Press for terminals of wires: professional choice and technique of work

Poor contact in the electric circuit of a car or stationary wiring often becomes a direct consequence of the use of inappropriate wire-stamp or a violation of the crimping technology. A weak compound leads to local overheating, copper oxidation and, in the worst case, to the insulation ignition under load. A properly selected tool provides the necessary deformation of the metal, creating a monolithic compound with minimal transient resistance.

The modern market offers many solutions, from simple hand mites to complex hydraulic systems, each of which has its own application area. The choice of a particular device depends on the cross section of the treated veins, the type of tips and the frequency of work. Mistaking a matrix or tool type can cost more than buying quality equipment, especially when it comes to high-voltage systems or starter circuits.

In this article, we will discuss in detail the classification of tools, the criteria for selecting matrices and the step-by-step algorithm for performing works that will exclude marriage. Understanding the physical processes of metal compression will help you avoid common mistakes and ensure the longevity of electrical connections in all operating conditions.

Classification of tools for pressurization

All devices for forming reliable contact are divided into several main categories depending on the source of force and the design of the mechanism. Hand mites. They are the most common option for household use and rare garage repairs. They are compact, do not require maintenance and allow you to work in hard-to-reach places where bulky equipment simply does not fit.

For large volumes of work or work with thick veins are used hydraulic pressesThey can be hand-held (with a separate pump) or battery-powered. Battery models such as Greenlee or RidgidThey allow you to perform hundreds of pressings on a single charge, significantly speeding up the installation process of large switchboards or cable tracks.

• 🛠️ Mechanical mites with fixed sponges - for monolithic veins of small section.
• ⚙️ The tool with rotary matrices is a universal solution for different types of tips.
• 💧 Hydraulic heads – provide maximum force for large diameter cables.

It is important to note that professional tool Often equipped with an unlocking mechanism that prevents the sponge from being unclothed until the full compression cycle is complete. This eliminates the possibility of undepression, which is the main cause of defective compounds. The use of simple pliers instead of specialized press is unacceptable when working with power lines.

Types of matrices and their correspondence to terminals

The key element of any press is a matrix, the profile of which must accurately match the geometry of the compressed tip. There are matrices for sleeves, ring terminals, pin tips and multicore joints. Incorrect choice of shape leads either to damage to the insulating cuff, or to insufficient compression of the conductive part.

Matrixes can be built into the tool body or removable. Replaceable sets allow you to use one press to work with different sizes, which saves budget and space in the toolbox. When choosing, pay attention to the marking, which is usually applied directly to the working part or handle.

The following table of correspondence of matrices types and their application areas is given:

Type of matrix	Compression form	Application	vein material
Oval (D-shaped)	From both sides.	Fills, NSHVI tips	Copper, aluminum
Hexagonal	Circular	Power cables, GML shells	Copper.
U-shaped	Three sides.	Aluminum tips	aluminum
trapezoid	Flat.	Autosound terminals	Copper, Lunched Copper.

When working with non-ferrous metals, the compatibility of materials must be strictly observed. For example, aluminum often requires matrices with a wider compression profile to avoid breaking the veins when deformed. The use of copper matrices for aluminum wires can lead to the formation of cracks in the metal.

The technology of proper crimping

The process of creating a reliable connection requires a sequence of actions, neglect of which negates even the use of an expensive tool. First, it is necessary to clean the insulation for a length corresponding to the depth of the tip landing, without damaging the individual wires of the vein. Any damage to the conductor becomes a focus of voltage concentration.

Then a shrink tube is put on the wire (if it is not part of the terminal), and the vein is inserted into the tailing tip to the end. It is important that all the wires are inside the sleeve, and the insulation does not fall into the clamp area. After that, the tool is positioned so that the matrix covers the metal part of the terminal.

Then compression is made until a characteristic click or close of the handles. If multiposition crimping is used, the first operation is performed closer to the edge of the tip, and the subsequent ones are shifted towards the screw hole with a slight overlap of the previous compression site. This ensures a uniform distribution of pressure throughout the metal.

After the completion of the mechanical part, it is necessary to check the quality of the connection by light mechanical action. The tip should not be turned on the vein or removed by the effort of the hands. Only after a successful check can you sit the thermal insulation and install the terminal in a regular place.

