Three-phase LC filters for various frequency converters


EF3LC filters are used to protect the insulation of the motor and to increase its reliability. They also reduce noise level. These filters convert the output voltage signal of PWM inverter for sine wave at the same time eliminating the higher harmonics, which cause additional losses in both the mains cables of the motor and in the same motor. Sinusoidal output current and voltage of the filter allows for using of considerable lengths of cable without the need for shielding and full use of the active power of the drive system.
There is a possibility to produce the filter with various coil terminals like screw terminal blocks, cable lugs or copper bus bars depending on the rated current.
It is important to connect the filter properly, since the direct connection of capacitors to the inverter output may damage the system.
If agreed beforehand, it is possible to manufacture filters with parameters other than those given in the table.

Technical data

Design LC filters are produced according to : EN/IEC 61558-2-20; EN/IEC 60289
Insulation class

F(155oC) - standard

Climatic class
/environmental class

C1/E0 - land design; C2/E1 - maritime design

Ambient temperature 40oC
Protection degree IP 00
Protection class I
Rated frequency 50 Hz
Keying frequency >= 4 kHz
Rated voltage Un = 400 V
Continuous overload
110% In
Instantaneous overload capacity 150% In   1 min/h; 200% In   0,5 min/h
Short circuit voltage 8%
Terminals screw terminal blocks or cable lugs or copper bus bars
Fastening by means of angles