still be seen! It sticks to the copper piece with 502 glue, it feels hard! The original module's glue is relatively smooth and soft! For the repaired module, because the silicone grease inside is to be cleaned, the module will be hollowed out. The sound produced by tapping the copper plate is different at this time! The damaged module can also be disassembled to see if the wiring is rough. Some fake modules are labeled differently and change from this model to another model! Put a small current into a large current! Even put a low pressure into a high pressure! Today's label printing technology is more and more simulated, but as long as you carefully compare with the original module can still be seen! !
------- We repaired a lot of inverters used in elevators and found that many faults were caused by the high temperature of the working environment and caused the components to be easily aged. The elevator inverters were installed in the top floor control room of the building, often Summer exposure to the sun, plus the frequency converter itself and the braking resistor heat, so that the electrical room temperature is very high, high operating temperature will shorten the life of electronic components! Inverter is more obvious in this regard, so the elevator electrical room in the design of the ventilation in addition to the problem but also pay attention to insulation, such as the wall with hollow bricks, roof multi-layer design, if you can match the air conditioner, the inverter life will be much longer ! If the internal temperature of the inverter is high, the electric cabinet door should be opened. I have seen many manufacturers of electric cabinet design is too small! Just install the inverter! And no cooling fan installed!
------ Elevator inverter repair example: Today repair an Yaskawa 676GL5-15KW elevator inverter, the initial reason is the protection of the 380V/220V transformer fast-melt FU2 (600V/1.5A) blown (short for the cooling fan) 380V/220V transformer short-circuit), the district administrative office did not find out why the electrician used the copper wire instead of the FU2 fast-melting, the copper wire and the nearby circuit board sparked after power on, and the fused copper was sprayed onto the driver board, resulting in two 2BI100NC -120 The power module and driver board are damaged, and the 100A fast fuse is also blown, resulting in significant losses. Therefore, please pay attention to the electrician. In any case, do not use copper wire instead of fast-melt, otherwise the damage to the equipment is usually very tragic and heavy!
------About the daily maintenance of the elevator frequency converter: Now the elevator is controlled by the inverter. When the inverter fails, it will cause inconvenience to many people, and it will also aggravate the management personnel. If there is usually frequency conversion The maintenance of the device can greatly reduce the failure rate of the inverter. After we have repaired a large number of elevator inverters, we have summarized several issues that should be paid attention to during normal maintenance: 1) The temperature of the elevator electrical room cannot be too high, otherwise the inverter components are easy Aging, the best air conditioning, the effect is quite good! 2) To prevent the rain from getting wet, usually when the typhoon is being blown, the window door is blown by the wind and the inverter is splashed into the rain. 3) Lightning protection, this is related to the entire building or the entire community of lightning protection facilities, lightning damaged inverters are generally damaged. 4) The cooling fan of the inverter should clean the dust at regular intervals and find that it has a sound or does not operate. 5) There is abnormal noise in the elevator motor. Usually there is a problem with the inverter. If the three-phase current of the motor is unbalanced, it is better to repair it at this time. When the inverter is completely disabled, the damage may be serious. If you don't have maintenance experience, don't repair yourself. Many people make the inverter worse.
- There is an elevator maintenance company sent a Fujitsu VG5 frequency inverter to repair, he has been repaired twice, it took a few days to burn the module, heavy losses! After inspection, it is because when using wheat latex, the heat-dissipating glue is applied to the bottom plate of the module, resulting in poor heat dissipation of the module. So don't repair yourself if you don't have experience, otherwise you may waste energy, money, and time! There are the following risks to repair yourself (often seen): If you buy a fake module, the driver has a fault but did not find out, install the wrong line, and the screw is not tightened! These can burn the inverter even worse!
—— Elevator manufacturers Please note that some elevator manufacturers have selected the Yaskawa brake unit. After a period of time, it is found that the brake pipe is often bad. Later, after inspection, it was found that the problem was caused by the voltage selection problem. The Yaskawa braking unit must be based on actual conditions. The power supply voltage is selected from the voltage range (shorted by a short contact piece) and is divided into 380V, 400V, 415V, 440V, and 460V voltage ranges to suit different countries. Many people in China are selected in the 380V range, but in many areas the actual voltage is above 400V, so that the brake unit brake much larger, the brake pipe long-term heat and short life, and some with a few months Bad, if the manufacturer chooses 400V file (or 415V) from the beginning, when the power supply voltage is 380V, it does not affect the use of the elevator!
------ There are a lot of fake modules. The following is a true/false comparison of the 2MBI100NC-120 module. The left one is false. The fake module is difficult to measure with the instrument. If you suspect that your module is false, you can see it. Look, the wiring is very rough and the working life is very short.
This is an elevator company in Shenzhen to purchase the module to repair the inverter on the street. The result was that the inverter was sent to us for repair after being completely destroyed. Therefore, if there is no experience, do not repair the inverter by yourself. Otherwise, sometimes it will cause serious damage. !
------ Mitsubishi PM50RSA120 second-hand module (module PM75CSA120, SP50Z6C, SP75Z6C also the same) is now difficult to find, you can also use PM50RHA120 substitute, their biggest difference is that the former's upper half-bridge drive pin is a set of four pins, the latter It is a group of three needles. The second pin of the PM50RSA120 four-pin group is the detection signal output, and the function of the last pin (19-pin) of the lower half-bridge drive is repeated. Many inverters do not use the function of this pin, so the upper half bridge of the PM50RHA120 module is used. The three pins of the drive can be inserted into the 1, 3, and 4 pin positions of the half bridge drive of the PM50RSA120 module. Of course, the pin position should be tilted.
------- How to learn to repair the drive: Many people call to ask how to learn to repair the drive, in fact, learn to repair the drive is not difficult, as long as you have a bit of electronic knowledge, a little understanding of the principle of the drive, and soon Learn to repair the inverter, but the problem is that you want to repair the inverter quickly and well! You must have a considerable amount of experience and repair parts! Experience to accumulate for many years, but also to pay a considerable price! You usually have to burn a lot of inverters to learn a little unforgettable experience! There are many inverter brands! The reasons for the change are ever-changing! There are no books to check! Sometimes it takes a long time to find out, you have to have patience and confidence! It's best to go to the inverter company to soak a few years! It's okay if the salary is low! Another problem is that the accessories are hard to find! You'd better accumulate some common components. You need to figure out which components are interchangeable. In order to reduce the cost, you need to use the old modules to maintain the inverters. However, many of the old modules have problems! Subsequent purchases have been rejected due to unqualified quality of most modules! Therefore, it is also crucial to learn how to check the quality of the inverter module. Most of the unqualified modules are not able to withstand the pressure (except for the repaired modules), so you'd better have a pressure gauge, a 200 yuan or so, and electronic malls generally have Sell! We also often discuss inverter use and maintenance with everyone. There are many inverter maintenance experts we are familiar with because they often buy modules here. If you are interested, you can go up and learn a lot here! Maintenance of the inverter must give the customer warranty, there is a certain risk! Sometimes you lose money! Just start getting prepared!
-------Integrated inverter = one-time inverter: There are several brands of low-power inverter is an integrated design (output module, power supply, push circuit solid sealed together), so that as long as the module has a little Difficulties are also difficult to repair, change the module price is very high (close to the price), so had to be scrapped! In China, there are many objective reasons for the relatively high failure rate of the inverter. Just as one inverter manufacturer has told us that the failure rate of the same type of inverter in China is much higher than that used in Europe and the United States! So when you purchase the inverter, you must consider the problem that the inverter may soon be bad! If your plant is often bad inverter, please do not use a one-time inverter! There have been many factories regret!