Features of working with aluminum wires

Working with aluminum requires a special approach due to the tendency of this metal to rapid oxidation and fluidity under load. Aluminum tips often have quartz-vaseline lubricant inside, which prevents oxygen from accessing the metal. When cleaning such a wire, it is important not to remove the factory lubricant completely, but only to refresh the contact.

For aluminum, it is critical to use matrices that create sufficient pressure, but do not break the metal. Excessive force can lead to thinning of the walls of the sleeve and a decrease in its mechanical strength. In addition, aluminum is subject to galvanic corrosion when in contact with copper, so the transitional connections must be made through bimetallic sleeves or using special pastes.

⚠️ Attention: It is strictly forbidden to use for squeezing aluminum wires matrix designed exclusively for copper, without checking the compatibility of profiles. This can lead to the destruction of the connection during operation.

Also, the temperature expansion of aluminum, which is higher than that of copper, should be taken into account. This requires periodic lifting of contact connections in the first months of operation, if the design of the device allows it. In automotive wiring, aluminum is less common, but in commercial transport and special equipment, its use is common.

Secrets of Long Service Contacts

To extend the service life of the connections in vibration conditions (cars, motor vehicles) it is recommended to additionally fix the contact place with a seal or plastic clamping after squeezing and shrinkage of thermal insulation. This will reduce the amplitude of the wire oscillations at the terminal entrance, preventing the vein from breaking from metal fatigue.

Common errors and their consequences

One of the most common mistakes is the use of universal “folk” methods, when a hammer and chisel are used instead of a press or ordinary pliers. Such flattening does not create uniform pressure on all sides, leaving a void inside, where sparking and heating will begin over time. Transition resistance In this relationship, it will grow constantly.

Another mistake is choosing a tip with a larger internal diameter than the wire cross section. In an attempt to compensate for the gap, the masters often stuff free space with wire clippings (chukami). This is a gross violation of the technology, as the added pieces do not have electrical contact with the main living room and create points of local overheating.

• 🔥 Overheating of contact due to underweight or oxidation.
• ⚡ Sparkling and the possibility of short circuit.
• 📉 Voltage drop in the on-board network of the car.

Another nuance is ignoring the insulating cuff on the terminal. If the mites do not have a limiter, you can accidentally damage the insulation of the wire at the very entrance to the sleeve. In places of folds and vibrations, this will lead to a rapid break of the vein. Always monitor the position of the tool relative to the edge of the insulation.

Tool care and storage

So terminal-press It has been a long service and ensures stable quality of work, it must be properly taken care of. After each shift, it is recommended to wipe the working surfaces of the matrices with rags, removing metal dust and residues of insulation. The accumulation of dirt can change the geometry of compression and lead to marriage.

The moving parts of mechanical mites periodically require lubrication with light engine oil. For hydraulic tools, it is important to monitor the level of oil and the absence of leaks in the seals. Store the tool in a dry place, preferably in the factory case, to exclude moisture and mechanical damage during transportation.

Regularly check the condition of the sponges for chips and deformities. Even a microscopic defect on the surface of the matrix can leave burrs on the terminal, which can damage the insulation of neighboring wires in the tourniquet. Timely replacement of worn matrices will be cheaper than repairing burnt wiring.

⚠️ Warning: Never use a damaged tool with cracked handles or deformed hinges. At the time of maximum effort, such a tool can rupture, which will lead to serious injuries to the hands.

Frequently Asked Questions (FAQ)

Can you squeeze copper tips with aluminum matrices?

Use of aluminum matrices for copper is not recommended, as the compression profile may not provide the desired contact density for a harder copper alloy. However, copper matrices are sometimes used for aluminum with caution. It is best to follow the recommendations of the manufacturer of tips.

Do I need to squirt the wire before squeezing?

In modern standards, tinting is veined before squeezing into a sleeve or tip. forbidden. The solder is a soft metal, and under pressure it will “float”, the contact will weaken, which will lead to heating. You only need to squeeze a clean, twisted vein.

How do you know if the scoring is done well?

Qualitative crimping is characterized by the absence of gaps between the sleeve and the wire, a symmetrical form of flattening and the inability to pull the wire by the effort of the hands. Visually, there should be no cracks on the metal tip.

What is the difference between the press for NSHVI and the press for power terminals?

Presses for NSHVI (sleeve tips) have a narrow rectangular matrix profile, forming a square section. Power presses use hexagonal or oval matrices to create a round or close to round compression along the entire circumference of the sleeve.