Information Technology Reference
In-Depth Information
FIGURE 6.9
An example of a two-piece modular jack assembly. (Courtesy of AMP Incorporated.)
For that reason, many installers do not recommend screw terminals for any
LAN work. Of course, you do not need to rush around and pull out all of your old
screw terminal plates that might be in your network now. Just remember that they
cannot perform above Category 3 and that old installations may have “space-wired”
station cable that is untwisted or crossed before it even gets to the screw terminals.
Nevertheless, there is still a right and wrong way to terminate wire on screw ter-
minals. Proper wire termination for screw terminals is illustrated in Fig. 6.10. The
screw terminal consists of a screw, two washers, and the plastic post of the jack plate.
The jack's connector wires are normally terminated in an open-end spade lug that is
positioned between the plastic post and the lower of the two washers. To terminate
the station cable, the screw is first loosened. Each station wire's insulation should be
stripped back about 3/8-inch and the bare copper portion wrapped between the two
washers. The wire may be preformed before it is placed into position.
The screw is tightened moderately and electrical contact is made in the sand-
wich made by the washers and the plastic post. The proper direction for the wrap
is clockwise around the screw (and it must be between the two washers). No insu-
lation should be between the washers, and the wire should not wrap back across
itself (to avoid breaking the wire when the screw is tightened). Some installers strip
an inch or more and wrap the wire around the screw (with no overwrap). The excess
