Wall Plate Jack Considerations | Modular Wall Plates

Modular wall plates are the most common type of wall plate in use for data cabling because they meet the various ANSI/TIA and NEC standards and codes for quality data communications cabling. So modular wall plates have the widest variety of jack types available. All the jacks available today differ based on a few parameters, including the following:

• Wall plate system type
• Cable connection
• Jack orientation
• ANSI/TIA-568-C.2 and -C.3 wiring pattern

Wall Plate System Type

Remember how the type of wall plate you use dictates the type of jacks for that wall plate? Well, logically, the reverse is also true. The interlocking system that holds the jack in place in the wall plate differs from brand to brand. So, when you pick a certain brand and manufacturer for a jack, you must use the same brand and manufacturer of wall plate.

Cable Connection

Jacks for modern communication applications use insulation displacement connectors (IDCs), which have small metal teeth or pins in the connector that press into the individual wires of a UTP cable (or the wires are pressed into the teeth). The teeth puncture the outer insulation of the individual wires and make contact with the conductor inside, thus making a connection. This process (known as crimping or punching down, depending on the method or tool used) is illustrated in Figure 1.

 
Figure 1: Using insulation displacement connectors (IDCs)

Though they may differ in methods, any connector that uses some piece of metal to puncture through the insulation of a strand of copper cable is an IDC connector.

Jack Orientation

Yes, jack orientation. The individual wall plate systems use many different types of jacks, and some of those systems use jacks with positions other than straight ahead (which is the "standard" configuration). These days, a popular configuration is a jack that's angled approximately 45 degrees down. There are many reasons that this jack became popular. Because it's angled, the cable-connect takes up less room (which is nice when a desk is pushed up tight against the wall plate). The angled connector works well in installations with high dust content because it's harder for dust to rest inside the connector. It is especially beneficial in fiber-to-the-desktop applications because it avoids damage to the fiber-optic patch cord by greatly reducing the bend radius of the cable when the cable is plugged in. Figure 2 shows an example of an angled connector.

 
Figure 2: A faceplate with angled RJ-45 and coaxial connectors

Note

Angled connectors are found in many different types of cabling installations, including ScTP, UTP, and fiber optic.

Wiring Pattern

When connecting copper RJ-45 jacks for universal applications (according to the standard, of course), you must wire all jacks and patch points according to either the T568-A or T568-B pattern. Figure 3 shows one side of a common snap-in jack to illustrate that the same jack can be terminated with either T568-A or T568-B color coding. (You may want to see the color version of this figure in the color section.) By comparing Table 1 and 2, you can see that the wiring schemes are different only in that the positions of pair 2 (white/orange) and pair 3 (white/green) are switched. If your company has a standard wiring pattern and you wire a single jack with the opposing standard, that particular jack will not be able to communicate with the rest of the network.

 
Figure 3: A common snap-in jack showing both T568-A and T568-B wiring schemes

Table 1 shows the wiring color scheme for the T568-A pattern. Notice how the wires are paired and which color goes to which pin. Table 2 shows the same for T568-B.

Table 1: Wiring Scheme for T568-A 

Pin Number	Wire Color
1	White/green
2	Green
3	White/orange
4	Blue
5	White/blue
6	Orange
7	White/brown
8	Brown

Table 9.3: Wiring Scheme for T568-B 

Pin Number	Wire Color
1	White/orange
2	Orange
3	White/green
4	Blue
5	White/blue
6	Green
7	White/brown
8	Brown

Number of Jacks | Modular Wall Plates

The first decision you must make when using modular wall plates is how many jacks you want in each wall plate. Each opening in the wall plate can hold a different type of jack for a different type of cable media, if necessary. Additionally, each jack must be served by its own cable, and at least one of those should be a four-pair, 100 ohm, UTP cable.

The number of jacks a plate can have is based on the size of the plate. Fixed-design wall plates mainly come in one size. Modular plates come in a couple of different sizes. The smallest size is single-gang, which measures 4.5″ high and 2.75″ wide. The next largest size is called double-gang, which measures 4.5″ by 4.5″ (the same height as single-gang plates but almost twice as wide). There are also triple- and quad-gang plates, but they are not used as often as single- and double-gang plates. Figure 1 shows the difference between a single- and double-gang wall plate.

 
Figure 1: Single- and double-gang wall plates

Each manufacturer has different guidelines about how many openings for jacks fit into each type of wall plate. Most manufacturers, however, agree that six jacks are the most you can fit into a single-gang wall plate.

