How to Choose the Right RJ45 Connector for Cat6 & Cat6A Ethernet Cable

■Introduction

If you are picking an RJ45 connector based on cable category (Cat5e, Cat6, Cat6A), this article is NOT for you.

This article is for network installers, technicians, and project managers who care about long-term network performance, PoE provisioning, and standards-based cabling.

At ZION COMMUNICATION, we see regular field-termination failures due to incorrect RJ45 connector selection, which have nothing to do with cable quality. This article covers required RJ45 connector specifications for different types of Ethernet cable (twisted pair cable), required mechanical or electrical compatibility, and potential impact of marketing hype.

■Why RJ45 Connector Selection Matters

RJ45 connector is NOT a passive device.

RJ45 is an active termination component that can affect:

• Signal performance (NEXT, Return Loss)

• Power over Ethernet (PoE, PoE++)

• EMC, grounding

• Mechanical lifetime of the installation

In practice, 70–80% of field termination failures are caused by wrong connector selection, not cable performance. RJ45 connector selection is an engineering task, NOT a purchasable item.

■Conductor Type: Solid vs. Stranded

RJ45 connectors are designed for specific conductor constructions.

Using a stranded-rated connector on solid conductors (or vice versa) can lead to:

• Poor IDC contact

• Increased insertion loss

• Intermittent PoE failures

Always match the connector to the conductor type.

■AWG and Insulation Diameter Compatibility

Ethernet category is NOT enough.

Increasingly different Ethernet cables (Cat6, Cat6A) can have differences affecting RJ45 connector selection. These include:

• Conductor AWG (e.g. 23 AWG vs 24 AWG)

• Insulation sheath / outer diameter

• Cables with indoor, outdoor, or CMX ratings

Cat6A, outdoor Ethernet cables require oversized RJ45 connectors due to increased sheath / outer diameter.

■Shielded vs. Unshielded RJ45 Connectors

RJ45 connectors must match the cable shielding structure.

Using a shielded cable with an unshielded connector will:

• Break the grounding path

• Reduce EMI protection

• Increase alien crosstalk risk

For industrial, PoE++, or high-noise environments, shielded connectors are mandatory.

■RJ45 Connector for PoE and PoE++

Heavy duty PoE connectors are NOT standard.

RJ45 connectors for heavy-duty PoE applications rely on characteristics such as:

• Mechanical contact reliability

• Thermal performance

• Gold plating thickness (min ≥ 50 μin)

Low end connectors can cause:

• Thermal issues

• Resistance

• Failure of PoE signaling

■Outdoor and Industrial Ethernet Applications

Outdoor Ethernet cables (PE/CMX, gel-filled) usually have:

• Oversized diameter

• Stiff outer jacket

• Higher mechanical loads

Standard RJ45 connectors may NOT provide:

• Mechanical connection reliability

• Protection against elements / moisture

• Mechanical lifetime

■Common RJ45 Connector Problems

• Using Cat6 RJ45 for Cat6A cabling

• Connecting shielded cables (e.g. Foil) with unshielded connectors

• Disregarding insulation and cable diameter requirements

• Field-termination on DP links

• Using standard connectors with outdoor rated cables

■ZION COMMUNICATION RJ45 Connector Selectivity Guide

ZION COMMUNICATION offers RJ45 connector varieties designed for professional cabling:

• RJ45 for Cat5e / Cat6 UTP cable

• Cat6A STP and S/FTP cable with Foil-Screened connectors

• Outdoor Ethernet/CMX rated Cable with Oversized RJ45

• PoE / PoE++ ready RJ45 Connectors

• RJ45 for tool-less termination and field installation

RJ45 products are compliant with TIA/EIA-568 standards, ISO/IEC 11801 compliant applications, PoE, and PoE++ rated. Ideal for commercial and data center applications.

■When NOT to Use Field-terminated RJ45 Connectors

Field RJ45 termination is not a silver bullet.

Avoid field-termination in:

• Data centers and high speed backbone links/sites

• SLA networks and Mission-critical applications

• Long-term (permanent) links/sites

■Conclusion

RJ45 connector selection is NOT a creative process.

It should NOT be done with assumptions:

• Mechanical compatibility

• Electrical characteristics

• Shielding

• Reliability of installed applications

Choosing the right RJ45 connectors based on evident issues will greatly reduce loss of time and decrease system failure rates.

ZION COMMUNICATION provides professional RJ45 and Ethernet system solutions for international B2B projects.

Contact us for more information

Will is the Copper Cabling Product Manager at Zion Communication, 

specializing in the development and marketing of Ethernet cabling solutions. 

With extensive industry experience, he is dedicated to delivering high-performance 

and reliable cabling products to OEM/ODM clients worldwide.

will@zion-communication.com

+86 -18268007201