I'm looking at putting in an ethernet STP instalation for our factory but i know that the shield should not be connected at both ends to prevent ground loops (especially in our case: big motors, big power, long distances). I'm concerned standard UTP will be overwhelmed by electrical noise.
I plan to setup a STP patch panel in the control room, with the cables sheild grounded there. Cables will run out from the panel to each machine's control cabinet and connect to the equipment inside. So i have a couple of questions:
First, i'm worried if the computer inside the machines control box has a metal RJ45 jack, if i connect a sheilded patch cable i might end up with fireworks as this will be grounding both ends (the equipment i presume will be grounding the case of its RJ45 jack to its ground). Is this a correct presumption or do electrical equipment isolate their RJ45 jack from their ground?
Second, if the first case is true, can i get RJ45 connectors which can crimp onto STP cable (im thinking of plastic isolated ones as in my first point), or would i be better off putting a socket/plate in the control box and running a patch lead from the plate to the equipment?
Many thanks,
Chris