With the advent of technology and applications such as videoconferencing and fiber-to-the-desktop, users need more jacks and different types of cabling brought to the desktop. You can bring Category 3, Category 5e, or Category 6 UTP cable, fiber-optic and coaxial cable all to the desktop for voice, data, and video with 6-, 12- and 16-jack wall plates.

Fixed-Design Wall Plates

A fixed-design wall plate cannot have its jack configuration changed. In this type of wall plate, the jack configuration is determined at the factory, and the jacks are molded as part of the plate assembly.

You must understand a few issues before choosing a particular fixed-design wall plate for your cabling installation, including the following:

• Number of jacks
• Types of jacks
• Labeling

Number of Jacks

Because fixed-design wall plates have their jacks molded into the faceplate assembly, the number of jacks that can fit into the faceplate is limited. It is very unusual to find a fixed-design faceplate with more than two jacks (they are usually in an over-under configuration, with one jack above the other). Most fixed-design wall plates are for UTP or coaxial copper cable only; but fiber-optic fixed-design wall plates are available for fiber-to-the-desk applications. Figure 1 shows some examples of fixed-design wall plates with various numbers and types of sockets.

 
Figure 1: Fixed-design wall plates

Types of Jacks

Fixed-design wall plates can accommodate many different types of jacks for different types of data communications media. However, you cannot change a wall plate's configuration once it is in place; instead, you must install a completely new wall plate with a different configuration.

The most common configuration of a fixed-design wall plate is the single six-position (RJ-11) or eight-position (RJ-45) jack (as shown in Figure 2), which is most often used for home or office telephone connections. This type of wall plate can be found in your local hardware store or home center.

 
Figure 2: Fixed-design plates with a single RJ-11 or RJ-45 jack

Warning

Fixed-design wall plates that have eight-position jacks must be carefully checked to see if they are data-capable. We know of retail outlets that claim their eight-position, fixed-design wall plates are "CAT 5e" compliant. They're not. They use screw terminals instead of 110-type IDC connections. If it's got screws, folks, it ain't Category 5e.

Other types of fixed-design wall plates can include any combination of socket connectors, based on market demand and the whims of the manufacturer. Some of the connector combinations commonly found are as follows:

• Single RJ-11 type
• Single RJ-45 type
• Single coax (TV cable)
• Single BNC
• Dual RJ-11 type
• Dual RJ-45 type
• Single RJ-11 type, single RJ-45 type
• Single RJ-11 type, single coax (TV cable)
• Single RJ-45 type, single BNC

Labeling

Not all wall plate connectors are labeled. Most fixed-design wall plates don't have special preparations for labeling (unlike modular plates). However, that doesn't mean it isn't important to label each connection; on the contrary, it is extremely important so that you can tell which connection is which (vital when troubleshooting). Additionally, some jacks, though they look the same, may serve a completely different purpose. For example, RJ-45 jacks can be used for both PBX telephone and Ethernet networking, so it's helpful to label which is which if a fixed-design plate has two RJ-45 jacks.

For these reasons, structured-cabling manufacturers have come up with different methods of labeling fixed-design wall plates. The most popular method is using adhesive-backed stickers or labels of some kind. There are alphanumeric labels (e.g., LAN and Phone) as well as icon labels with pictures of computers for LAN ports and pictures of telephones for telephone ports. Instead of printed labels, sometimes the manufacturer will mold the labels or icons directly into the wall plate.

Fixed-Design or Modular Plate | Wall Plate Design

Another design and installation decision you have to make is whether to use fixed-design or modular wall plates. Fixed-design wall plates (as shown in Figure 1) are available with multiple kinds of jacks, but the jacks are molded as part of the wall plate. You cannot remove the jack and replace it with a different type of connector.

 
Figure 1: A fixed-design wall plate

Fixed-design plates are usually used in telephone applications rather than LAN wiring applications because, although they are cheap, they have limited flexibility. Fixed-design plates have a couple of advantages and disadvantages (as shown in Table 1).

Modular wall plates, on the other hand, are generic and have multiple jack locations (as shown in Figure 2). In a modular wall plate system, this plate is known as a faceplate (it's not a wall plate until it has its jacks installed). Jacks for each faceplate are purchased separately from the wall plates.

 
Figure 2: Modular wall plates with multiple jack locations

Table 1: Advantages and Disadvantages of Fixed-Design Wall Plates 

Advantages	Disadvantages
Inexpensive	Configuration cannot be changed
Simple to install	Usually not compatible with high-speed networking systems

Tip

When using modular wall plates, make sure to use the jacks designed for that wall plate system. Generally speaking, jacks from different wall plate systems are not interchangeable.