Hi
Just after peoples opinions/suggestions on a screen ground location/path.
Please see the attached image, The setup will be powered by a PoE switch - it is connected to an Audio Encoder (AXIS C8033).
The Encoder creates a local 12V supply and this is used to supply (in my case) a microphone (the mic works between 9-18VDC)
The output from the microphone is balanced line level (consumer) and via a 1:1 transformer this is routed into the audio encoder as an unbalanced input.

My question is with regards to screen ground connection point for the multi-core cable from the microphone.
The cable is physically (2 x) 22AWG twisted pairs, each individually foil wrapped and the cable has an overall screen braid (with drain wire).
1 of the pairs is microphone 12VDC & 0VDC and the other pair is for the balanced audio output from the microphone.
The enclosure for the encoder / transformer is plastic so a case screen is not possible.
If I use the 0VDC from the encoder for the screen ground I am curious if this is going to be a bad idea.... any noise I pick up will have a long path through the encoder internals and I presume back down the PoE power wires.
Presenting this noise to the encoders 0VDC feels wrong?
Should I be thinking along the lines of maybe using a common mode choke on the DC power wires? and dare I say no screen?

Best Regards
TS