Information Technology Reference
In-Depth Information
These patch cords are truly a mess to deal with, leading some to try to avoid
their use entirely and use semi-permanent cross-connect wire instead. In LAN
wiring, flexible equipment cords are often used between a patch panel and the LAN
hub. Many hub ports must be connected with an 8-pin modular cord, unless they
are equipped with mass-terminated connectors, such as the 50-pin telco connector.
Thus, the use of stranded-wire cords may be unavoidable.
How you handle cable management will be a function of the size of your TR
and how it is laid out. If you have a small, wall-mounted wire termination system
with a few wall-mounted hubs, you may be able to deal with the cables by securing
the station wires with tie wraps and standoffs, running cross-connects (if any)
around standoff posts or through cable rings, and letting the patch or equipment
cords droop (neatly, we hope). On the other hand, if you have a large facility, or
have equipment and wiring devices that are mounted in floor racks, you should use
a system of cable trays, panels, raceways, and brackets that routes all types of cable
and keeps them very neat. There is nothing more troublesome than having to pick
your way through a curtain of patch cords to find a patch jack. There are much bet-
ter ways to install your cable and cords, and we will cover some of them here.
We should caution you first that using tie wraps (cable ties) that are excessively
tightened can cause performance problems on Category 5e/6 wiring and should be
avoided. However, relatively loose ties that do not distort the cable jacket should be all
right. The effect is cumulative, so 20 tie wraps are worse than five. You can use a new
type of wrap made with hook-and-loop mesh (Velcro-type) in lieu of traditional nylon
tie wraps. This new wrap is wider, so it does not pinch the cable as badly. It is also eas-
ily removable so that new cables can be added without adding tie-wrap clutter.
Standoffs and Distribution Rings
The most basic accessories for wire management are plastic standoffs and plastic or
metal distribution rings. Some examples of standoffs are shown in Fig. 7.12. The
plastic standoffs (sometimes called
wire spools
or
mushrooms
) are designed to hold
cables or cross-connect wires underneath the outer lip (which gives it the mushroom
look). Wires are wrapped over a standoff, or down the side of a line of standoffs
and routed to their destination. The wire is usually bent around the post very
slightly to give the wire a “set” and hold it in place. Tie wraps may also be used to
hold wires in place, subject to precautions applicable to Category 5e/6 use. The
standoffs are hollow and may be secured to the wiring board with a captive wood
screw or machine screw. Standoffs are also supplied without a screw. These devices
are very widely used in cross-connect fields, especially with the 66-style connecting
block, which has little native cable management.
