My PCB gets DC power from a connector, let's say the traces coming from the connector are VIN and RTN. I have a TVS (for ESD protection) between VIN and chassis ground. Should I put another TVS between RTN and chassis ground? RTN becomes board ground after it and VIN pass through a common mode choke. If a TVS is needed on RTN, what reverse working voltage should it have? As low as I can find?
Edit: I can make this question simpler. I know I should put ESD protection (like a TVS) on signal lines that exit the enclosure and even on power lines. But what about ground lines? I am using a bleeder circuit between 'ground' and 'chassis ground' so they are not the same. When they ESD gun the ground line, will it cause ripples on the board ground planes without a TVS?