Hello , 

As far we know , maximum distance for motor cable without reactor is 300 meters and with reactors 525 meters both with unscheduled cables  

Is there any other option to increase motor cable like 700 Meters ? anyone have experience with operation VFDs woth such long distance at output ?

Dear Walid,

To increase the lenght of cable betwen the VFD and Motor, your can add a output filter  ( therefore 2 output filter , 1 SIEMENS output filter already configured and an new output filter ) . for exemple schaffner product ( product reference : FN5040-410-99 

https://www.schaffner.com/products/download/product/datasheet/fn-5040-fn-5045-lc-sine-wave-filter-for-motor-drives/

But you need to increse the pulse frequency of your drive ( PWM) to 3 KHZ so that filtre work properly.

Power Module PM240-2 60 Hardware Installation Manual, 01/2019, A5E33294624B AK

The above provides recommendations for cable lengths, which have been tested.

However, a motor cable subject to Pulse Width Modulation, from an inverter drive is far removed from that cable assembly carrying 3 phase sinusoidal supplies.

Cable specification and quality for typical, 4 wire screened cable can be unpredictable when subject to PWM supplies, not only the PWM frequency of 4kHz, but frequencies in the region of Mhz created by the PWM switching frequency. It is this high frequency component which is 'excites' the capacitance of the cable, creating capacitive losses within the cable.

The tables show that unscreened cable can be greater in length, due to lack of screen which is creating an element of the capacitance. The lack of screen however removes the return path for leakage currents from the motor, and it these leakage currents which can interfere with local equipment, being then free to flow throughout the system.

If the project is in the planning stage, then avoid installing motor cable beyond the table specification. Components can be used to mitigate these obstacles, but if the system fails to function at commissioning, over current trips and inverter failures, will be financially damaging.

Or is the inverter drive really necessary at these extended cable lengths?

Thanks for all of your Replies , 

I would like to know you recommendation if i will use 30KW VFD with SINUS Filter P.N: 6SL3202-0AE26-2SA0  to drive 30KW Motor 

What will be the maximum length of motor cable in this case, moreover will this affect the VFD and needs to be increased ?