We are in the process of installing the use of the inverter, it is inevitable because some do not know where to make some wrong installation and use of the inverter, the following article in this article Sinuoer Electric to answer everyone in the installation of the inverter Some mistakes.
Misunderstanding one: In the inverter output circuit connected to the electromagnetic switch and electromagnetic contactor
In practical applications, the inverter needs to be switched to the contactor in some occasions. For example, when the frequency inverter fails, it will switch to the working mode of the power frequency, or when one motor is used and the motor is faulty , The inverter will turn to drag another motor and so on. So many users will think that installing the electromagnetic switch and the electromagnetic contactor in the output loop of the inverter is a standard configuration and it is a safe way to disconnect the power supply. However, in fact, this method has a big hidden danger .
Disadvantages: When the inverter is still running work, the contactor first disconnect, suddenly interrupt the load, the inrush current will make the action of overcurrent protection, rectifier circuit will have a certain impact on the main circuit. Serious, may even cause damage to the inverter output module IGBT. At the same time, with inductive motor loads, the inductive magnetic field energy can not be quickly released, will produce higher voltages, damage to the motor and the connection cable insulation.
Strategy: The output side of the inverter directly connected with the motor cable, the normal start and stop the motor can be triggered by the inverter to control the terminal, so as to achieve the soft start soft stop effect. If it is necessary to use the contactor on the output side of the inverter, the necessary control interlock must be made between the output of the inverter and the contactor action, which ensures that only if the inverter has no output When the contactor can move.
Myth # 2: When the equipment is normally out of service, disconnect the AC input power of the inverter
When the equipment is normally out of service, many users are used to disconnecting the AC input power switch of the frequency converter first, thinking that it will be safer and can also save energy.
Disadvantages: This approach, ostensibly seems to play a role in protecting the inverter from power failure impact. In fact, the inverter is not charged for a long time, coupled with the humidity of the scene environment, will cause the internal circuit board damp occurred slowly oxidation, the gradual emergence of short-circuit phenomenon. This is why the frequency inverter will report a soft fault frequently when it is powered off again after the inverter is powered off for a period of time.
Strategy: In addition to repair the equipment inspection, the inverter should be in a charged state for a long time. In addition, you should also open the upper and lower fan inverter control cabinet, placed in the cabinet some desiccant or automatic temperature and humidity control heater installed to maintain the environment of ventilation and drying.
The above is the inverter is installed in some common errors and some solutions, the next article we will explain some common errors in the use of the inverter and some solutions. For more, please continue to pay attention to Sinol Electric.