Everything You Need To Know About Ferrule

Stranded cables must be inserted into screw terminals or spring connectors in domestic and industrial wiring. To automate a task on industrial equipment, hundreds, if not thousands, of these connections may be necessary. If even one of these cables becomes loose or breaks, you’re going to experience some costly downtime.

As a result, each link is crucial. While the flexibility of stranded wire makes routing far easier than solid-core wire, the ends of the wire tend to splay apart. It’s a bit of a gamble to connect to a screw or spring connector. The wire would be stranded in the center and solid on the ends in an ideal world.

Does this seem like an impossible task? With ferrule connectors, it is possible and straightforward to accomplish.

Table of Contents

What Is A Ferrule?

A ferrule is a tiny metal collar used to crimp and gather wires at termination or junction in wiring. These components are used to make a variety of electrical components, such as circuit boards, and they can also be utilized in various wiring tasks. Electrical component suppliers frequently provide a variety of ferrules in different sizes and styles for multiple projects. Customers may also be able to request custom products for specific products, albeit some manufacturers may require a larger order.

In other circumstances, the ferrule takes the shape of a short wire tube with a flared base. An electrician or technician slides it over the wires in question and crimps it together, fastening them together. This can be done with a crimping tool or the technician’s heavy pliers or clamps. Depending on the setup, the technician can place the ferrule’s end into a contact point to connect wiring, or the ferrule can produce a wire or lead terminal.

Rubber, plastic, and other materials are used to insulate ferrules. These might be color-coded for ease of use. Color coding can be used by operators to aid in the appropriate connection of contacts or various code types of wires. The insulation could be in the shape of a removable band, allowing the user to choose the color that best suits the application. Ferrules that aren’t insulated are left exposed.

Ferrules yoked together in bandoliers that may be fed into manufacturing equipment are available for purchase for automation reasons. As the wiring passes down the assembly line, the machine creates the connections, automatically clamping them. A technician may inspect the links for wear or faulty crimping, but they do not conduct the task by hand. Many electrical components can be manufactured faster with automation.

Ferrules are especially handy for connecting wires to larger circuits and gadgets. While the cables can be brought into immediate touch, they are vulnerable to breakage and strain. The ferrule creates a protective coating that reduces stress at the wire point, reducing the likelihood of future system problems. In the case of a draw or strain from the other end, the wire is not forced to bend or twist in a way that could predispose it to crack and failure.

Wire Ferrule Color Coding

Depending on the wire you need to crimp, ferrules come in several sizes, with color codes on the shoulder section indicating the size. One potential difficulty is that at least three different ferrule color codes might confuse if different varieties are mixed. Ferrules should be kept in their original container until they’re needed.

What Is A Ferrule Crimper?

A ferrule crimper is a hand-held tool used to attach a ferrule to stranded or solid wire. After the stripped wire has been introduced, the crimper tool crushes the ferrule sleeve. Ferrules are one of several various types of terminals available. On the other hand, Ferrules are unique in that most other terminals may be fitted with a single type of crimping tool.

A ferrule crimper tool is helpful, but it won’t help you install a regular spade terminal; you’ll need a different type of crimping tool. The ferrule crimper is only compatible with ferrule terminals and cannot be used with other profile terminals.

How to Use A Ferrule Crimper Tool?

It’s simple to use a ferrule crimper tool. But, like with any endeavor, it necessitates some preparation; get it right, and the crimping job will move like butter. The American Wire Gauge (AWG) standard is used to gauge wire. The larger the wire, the lower the number.

The size of the wire we’re working with is essential since it determines the size of ferrule termination we’ll utilize. This isn’t a problem if you have a variety of ferrules on hand; you can do a Cinderella test with them. Be sure the ferrule gauge matches the wiring gauge if you’re ordering ferrules.

What Does a Ferrule Do?

The bundle is crimped into what looks like the termination of a solid-core wire. The ferrule has several advantages, including strain reduction and inserting every wire strand into a connection without worrying about a few being pushed to the sides. Because there is no air gap between the wire and the connector, ferrules considerably minimize contact resistance and even reduce oxidation in the strands.

Types of Ferrules

Ferrules come in a variety of shapes and sizes on the electrical market. Ferrules can be utilized in a variety of ways. Almost every electrician has heard of them. However, they are all aware that ferrules come in various shapes and sizes and serve multiple functions.

Wire ferrules are a type of pin termination that prevents the stranded wire from unraveling and improves the stability of electrical connections. While facilitating wire insertion into the terminal clamp guarantees solid electrical connections and prevents conductor breakage due to bending, wire tension, or vibration.

To attach a ferrule, you must first strip it. Then, attach it to the cable end using a specific crimping tool. A ferrule is a simplistic device with a simple design. The metal portion, which is tin-coated, is made of copper.

Its diameters should also be considered. Its cross-section is usually matched to the cable to which it will be connected. A 2.5 ferrule, for example, indicates that it will be linked to a 2.5mm2 cable.

Insulated Ferrule

A plastic-colored sleeve covers the tin-plated copper tube in an insulated wire ferrule. It facilitates wire size identification and quality inspection by allowing for wire size’s visible color designation. Insulated wire ferrules are more convenient to use, particularly on smaller conductors. It can be utilized in various applications and provides a secure connection.

