How to Terminate a RJ45 Jack

by DoItYourself Staff

As anyone who has worked with data or telephone wiring knows, connecting cable wiring to an RJ45 jack is entirely different from connecting electrical cables. The cable, itself, is different. Tools needed to install it are different, and the low voltage is different from the high voltage of electrical circuits. Circuits connecting to this wiring are much more sensitive and much less likely to cause harmful electrical shock. This means, procedures used for installing these jacks are also different. If you've yet to install your first RJ45 jack, you will find the information below to be helpful.

Things you'll need.

RJ45 Jacks
Screwdriver
Wire stripper
Wire cutters, or scissors
Punch down tools
Circuit tester

Step 1 – Taking Safety Precautions

Although you are not likely to receive any injury-producing electrical shock from working on cable connected to computers, data switches or servers, circuit shorting can damage sensitive circuits that may be connected to related wiring. Therefor, where possible, cables or wiring you will be working on should be disconnected or unplugged from any electronic device before you begin connecting the wiring.

Step 2 - Choosing Your Terminal Type

Take care in choosing the right terminal type. These terminals are designed differently in different jacks, depending on the type of tool you'll be using to connect wires to these terminals. Some are the screw type terminals onto which you will need a screwdriver to attach the wires. Other terminal types are the slotted type for which you will need an impack punchdown tool with a 110 type blade. Choose your jack based on the terminals it provides, and on the type of tool you'll be using to connect your cable wires. If you buy jacks that have slotted terminals, and if you have no impact punchdown tool to connect them, you'll need to either buy an expensive tool you may never use again, or make another trip to replace your jacks.

Step 3 – Mounting your jack

For clean smooth surfaces on which you plan to leave your jack permanently attached, use the self-bonding, two-sided adhesive piece you will find packed with your jack. If your surface is rough or greasy, or if you think you will likely be moving or removing the jack, use drywall screws or wood screws to attach the jack to the surface.

Step 4 – Connecting Wires to Terminals

Remove about 2 inches of the cable sheathing with the help of a cable stripper. Unwind the four wire pairs you'll find inside the cable. You'll need these wires to be separated into individual wires in order to attach them to the appropriate terminals. Use your wire stripper to remove no more than 3/8 inch of insulation from the individual wires. Refer to the information piece you'll find with the jack. Instruction from this chart will guide you in matching the correct wire color with the correct terminal. Then, terminate these wires on the appropriate terminals, using your screwdriver or punchdown tool. Be sure to leave no more than ½ inch of bare wire between the terminal and the insulated part of the wire.