Shielded Ethernet Plugs

[dpslusser]

Shielded ethernet cables with grounded connectors on both ends....is that not the same as grounding both sides of the drain wire in a 4-20mA analog cable?


If I have two control panels on a machine with network switches (grounded to chassis), and a network cable installed between both. Wouldn't you want to only have ONE connector shielded to the switch in order to drain any noise?

Having both shielded could potentially act as a ground loop?


Can anyone provide a white paper to explain?

 

[Pete.S.]

I think you might very well get ground loops. But remember that ethernet is 330 ft / 100m max trunk length. For longer than that or in very difficult environment you'll use fiber.

Regarding ethernet itself (not the shielding) there is an isolation transformer on each end.

 

[dpslusser]

I think you might very well get ground loops. But remember that ethernet is 330 ft / 100m max trunk length. For longer than that or in very difficult environment you'll use fiber.

Regarding ethernet itself (not the shielding) there is an isolation transformer on each end.

That I completely understand.

I did not know that there are isolation transformers on each end. That must not solve interference completely or shielded cable would not exist, correct?

 

[RussB]

Shielded ethernet cables with grounded connectors on both ends....is that not the same as grounding both sides of the drain wire in a 4-20mA analog cable?


If I have two control panels on a machine with network switches (grounded to chassis), and a network cable installed between both. Wouldn't you want to only have ONE connector shielded to the switch in order to drain any noise?

Having both shielded could potentially act as a ground loop?


Can anyone provide a white paper to explain?

Maybe similar but in most cases not really. Internet is "Serial" not current.
Also in most cases it is not end to end but either 'star' or 'loop' where it is generally advantageous to have the drain wire connected all the way through with as few breaks as possible.
Of course there are always exceptions so you need to look at your network and use proper grounding to insure no 'ground loops' and good 'drainage' at all terminations. This would be part of maintaining the CAT5, 5e or 6 directive.