Introduction to Frequency Converters
The rapid development of technologies and circuit solutions has led to frequency converters becoming not only cheaper but also more compact in recent years, making them accessible to all categories of consumers - from large enterprises to individual households.
Previously, the installation and maintenance of frequency converters were handled only by specialists, but now even non-professionals are starting to get involved. Although detailed instructions and intuitive interfaces help to master the basics of operation, there are still many nuances that are not always covered in the documentation.
Key Points When Using Frequency Converters
Soft Start of the Motor
The frequency converter is primarily designed to ensure a smooth start and stop of the electric motor. This significantly reduces the load on the mechanical and electrical components of the system, which, in turn, extends the lifespan of motors, bearings, and other vital elements. A soft start also helps to reduce electrical loads on the network, particularly by lowering peak values of current and voltage during the motor's startup.
Proper Motor Selection
Quite often, when choosing a frequency converter, non-specialists focus solely on its rated power in kilowatts. However, it is also important to pay attention to other parameters, such as rated current (in amperes) and voltage (in volts), as this can affect the overall efficiency of the drive.
Drive Operation Mode at Low Speeds
In many cases, motors and converters operate under conditions where most of the working cycle occurs at a reduced rotation frequency (less than one-third of the rated value). This is especially true for pumps and fans. In such situations, if no additional cooling is organized, there is a risk of overheating the windings of the motor. It is recommended to implement forced or natural ventilation or install additional radiators to improve heat dissipation.
Electromagnetic Compatibility
It is important to consider that an electrical interference source may be located near the installations. Quality frequency converters usually have protection against major types of interference, but for additional reliability, it is recommended to install cable communications such that they intersect at right angles.
Backward Rotation of Fans
In most fan systems, backward rotation of inactive fans can occur due to the influence of air streams. To prevent this, it is recommended to activate the DC braking function of the motor before starting. In more expensive models of frequency converters, a function is offered to synchronize the rotation frequency of the motor with the fan shaft.