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Invitrogen inverter manufacturers teach you how to eliminate soft faults in inverters

Invitro Drive The manufacturer Shanghai Kuan Ying teaches you how to eliminate the soft fault of the inverter. Shanghai Kuanying Automation Equipment Co., Ltd. is an internationally renowned high-tech enterprise, which is affiliated to the high-tech enterprise under the Kuanying Group. Now, with its solid strength and rapid development speed, Shanghai Kuanying Automation Equipment has become the vanguard of the industrial control industry.

1. Detecting overvoltage of the inverter

The overvoltage alarm is generally present at the time of shutdown. The primary cause is that the deceleration time is too short or the brake resistor and brake unit have problems. .

2. Undervoltage

Undervoltage is also a problem that we often encounter in our application. The first reason is because the main circuit voltage is too low (220V series is lower than 200V, 380V series is lower than 400V), the primary reason: the rectifier bridge is damaged or the thyristor three channels are not working properly, which may cause undervoltage problems. The second main circuit contactor is damaged, which causes the DC bus voltage loss to cause undervoltage on the charging resistor. There is also a voltage detection circuit that is undervoltage and presents an undervoltage problem.

3. Detecting overcurrent is a phenomenon in which the frequency conversion alarm is frequent.

3.1 Phenomenon

(1) When restarting, it will trip at a speed. This is a very serious phenomenon of overcurrent. The primary reasons are: load short circuit, mechanical parts are stuck; inverter module is damaged; motor torque is too small and so on.

(2) Jumping on power-on, this phenomenon can't be reset. The main reasons are: bad module, bad drive circuit, and bad current detection circuit.

(3) When restarting, it is not immediately tripped but when it is speeding up, the primary reasons are: the acceleration time setting is too short, the current upper limit setting is too small, and the torque compensation (V/F) setting is compared. high.

3.2 Examples

(1) One LG-IS3-43.7kW inverter will jump “OC” as soon as it starts

Analysis and repair: Open the cover No signs of burnout were found. The online measurement IGBT (7MBR25NF-120) basically has no problem. In order to further distinguish the problem, the high-power transistors measuring 7 cells after the IGBT is removed are well opened and closed. When measuring the driving circuit of the upper half bridge, it was found that there was a significant difference between the other two paths. After careful inspection, it was found that the output pin of one optocoupler A3120 was short-circuited with the power supply, and the three paths after replacement were basically the same. The module is fully powered and installed.

(2) A BELTRO-VERT2.2kW variable power supply will jump “OC” and cannot be reset.

Analysis and repair: First check the inverter module and found no problems. Secondly, there is no abnormality in the driver circuit. The estimated problem is not in this block. Perhaps it is in the over-current signal processing part. After the circuit sensor is removed and powered on, it shows that everything is normal. Therefore, the sensor is broken and a new product is changed. After the load test, everything is normal.

4, detecting the inverter overheating

Overheating is also a common problem. The primary reason is: the surrounding temperature is too high, the fan is blocked, the temperature sensor is not functioning properly, and the motor is overheated

5、Detecting the output imbalance of the inverter

The output imbalance is generally characterized by motor vibration and unstable speed. The primary reason is: the module is bad, the drive circuit is bad, and the reactor is bad.

6. Detecting the inverter overload

Overloading is also one of the frequent problems of the frequency converter jumping. Usually we see the overload phenomenon. In fact, we should first analyze whether the motor overload is still the frequency conversion. The device itself is overloaded. Generally speaking, the motor can be strong because of overload. As long as the motor parameters of the inverter parameter table are set properly, the motor overload is generally not presented. The inverter itself is inferior due to overload. It is very simple to present an overload alarm. We can detect Inverter output voltage, current detection circuit, etc. are easy to issue points to eliminate problems one by one.

The above is the method of eliminating the soft fault of the inverter summarized by Shanghai Kuanying Automation Equipment Co., Ltd. Help, our company will continue to develop energy-saving, efficient, precise and humanized products, with professional and unique industrial control technology, high-quality applicable innovative products and deeply integrated solutions to help users achieve economic transformation and industrial upgrading, and accelerate The pace of internationalization, the use of quality to conquer the world, determined to become a world-renowned professional supplier of intelligent electrical!