What is the distance limitation on Category 6 Shielded Twisted Pair? I will need it to support 100 mbps and 1gbps.
The cable is already in, and I did not choose to use it. I just want to make sure it's going to work.
Thanks in Advance!
100m, just like anything else.
I wonder if its grounded properly?
I doubt it. The people who installed it are inexperienced and underqualified.
What are the ramifications of it not being grounded properly?
I doubt you have shielded cable, it is almost certainly screened (ScTP vs STP).
Anyway, in theory an ungrounded shield may pick up electromagnetic interference and interfere with the operation of your network (the ungrounded shield will act as an antenna).
However, this requires lots of electromagnetic noise, you'd need to run the cabling near industrial transformers/motors/etc to have any chance of even being slightly affected (Ethernet is very tough). (Although, you could be in a unique circumstance, such as near a high power radio transmission tower).
Under normal circumstances, you will probably not have any problems.
That's what I wanted to know. It is in fact shielded. I cut the shielding away myself to punch down the cable to the patch panels. This is in an office building and runs under a raised floor. It does not go near any high voltage or other sources of strong EM fields. So, I'm guessing that means that we'll be alright.
What about the capacitance of the shielding causing electric shock to users/equipment? I read some theory about this...but I wanted to know if there is anything to worry about -- in the real world.
The cable is only part of the "link" of a "Channel" in the horizontal cable run. To qualify the bandwidth capicity you must also consider the Workstation Jack and the Patch Pannel Jack, not to mention the patch cords and workstation cordage. The end of the patch cord thru the patch panel thru the horizontal cable to the workstation jack to the end of the workstation cord is what will connnect to your active electronics, that end to end connection makes up the channel. The best way to verify the capicity of the cable is to put it under a test as defined by the EIA/TIA .
It will not be effectivly screened. In some cases it might be worst that if it isn't grounded at all or you had used UTP.
snipped-for-privacy@gmail.com wrote in part:
I'm very leery of people who ask about distance limitations. unless they mention aircraft hangers, they're usually talking about interbuilding runs. That's a no-no over copper due to lightening damage (differential ground potential).
-- Robert
JebediahSpringfield wrote in part:
Most likely so, but EM is not from voltage but from current. Especially erratically varying current. Arc welders, X-Ray machines and motors (especially frequent start-stop like elevators) have been identified as culprits.
Ground potential differences are a real risk, and one reason that STP (and ScTP) is avoided in N.America. The risk is entirely dependant on the building's electrical system. Isolated ground is best, but raceway/conduit can be acceptable if properly installed/maintained. (HA!) It may be best to bond the shield to ground at one end, and tie the other end to ground through a capacitor (or resistor).
-- Robert
I was specifically asking because I had heard the maximum suggested distance with STP was very short -- like 30 meters -- due to the shielding of the cable. From what I gather from other folks who have contributed to this thread, my initial information was incorrect.
We are talking about wiring inside commerical office space all on one floor. There are no runs more than 100 meters and no runs going outside.
Robert Redelmeier wrote:
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