Kevin P. Fleming wrote:
Rich Adamson wrote:
Oh, and if shielded T1 cable is used, the shield at each end of the
cable must be grounded. (Let's see how many can figure out how to do
that via an rj45 plug. ;)
You use shielded plugs and jacks, of course :-) That is why the
TE405P/TE410P have shielded jacks (as of about a year ago, IIRC). The
retail packaged cards even ship with four shielded cables included!
Excellent!
Minor point: isn't it safer to only ground the shield on one end?
Best practices suggests IT/telco equipment racks throughout a building
share a single grounding system (and not with 24 ga cable). Likewise,
grounding of both ends of a T1 (eg, shield) is considered best practice.
Treat a T1 cable as no different then a transmission line with a 1.5mhz
RF signal.
If rack grounding is totally ignored (which probably happens
frequently), there is a possibility of a ground loop created through the
T1 shield. But, the root-cause is the lack of rack grounding, not
leaving one end of a T1 cable ungrounded.
For safety, also think about the number of devices that are produced
with poor power supplies, hot chassis, etc. Seen (and felt) several of
those. ;)
R.
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