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Different ferrules for different conductor cross-sections

Ferrules are used in process-reliable conductor assembly, wiring, and further processing. They have many advantages in electromechanical systems in both mechanical and electrical terms. The main task of the ferrule is to prevent the conductor from splicing and to protect the individual litz wires from mechanical effects, such as when connecting to screw terminal blocks. When using spring-cage terminals, a fixed connection between the copper conductor and the ferrule is also of essential importance. Alongside the appropriate ferrule pliers, the material quality of the sleeve is critical for an optimal and, therefore, reliable crimp connection.

The key advantages of ferrules:

  • Increased, long-term operational safety and contact reliability
  • Time-saving further processing (particularly in the case of Push-in terminal blocks)
  • Reliable connection, even with repeated rewiring
  • Reduction in cable breakages
  • Easy cross section detection
  • Increased vibration resistance
  • Permanently low contact resistance
  • Individual litz wires are protected (particularly in the case of screw terminal blocks)
  • Consistent clamping in the case of screw connections

Standards for ferrules

In DIN 46228, the ferrule is defined as being between 0.5 and 50 mm². This standard has four parts:

  • Part 1: Tubular end-sleeves without plastic sleeve
  • Part 2: Crimp-type end-splices, with and without insulation grip
  • Part 3: Conductor-embracing end-splices, without insulation grip
  • Part 4: Tubular end-sleeves with plastic sleeve

Alongside the geometric dimensions of the sleeve, the material, the cross section-dependent color, and the test specifications are all part of the standard. In addition, there is the requirement that the ferrules accommodate Class 2, 5, and 6 conductors. The conductor cross-sections are defined through the electrical resistance values and not, as is the case for the ferrules, through the geometric dimensions. Greater variations in the cross sections are therefore possible (also refer to the section on conductors and cables). Due to this fact, there is a certain discrepancy between the ferrule and the conductor. Ferrule pliers from Phoenix Contact are, however, designed in the main to compensate for these capacity differences. 

In addition to DIN, there is a French standard for the sleeves, NF C 63-023. With the exception of the coloring for some cross sections (see matrix), the NF standard is based on the DIN standard. The UL 486F and the Canadian C22.2 NO. 291-14 are new in the field of standardization for ferrules. These harmonized standards likewise are based on the DIN, but go further into detail on the test methodology and the specific requirements (see the pull-out values table, among other things).

In UL 486F, the special sleeves such as “TWIN” ferrules for a 2-conductor connection are also normatively defined for the first time. For certification in accordance with the aforementioned UL and CSA standards, comprehensive testing must be carried out by the respective organization. Not just the ferrules are tested and certified, but also the entire system, consisting of ferrule pliers and ferrule.

Trailblazer for international standards on quality, safety, and compatibility

As one of the first manufacturers, Phoenix Contact had ferrules combined with a selection of ferrule pliers certified in accordance with the UL 486F standard that went into force in 2016. Together with conformity with the DIN 46228‑1/‑4 standard, the ferrule pliers meet the market requirements in terms of quality, safety, and compatibility. Thus Phoenix Contact also has a system with global acceptance for its export-oriented customers in its range of offerings.

High-quality material – Made in Germany

As a manufacturer and systems supplier in the field of connection technology, our range of products consists of high-quality ferrules – made in Germany – and crimping tools designed to work with them for reliable processing.

Crimp professionally – with mechanical crimping tools, you can press all types of contacts safely and without trouble

Crimp all types of contacts – ferrules, cable lugs, coaxial connectors, or crimp contacts – professionally and safely. An optimized leverage and ergonomic gripping geometries support low-fatigue crimps with the crimping tools from Phoenix Contact. A special force transmission principle reduces the actuation forces needed by up to 30%. The integrated pressure lock ensures long-term stable, high-quality, gas-tight quality crimping.

  • Simple and convenient handling thanks to ergonomic grip shapes
  • Durable due to the use of high-quality components and raw materials
  • Process-safe thanks to the integrated pressure lock
  • Optimized leverage supports low-fatigue use


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