Noise filter in inverter driver circuit

[sparky1958]

I have one 1kw single phase and one 5.5kw 3 phase inverter to drive 2 motors.
As the installation is in proximity to 2 smart meter, I'm thinking about the installation of a noise filter. Both motor driver will be switched by a 3 phase contactor.
Does the filter makes any sense , if a 3 phase filter would be installed before the contactor, or has a filter has to be installed directly before each inverter, using in this case a 1 phase and a 3 phase filter
Thanks a lot in advance.