Uninsulated Ferrules

Without the plastic shoulder, ferrules are available. When termination space is limited, or a shoulder obstructs an adjacent terminal, the non-shouldered or uninsulated versions are preferred. Factory-made wire in 13A plugs and flying leads on UK-style RCBOs frequently have uninsulated shoulders.

Insulated ferrules are easier to work with, particularly on smaller conductors, because the shoulder assists in guiding wire strands to the ferrule pin. Uninsulated ferrules without a shoulder can be difficult to thread.

Single Ferrule

One cable can be crimped to a single ferrule. It comes in two varieties: insulated and uninsulated.

Twin-Wire Ferrules

When two conductors must be wired into a single terminal, such as generating a standard supply for push-button switches in industrial panels, twin, dual, or double wire ferrules come in handy. They help connect several terminals within heating or lighting controls in a domestic setup. There are two types of twin ferrules: insulated and uninsulated. Two conductors, including insulation, are accommodated by an oval-shaped shoulder on insulated versions.

Twin ferrules are color-coded in the same way that single insulated ferrules are—a twin 2.5mm2 in the German (W) system has a blue shoulder. The barrel has a 5.0mm2 cross-sectional area, which is double that of the standard barrel (2 x 2.5mm2)

To accommodate the location of an electrical terminal, ferrules come in a variety of pin lengths. Reaching recessed PCB terminals within an electrical enclosure requires a longer ferrule pin. Alternatively, they’re matched to the exact size of control or switchgear terminals. Ferrules with 8, 10, 12, or 18mm pins are offered in 2.5mm2 insulated ferrules.

What Makes A Wire Ferrule Different from A Terminal?

Compared to termination, a wire ferrule usually has a different crimping location; rather than covering the barrel with insulation, a wire ferrule is crimped in the metal tube itself. A wire ferrule is crimped into a metal tube that does not extend into the insulation. Both a wire ferrule and a wire terminal clearly show this distinction.

What Are Some of The Benefits of Employing A Wire Ferrule?

Wire ferrules can be found in various sectors that require power distribution and connections. They’re extremely popular in automotive and industrial settings, and they’re usually utilized with screw terminal blocks. A wire ferrule has advantages over just inserting bare wire strands. The ferrule is no stranger to connections, boasting features such as no strand fraying, improved contact, simpler repeated insertion and removal from a terminal, and strain relief. Many people who utilize wire ferrules appreciate the convenience of frequent insertion and removal for long-term tasks.

How Do I Choose A High-Quality Ferrule?

Different ferrule producers employ other processes for making ferrules, but annealing is critical in generating a high-quality ferrule. It occurs when metal is heated and then allowed to cool gradually. This procedure modifies the physical and chemical processes to boost the material’s flexibility and toughness. The annealing process has three stages: recovery, recrystallization, and grain growth.

The ferrule gets weaker when the annealing procedure is missed, and it is more prone to break when crimped onto a wire or when the wire is moved or handled in the cabinet in the future. The procedure of annealing is used to create ferrules. As in other circumstances, different processes imply additional costs and, as a result, higher pricing for the end-user. Many low-cost producers forgo the annealing process, resulting in excessively rigid ferrules that are susceptible to cracking.

Advantages of Ferrules

Ferrules provide mechanical benefits during wiring by minimizing splaying and overbending of individual Litz wire ends and protecting against damage. This is especially useful when executing repeated rewiring operations in the control cabinet, not for safety. The conductor and sleeve are permanently and irreversibly linked by the crimping process, which bundles all of the individual Litz wires.

Individual Litz wires are frequently not connected cleanly in perplexing installation conditions, affecting air clearances, creepage distances, and even spark-overs. Ferrules with plastic collars benefit from having the conductor insulation entirely immersed and overlapped in the sleeve body, giving bend protection. The color of the plastic collar indicates the cross-section range.

Ferrules are also advantageous from an electrical standpoint. On the market, standard ferrules are constructed of highly conductive copper materials. Tin is generally applied on the surface to prevent corrosion. The friction-locked and form-fit crimped ferrule is a transition point in the current flow and should be avoided from an electro-technical standpoint. After all, every transition point implies resistance to contact.

Last but Not Least, Are Ferrules Necessary?

Significant novel connection technologies are currently available on the market for industrial electrical connection technology, providing consumers numerous benefits. Many users, however, are still perplexed by a minor point: is a ferrule appropriate or even necessary for conductor connections?

In the 1960s, ferrules were developed. They were initially designed to provide mechanical protection for the copper wire in the terminal connection. The terminal screw would frequently directly touch the conductor, causing damage or possibly an open circuit. The sleeve provides mechanical protection here. The Litz wire ends might also be soldered, but tin-lead solder becomes exceedingly viscous when subjected to pressure and temperature changes. This frequently resulted in contact issues, and standards eventually restricted the use of this method.

Pre-assembled Litz wire ends are still widely employed in recent revolutionary connection technologies. This is because ferrules still have some advantages. Furthermore, the conductor pre-treatment process — cutting to length, stripping, and crimping – has a lot of room for improvement and cost savings.