The main function of armored cable

Armored cable is a cable whose outer sheath is protected by steel tape or steel wire and aluminum wire, so it is called armored cable. This design and packaging is to avoid damage to the outer sheath of the cable during extrusion, resulting in a short circuit inside.

This design can also improve the tensile capacity of the cable and effectively prolong its service life. In addition to being wrapped with steel tape, it can also be replaced with steel wire or aluminum tape. It has excellent magnetic absorption effect and can resist surrounding interference.

Armored cables are generally fixed laying power cables. In simple terms, they are fixed in one place and almost do not move, and the driving force transmits electromagnetic energy.

Armoring has a certain resistance to external forces, and can also prevent mice from being torn, and will not cause difficulties in power transmission through armoring. The bending radius of the armoring should be large, and the armoring layer can be grounded to protect the cable.

The production of overseas armored cables is mainly concentrated in many countries, such as the United Kingdom, the United States, Japan, France, Ukraine, and Southeast Asian countries. As long as there are chemical plants, metallurgical industries, mechanical equipment manufacturing, and power generation Armored cables will be useful in some places.

The role of armored cables

Armored cable refers to a cable with an armored layer of metal composite material. The purpose of adding an armored layer to the cable is to improve the compressive strength, tensile strength, etc. of the cable, and to improve the anti-interference ability of the cable.

Common armoring materials include steel strip, stainless steel wire, aluminum strip, aluminum alloy and other materials. Among them, the steel strip and stainless steel wire armor layer have high magnetization strength, have a very good electromagnetic shielding effect, and can be used to resist low frequency effects. And it can make the laying of armored cables faster and more convenient, and it is of high quality and low price, and has many specific applications.

Armored cable mechanical protection layer can be added to cables of all structures to improve the impact toughness of the cable and improve the corrosion resistance of the cable. It is a special cable designed for areas that are vulnerable to mechanical damage and corrosion. For example, a lot of power engineering cables, with the high-quality electrical equipment characteristics of the original high-density polyethylene cables plus armor, can be laid by any method, suitable for indoor, tunnel construction, cable trenches and underground direct burial laying, The cable can bear certain external forces of mechanical equipment.

Why should armored cables be grounded?

Because when the cable insulation is damaged, the armor layer will be charged. There is no interference problem with armored cables, and the purpose of our grounding is safety. Grounding at both ends can reduce the grounding resistance, increase the fault current, and make the protection electrical more reliable. The specific analysis is as follows:

1.If the steel strip pierces a certain phase insulation in the middle of the cable, but the outer sheath layer is intact, the steel strip is in a charged state, but it cannot be detected, and it is easy to cause an electric shock accident; if it is grounded, it can drive the protection device to trip. the

2.Although the steel strip of the inner armored cable is not exposed, when the three-phase current is unbalanced, the armored layer may discharge due to the induced electromotive force, and in severe cases, the sheath may be burned. When the armor layer is grounded, it is leveled with the ground potential, and the discharge phenomenon can occur. the

3.After the copper tape shield is grounded as a part of the core insulation shielding layer, on the one hand, it can level the potential of each core shielding layer, and on the other hand, it can also reduce the potential difference between the copper tape and the steel armor to avoid discharge.

4. If it is not grounded, if the current passing through the cable is large enough, an eddy current will be generated in the armored steel strip, and the steel strip will heat up. The current carrying capacity of the cable will decrease and the cable will heat up again, resulting in a short circuit or burning of the cable.