Data Jack Wiring
Wiring an Ethernet data jack is straightforward when the cable pairs are kept organized and the same wiring standard is used at both ends. This guide explains how to prepare the cable, arrange the conductors and punch them into a standard RJ45-style data jack.
Strip the Outer Cable Jacket
Carefully remove approximately 1½ to 2 inches of the outer cable jacket to expose the four twisted wire pairs inside.
Be careful not to cut or nick the insulation on the individual conductors. A damaged wire can cause an unreliable network connection or prevent the connection from working at all.
Separate the Four Twisted Pairs
Gently separate the four wire pairs so that each pair can be routed to the correct terminal on the data jack.
Standard Ethernet cable typically contains:
- Blue and White/Blue
- Orange and White/Orange
- Green and White/Green
- Brown and White/Brown
Choose T568A or T568B
Most Ethernet jacks include color-coded markings for both the T568A and T568B wiring standards. Either standard can work, but the same standard should be used at both ends of the cable.
T568A vs. T568B
The main difference between the two standards is the position of the orange and green wire pairs.
| Pin | T568A | T568B |
|---|---|---|
| 1 | White/Green | White/Orange |
| 2 | Green | Orange |
| 3 | White/Orange | White/Green |
| 4 | Blue | Blue |
| 5 | White/Blue | White/Blue |
| 6 | Orange | Green |
| 7 | White/Brown | White/Brown |
| 8 | Brown | Brown |
Place the Wires in the Correct Terminals
Following the T568A or T568B color guide printed on the jack, lay each conductor into its corresponding terminal channel.
Keep the wire pairs twisted as close to the terminal as possible and avoid crossing the conductors unnecessarily.
Punch Down and Secure the Wires
Press each conductor firmly into the V-shaped insulation displacement contacts on the jack using the appropriate punch-down tool.
The contact blades pierce the insulation and make an electrical connection with the copper conductor. Make sure each wire is fully seated before securing the jack's retaining covers.
Test the Data Jack
After both ends of the cable are terminated, test the connection with an Ethernet cable tester whenever possible.
A tester can confirm that all eight conductors are connected in the proper order and help identify open, crossed or miswired connections.
If the Connection Doesn't Work
Check that the same wiring standard was used on both ends of the cable and verify that every conductor is completely seated in its terminal.
Also inspect the cable for damaged conductors and confirm that the network equipment and patch cables are working correctly.
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