TopTechnical DictionaryRJ45 connector

RJ45 connector

The most popular RJ45 connector is an 8P8C (8 Position 8 Contact) connector with 8 positions and 8 physical contacts. For comparison, 8P4C connector looks almost identical, however, it has only 4 physical contacts.


Fig. 1. Example RJ45 connectors


Fig. 2. GEMINI-62BB-13P IP camera with RJ45 port


Delta offer includes cables that are factory terminated with RJ45 connectors also referred to as patch cords available in different lengths and categories. Modular connectors are also available (Fig. 3) for manual crimping with a HT-546 crimping tool (Fig. 4), and modular HAND type connectors for crimping without tools (Fig. 5).


Fig. 3. RJ45 modular connector


Fig. 4. Crimping tool HT-546


Fig. 5. Modular RJ45-HAND connector


Terminating the network cable with RJ45 is not difficult, however, as for any other connectors, correct crimping requires high precision and accuracy. T568B or T568A standard requirements must be observed. The standards define the order of the network cable conductors in RJ45 connectors depending its application: a simple cable for connecting network devices (routers, switches, IP cameras) or a cross cable for direct connection of two PCs with network adapters.


Take precautions when stripping the sheath to prevent damage to the conductors and to cut the conductors to the same length, i.e. all conductor must reach the end of the tunnel inside the connector. Make sure the sheath is inside the connector. Otherwise, the conductors may be accidentally disconnected after a while, which makes the problem difficult to identify and eliminate. The diagrams show correctly and incorrectly crimped terminals (Fig. 6).


Fig. 6.


1 - Correctly crimped RJ45 connector

2 - Incorrectly crimped RJ45 connector (sheath does not reach the modular connector and the conductor insulator is damaged).

Like the twisted pair, modular connectors are also available in different types and categories. The connector is selected depending on the network cable used: shielded FTP or standard UTP (Fig. 7). Delta offers modular RJ45 connectors with each conductor attached with three crimp tabs for better contact with the conductor and improved durability of the connector.


Fig. 7.


1 - RJ45 modular connector on FTP Cat. 5 cable

2 - RJ45 modular connector on UTP Cat. 6 cable

3 - RJ45 modular connector on UTP Cat. 5 cable

4 - RJ45 modular connector on UTP Cat. 5e cable with a 3-tab crimp terminal

Modular RJ45 connector can be fitted with colour boots (Fig. 8). The boots should be put on the cable before crimping, otherwise, it will not be possible due to the boot design.


Fig. 8. Colour boots: outer and inner.


Wiring sequence inside the RJ-45 plug 


1 - brown
2 - white/brown
3 - orange
4 - white/blue
5 - blue
6 - white/orange
7 - green
8 - white/green


1 - brown
2 - white/brown
3 - green
4 - white/blue
5 - blue
6 - white/green
7 - orange
8 - white/orange


Line - pair of wires