Cat5 Wiring Diagram & Cat 5 Cable Installation

Jan 9th 2019

Cat5 Wiring Diagram & Cat 5 Cable Installation

Pre-cut Cat5 cable kits don't always fit your needs and they're significantly more expensive than buying a spool and installing the connectors yourself. Making your own Cat5 cables is far easier than you may think and all you need are a few things.

Equipment List

  • Cat5 cable spool (500' or 1000')
  • RJ45 connectors
  • Cable stripper
  • RJ45 crimper
  • Cat5 cable diagram

Cat5 Wire Diagrams

There are two types of Cat5 cable you'll need to learn about when it comes to wiring, straight Cat5 and cross over Cat5. They're mostly the same except for four wires per cable and the diagrams below demonstrates this difference as well as how to wire them.

Cat5 Straight Diagram

This diagram is used for "straight through" cables, also called patch cables, and they're the standard Ethernet cable used when you're connecting a device to a router, switch, or hub. The reason why the green cable is separated by the blue set is that it allows for longer cable runs up to ~100m. If you need to use a longer run, you'll have to add a  PoE extender or video balun to your cable run depending on your application.

This diagram shows the wiring sequence for EAI standard Ethernet cable (TIA-568B).

Cat 5 Cross Over Diagram

Cross over cable is used when you want to connect two computers directly to one another without the use of a router, network switch, or hub. This is rarely done these days because of switches and how convenient they are when it comes to network management. 

This diagram shows the wiring sequence for EAI cross over Ethernet cable (TIA-568A).

Installing Connectors on a Cat5 Cable

1. Strip off the cable sheath from the Cat5 cable using a cable stripper. You can cut anywhere between 1/3" to 1" of the sleeve off. The more comfortable you are, the less you need to remove. (1/2" to 3/4" seems to be the sweet spot.)

2. Group the different wires together by color, i.e. green & green stripe, orange & orange strip, etc.

3. Sort the wires according to the Cat5 cable diagrams above and grip firmly between your index finger & thumb.

4. Measure 1/2" from the cable sheath and cut straight across the wires with a wire cutter (scissors if you're desperate).

5. Gently insert the wires into the RJ45 connector with the orange & white stripe wire taking the 1 position pointed out in the diagrams above.

6. Make sure that there are no short wires and that the cable jacket is beneath the locking tab at the base of the RJ45 connector

7. Use the RJ45 crimper to compress the locking tab into the Cat5 cable sleeve for a tight fit. The copper tabs at the end of the connector will pierce the wires inside.

8. Repeat on the other end of your cable for straight through cable. If you're using a cross-over cable, use that configuration from the diagram above.