Q&A With HELU: Ferrules

October 28, 2022

A popular trend that is growing in the US market is the use of ferrules, also known as end sleeves, to terminate single and multi-conductor wires, e.g. in the terminal blocks within a machine’s control panel. For US equipment manufacturers that export to Europe, using ferrules is a requirement toreceive CE certification so that a company can do business within the European Union. Regional Sales Manager Bob Wells takes some time to answer a few questions he hears in the field about this cable termination technique.

Q: What is a wire ferrule?

A: A wire ferrule is a type of pin terminal used to prevent the unraveling of stranded wire and to increase the stability of electrical connections. It is usually made out of tin plated copper. This tube or barrel is placed over a section of stranded wire extending from stripped insulation,then compressed with a crimping tool to hold the strands together.

Q: What are some advantages of using ferrules compared to terminating stranded conductors?

A: Using ferrules enables users to take advantage of the features of stranded wire without the problems caused by a bare wire connection. Every strand of a wire can now be inserted into a connector, without any strands fanning out to the sides upon insertion. The seconds required to apply a ferrule to the wire ends are more than made up by the ease of insertion. Once crimped, the bundle is converted into what acts as the end of a solid conductor wire. Ferrules greatly reduce the contact resistance between the wire and connector and minimize oxidation in the strands because of the limited air space between them. Finally, ferrules provide strain relief which prevents conductor breakage due to bending and vibration.

Q. What are some of the types of ferrules available in the market?

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A: There are three different types of wire ferrules: insulated, non-insulated and twin/dual/double.

A) Insulated ferrules have a plastic-colored PVC collar or shoulder over the tin plated copper barrel. These ferrules are easier to work with, especially on smaller conductors, where the shoulder helps to guide the individual wire strands into position.
B) Non-insulated ferrules do not have a shoulder. Without the shoulder, it can be difficult to install because the shoulder is not there to guide the conductor strands as it’s very similar to threading a needle. However, when space is limited, non-insulated ferrules are popular.
C) Twin/dual/double wire ferrules have a larger insulated collar that allows you to insert two wires of the same size into the ferrule tube to be crimped tightly and securely using a properly sized ferrule. This provides an efficient connection of multiple wires in the same terminal clamp or simplifies wire jumping between terminal clamps.

Q: What size ferrule should be used?

A: The selected ferrule should match the cross section of the wire being used. For example, a 1.5 mm² (AWG 16) ferrule means it will be connected to a 1.5 mm² (AWG 16) wire. If a double ferrule is used installers need to be careful as two AWG conductors may need a larger ferrule compared to using two metric-sized conductors. If two AWG wires of the same size are being used, then the correct ferrule size is determined by increasing the total wire size by three steps. For example, two AWG 20 wires, which each have a cross sectional area of 0.519 mm² each, are equivalent to a single AWG 17 (1.04 mm²), so a 1.5 mm² (AWG 16) capacity ferrule should be specified. While it’s theoretically possible for two AWG 20 wires to fit into a 1.0 mm² capacity ferrule, it is likely to be a tight fit and more challenging if one wants to efficiently terminate the wires.

Q: Why do insulated ferrules have different color shoulders?

A: The shoulder color on insulated ferrules identifies the matching conductor size. There are three different standards as shown below. The colors used can be the user’s choice unless specified. However, blue for AWG 14, black for AWG 16, and red for AWG 18 are typically the color/size used in the US market.

Q: Why are there different lengths of ferrules?

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A: Different types of connectors require different ferrule lengths, i.e. barrel length, which can range from 0.24-1.26 in (6-32 mm) depending on the ferrule size. As an example, a recessed PCB terminal may require a longer barrel to properly terminate, whereas a DIN rail terminal block in a control panel may just require a standard-length barrel, which is typically 0.5 inches (12 mm).

Special hand tools to properly strip wires to the correct length and depth so as to avoid breaking conductor strands, and to crimp the ferrule with the correct pressure to ensure a secure fit on the wire without damaging the ferrule or wire are available from most ferrule suppliers.

Q: Is there a special tool required to properly install ferrules?

A: Yes, there are specialized tools one should use to properly cut, strip and crimp the ferrules to ensure proper contact with the wire. You do not want to use pliers as this will not provide a uniform crimp around the wire. Based on where the cable or wire is being terminated, either at an assembly/harness shop or on-site, there are a variety of handheld and electric bench-top machines to process the cable and wires quickly and efficiently.

Source

Put to the Ultimate Test – Part 1: Torsion Tests by HELUKABEL

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Cables and wires in industrial robots and other moving machine parts are often required to withstand extreme stresses caused by torsion. Constant repetitive movements put materials under considerable strain. At the same time, operators expect components to function perfectly and reliably throughout their entire service life to avoid disruptions, outages and safety hazards.

For this reason, at HELUKABEL, we simulate intensive and continuous torsion stresses under realistic conditions with our high-tech testing equipment in Windsbach. We have several types of apparatus for doing this because some of our customers, for example those in the automotive industry, have very precise specifications for how a torsion test is carried out. The tests show that our cables and wires withstand speeds up to 1,000°/s, accelerations up to 2,000°/s² and torsion angles up to 720°. Hence, we make sure that each product always meets our customers’ high standards, and that they receive the impeccable quality they rightly expect from us as a leading supplier of cables, wires and accessories for more than 40 years.

What Is Torsion?

To learn the answer, click here

30 Minute Live Webinar 2:30 PM ET January 19th, 2023

With PC-based automation, you can implement applications and solutions that far exceed the functions of a classic controller. SIMATIC PC-based products offer you a flexible, innovative platform with long-term availability that give you a home field advantage when meeting the challenges of the digital factory for your machines and plants.

Festo Didactic at the Forefront of Developing Canada’s Future Work Force

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With Canadian manufacturing suffering from a growing labour shortage, the participation of industry in skills development is emerging as a vital component in hiring and retention.

The needs are stark: The Canadian Exporters and Manufacturers Association says almost 40% of its members have jobs they can’t fill. Five years from now, 60% expect to be short-staffed, especially when it comes to skilled trades. Statistics Canada forecasts the country’s labour force growth rate will remain below 0.2% for the rest of the decade, below replacement levels.

This growing shortage is affecting companies of all sizes. Already, some manufacturers acknowledge losing out on contracts because they can’t find the manpower to fulfill them.

In reality, the challenge is two-fold: to replenish and expand the workforce to help close the gap between the number of job seekers and vacancies through 2030 when the last baby boomers reach age 65, and ensure workers get opportunities throughout their careers to upgrade or add to their skillset as current technologies evolve and new ones emerge. Festo, through Festo Didactic, one of the world leading provider of equipment and solutions for technical education, intends to help Canada meet this challenge on both fronts. In essence, the approach Festo has always taken is that the learning never stops.

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