Noise problems in industrial setting

Anyone know the best most effective way to filter out contactor noise and AC motor noise on board? The noise is coming in through at least 2 ways: 1) through the step-down transformer that powers the circuit and 2) through the relays driving the AC motors, etc.

I am powering 240V contactors and AC motors and using the same 240V lines through a step-down transformer and simple switcher power supply to power 5V and 3.3V chips.

The problem is that I get a lot of electrical noise in the system when the contactors turn on or off and when the AC motors turn on/off.

I am running the stepped-down power lines through a common-mode choke. I also have bidirectional TVS diodes across the stepped down voltage and from 5V to gnd and 3.3V to gnd...but still getting noise problems.

Thanks for any help.

I will power the 3.3v and 5v chips from an RC filter if the chips are not taking too much current.