Copper cable lug: classification, marking of types and methods of attachment to the cable

For a high-quality connection of the working wire of the device to the network, a good connection must be ensured. In multicore cables, this is more difficult to accomplish than in single-core cables, therefore, in such cases, special cable lugs are used - copper, aluminum-copper or tinned. If the connection is not strong enough, this may affect the quality of the device.

Decoding of markings

Different types of contact fixtures have special combinations of symbols to indicate their main characteristics. The letters indicate the type of material - copper (M), aluminum (A) or brass (L). There may be a combined version, for example, aluminum-copper. The additional letter L indicates that the copper tip is tinned.

Models are also different - angular, T-shaped and regular, made of a metal tube. Further in the marking line are numbers, on the basis of which it is possible to determine the nominal cross-section of the wire suitable for the tip, as well as the diameter of the product.

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Varieties of tips

The selection of products on the market is wide enough to satisfy the needs of both hobbyists and professional electricians. There are many different types of terminals, differing in material of manufacture and other parameters.

Types and their differences

All cable terminals differ in several ways. The main classification is based on the kind of metal they are made from. Due to this there are such types of products:

• copper;
• tinned copper;
• aluminum copper.

Brass lugs are much less common, in most cases, manufacturers prefer copper - it is easy to work with, it is not exposed to aggressive environmental influences. However, tinned metal has the best performance because it is protected against corrosion and transmission loss.

Although the electrical conductivity of copper decreases slightly during tinning, the work is kept at a stable level in the future. Uncoated copper cable lugs will soon oxidize and gradually lose performance characteristics - the connection heats up due to an increase in resistance, which in the future may lead to fire. Based on the markings on the product body, the following types of tips can be distinguished:

1. TM. This is a classic version of the bare copper tubular lug, which is specially made to connect copper wires to a source by crimping. There is the same product, but for bolting. There is no protective coating, which means that it is highly susceptible to corrosive processes.
2. TML. A product of this type is manufactured on the basis of TM. With the help of tinning, the tip is covered with a protective shell that protects the metal from the aggressive effects of acids, moisture and other reagents. The cable is also connected by crimping.
3. TMLs. Lugs with this marking are specially made to simplify the work with wires of flexibility classes No. 2 and 3. The diameter of the product is ideally matched to the same indicator of the cable.
4. TML din. Manufactured to European standard, these bolting lugs feature high quality metal and tin plated finish. The crimping method is recommended.
5. TML (2). Unusual tinned copper lugs for crimping copper cables. The main difference is the use of a double bolt hole, which achieves high contact strength. More often made to order.
6. TML-U. Specialized products for connecting cables with copper conductors to MCCB circuit breakers.
7. TA. Aluminum cable lugs are designed for crimping aluminum cables. They have one hole for connection with a bolt.
8. THERE. The aluminum-copper variety of limit switches has a tubular shape and is designed to connect contacts made of different metals - aluminum wire and copper electric bus. The bolt hole has a copper bush that is carefully pressed to ensure good contact.
9. THERE is welded. The aluminum tip with a copper “eye” is connected by frictional molecular welding.
10. NB. Bolt lugs differ in the way the wire is connected to them - to achieve a good result, do not special equipment is required, the cable is fixed with a bolt screwed into the tube perpendicularly wire. Product material - aluminum.
11. PM. Tinned copper tip that can be connected by either crimping or soldering. Climatic version of the product is T2. Production standard - TU.
12. TML (45). Contra-angle tubular tip made of copper with a protective tin-plated finish. The bolt mounting platform is made at an angle of 45 degrees relative to the base tube.
13. TML (90). The same type of product as in the previous case, however, the difference is in the slope - an angle of 90 degrees is observed here. Contra-angle handpieces are manufactured according to the TU standard.
14. NShP. Special pinned copper end stop made according to DIN European standard. Used to connect copper wires to circuit breakers.
15. NSHVI and NSHVI (2). The clip is made of copper, covered with a tinned protective layer and is used for terminating stranded conductors. There is an insulating material on the product.
16. NShV. Lugs similar to the previous type are made of tinned copper, but they are not insulated.
17. VRPI-M (mom) and VRPI-P (dad). Limit switches are used to form quick-disconnect connections of stranded wires. This is true when the device is movable and is in an area of ​​increased vibration.
18. NVI. Lugs with a two-pronged fork are used for fixing stranded conductors. When disconnecting the contact, you do not need to completely unscrew the fasteners, you can simply loosen the bolt a little and pull out the tip. In the classic version, PVC insulation is used.
19. NVI (n). Fork end stops with nylon insulator.
20. NVI-T. Fork-shaped heat-shrinkable terminations covered with a layer of hot-melt glue as insulation.
21. NKI. Bolt terminals with PVC insulation. Material - tinned copper. There is a variant of NKI (n) with a nylon insulating layer and NKI-T with a heat-shrinkable tube.
22. VNKI. Bolt caps with additional copper sleeve for increased strength and vibration resistance.
23. NSHKI, NSHPI and NSHPI (n). Stud lugs for tinned copper multicore cables with different types of insulation - nylon, normal PVC and self-extinguishing PVC.

In addition to the end products, there are special sleeves, as well as bolt connectors for connecting wires to each other. To fix the twists, use special insulating caps-connectors.

Homemade products

Despite the widest range of cable lugs, sometimes the user is faced with such a situation when certain difficulties arise with the selection of the required product size. In such cases you can try to make the tip yourself - it does not require large labor and financial costs.

For manufacturing, you will need a small piece of tube from the selected material of a suitable diameter. One end of it is flattened and a hole is made in it for a bolt of the desired size. The product is of low quality and may not withstand high loads, therefore, this method can only be resorted to in extreme cases, using such a tip in temporary connections.

Specialized limit switches

Products with the TML (o) marking stand apart among all types of handpieces. Their distinguishing feature is a small diameter inspection hole to control the correct insertion of the cable into the terminal. Most often, however, these clips are used in the production line, so they cannot be found in conventional electrical supply stores.

Mounting features

There are several common methods for attaching a cable clip to a cable. They all differ in complexity, connection quality and the need for additional equipment. Terminals are installed on the wire using the following methods:

1. Crimping - clamping of a tip with a cable inserted into it with special pliers.
2. Fastening using a bolt or screw. Such fixation is possible only in special products designed for this. They have a hole complete with a bolt. The wire is inserted into the lug as far as it will go, and a suitable bolt is fully tightened. Provided that the work is done well, the connection is quite strong.
3. Welding.
4. Soldering.

The simplest method is crimping, however, in the absence of crimping jaws and the need to crimp the power cable, this method will be very difficult. Therefore, you can use soldering or, if possible, screw connection. In industrial conditions, a mechanical or hydraulic press is used for crimping.