Filters for motor protection in installations with frequency inverters

Why is the installation of filters at the output of the frequency inverter important and how do they help protect electric motors and prolong their lifespan? What damage can the motor suffer if an output filter is not installed in the inverter? We have summarized it for you below…

Frequency converters (VFDs) use pulse-width modulation (PWM) to change the power frequency of the motors, allowing them to regulate their speed and other parameters.
Although the introduction of variators has resulted in greater energy savings and more precise control of the motors, the length between the VFD and the motor results in possible overvoltages at the motor terminals. To avoid this, the correct selection and use of filters at the output of the variator extends the motor's lifespan and reduces its maintenance costs.

Problems in engines without a filter:
– Damage to the motor's electrical insulation due to high dV/dt, overvoltages, and overheating
– EMI interference in the wiring
– Damage to bearings

Solutions based on the distance between the inverter and the motor:
(the maximum length may vary depending on factors inherent to each installation)
Up to 10 meters: FS/FST impact bars More information
Up to 100 meters: DVT models DVT filters More information
Up to 600 meters: SNF senoid filters More information

Watch this summary video with the main advantages of the filters at the output of the frequency converter for the protection of electric motors.

For more information, consult our technical department about the best solution for your installation:

Tel. (+34) 935 748 206, info@vectorenergy.com