Five mistakes in frequency converter use

Editor:浙江汇迅骏机电技术有限公司 │ Release Time:2021-09-22 

With the continuous improvement of industrial automation, frequency converter has been widely used.  Factory electricians deal with frequency converters almost every day, but are we completely correct about the use and understanding of frequency converters? That's not true. Look at these frequency converters. Have you been fooled? 

Myth 1: The greater the power of the converter, the better? 


Inverter big point, of course, it is good to meet the heavy load can be pulled, the power of the money is also more, so the frequency converter to choose a suitable line, the general domestic frequency converter is bigger than the motor, the imported one is the same as the big, the load load of the heavy load type of frequency converter.  However, it is recommended not to exceed the motor power of the third grade, too large motor protection may have a certain impact! 


Misunderstanding two: inverter is not used or power off? 


Frequency converter belongs to electrical products, so even if you spare, it is better to power on. The standby machine is used in emergency, often not powered on or occasionally powered on. How can you ensure the normal operation of the frequency converter? 


The intermediate components in the frequency converter have electrolytic capacitors, so you do not need to regularly power on the electrolytic capacitor charge and discharge. 


After the inverter is powered on, the inverter only has the current of the control loop, which can be almost ignored and will not cause great loss or greatly reduce the service life. 


Therefore, it is recommended to energize the converter when it is not used for a long time. 


Misunderstanding three: If the frequency converter is used in a dirty environment, dust should be blown every day? 


Environmental dust many people need to clean up every day, in fact, do not need, dust as long as it is not wet generally has little impact, unless you wind duct fan blocked, dust more than one or two months to clean up the dust! However, soot blowing is also acceptable. It is not recommended to carry out under live conditions, which may cause damage to the converter. 


Error four: Inverter output can not add contactor? 


Almost all frequency converter operating instructions point out that the output side of the frequency converter can not be equipped with contactor. Many manufacturers' inverter instructions stipulate that "do not connect the electromagnetic switch and electromagnetic contactor in the output loop". 


The manufacturer's regulation is to prevent contactor action when the inverter governor has an output.  When the inverter is connected to the load in operation, the overcurrent protection loop will be activated because of the leakage current. So, as long as in the frequency conversion governor output and contactor action, to the necessary control interlock, to ensure that only in the frequency conversion governor no output, contactor can move, frequency conversion governor output side can be installed contactor. 


Myth five: As long as the use of frequency converter energy saving? 


Many people think that the torque of two motors does not reach the rated torque state of the motor (frequency, speed is still the same 50HZ), industrial control automation product frequency converter will also play the role of energy saving, this is a wrong view. 


Two identical motors work at the power frequency of 50HZ, one with frequency converter and the other without. At the same time, both the speed and torque are in the rated state of the motor. I believe that most people will think that the one with frequency converter will be energy-saving. In fact, this is also a wrong idea. 


For the same reason, a lot of people think that you can save a lot of power when you're not loaded, but you can't save much power when you're unloaded.