Tires: description, marking

Tires electrical are necessary for connecting individual elements of electrical installations into a single whole.

Definition

Tires electrical connecting allow you to combine all the elements of the electrical installation into one. In fact, they are conductors, whose resistance is at a low level.

With a combination of several tires at one point, they talk about busbar trunking. As a rule, they are installed on insulators, which serve simultaneously as supports. He hides in a special box (channel). Due to this, it is protected from environmental factors. The busbar trunking must always be resistant to the arising dynamic and thermal loads, the shock current of the mains.

Tires electric are executed in several executions. For their division into species, several classifications are provided.

By the way of execution, flexible and rigid tires are selected. They are called flat and tubular. Flexible tires do not twist. They should not have a high degree of traction. And the degree of traction of all wires should be the same. Under the influence of temperature, the length of the tire can vary. Therefore, rigid models are equipped with flexible bridges, which must compensate for these changes. In addition, they are equipped with vibration dampers.

In addition, electric buses can be insulated and not insulated. Already from the name it is clear that in the first case the tire has a layer of insulation, and in the second - no.

Classification of tires according to the shape of the section

According to the shape of the cross-section, electric buses are divided into the following types:

• Tubular.

• Rectangular.

• Boxed.

• Two-way.

• Three-way.

Flat tires with a rectangular cross section heat well. Their use is advisable in a network with a high current strength (from 2 thousand to 4,1 thousand amperes). In such cases, they join in groups of several pieces. In this case, a two- or three-lane bus is formed.

The busbars have a number of disadvantages:

• It is difficult to carry out installation work.

• Inductive current, which is distributed unevenly.

• Low ability to withstand mechanical influences.

• Decreased ability to cool.

• Low resistance to short circuits.

In a network with a voltage of 10-35 kilovolts, box or flat products can be used. The most effective is considered tubular. It has a number of advantages. It is strong, it takes away heat well. The electric field around it is distributed evenly. Due to this, no corona appears.

Types of material for the manufacture of tires

Depending on the material from which the tire is made, the following electric tires are distinguished:

• Copper.

• Aluminum.

• Steel.

• Steel-aluminum.

The latter option is a core made of galvanized steel wires, around which are wired aluminum wires.

Aluminum tires have the following advantages:

• Resistant to corrosion.

• Have a high index of electrical conductivity.

• Light weight.

• Their cost is lower than other species.

For their production, plastic grades of aluminum are used with a minimal amount of impurities. Low-alloy alloys of aluminum, magnesium and silicon can be used. Additional elements allow to increase strength, ductility, elasticity.

Copper tires can contain up to 99.9% copper in their composition. Such products are labeled M1. Widely used brands of CMT and CMT, which are made from an oxygen-free brand. They differ in the degree of softness. The first two letters of the marking of the ShMM and the CMT designate "The copper bus". Further, the letter "M" characterizes soft products, "T" - solid.

Marking with alternating three-phase current

Identify the elements of electrical installations will help "hints", which are expressed in the color and letter designation of tires and wires. They are not chosen by chance. They are regulated by standards.

There are two ways of coloring the tires. The first implies that the labeling of electric tires is applied at the manufacturing stage. The manufacturer uses isolation of different colors. The second is suitable in cases where the product has one color. In such situations, a colored electrical tape is used, with which different phases are noted.

In the case of a three-phase current, the marking will look like this:

• Phase "A" is colored yellow.

• Phase "B" is colored green.

• Phase "C" is colored in red.

Designation of conductors

The earth conductor is marked PE. It is always indicated by a yellow-green color. Colors go by longitudinal lines. Moreover, the use of these two colors is forbidden by GOST. A neutral color is used for the neutral and medium conductor (working) with the N marking.

When connecting zero protective and working conductors combine all three colors. The marking in this case looks like PEN. The conductor is executed in blue, and at the end and at the connection points a strip of yellow-green color is executed. At present, it is permissible to perform the opposite coloration: a yellow-green conductor with a blue stripe on the end.

Letter marking

Correctly read the circuit, identify the type of bus or wire will help the letter designation. Like colors, letters have their own interpretation.

Electric wires and buses with alternating current are deciphered as follows:

• L - conductor of a single-phase network.

• L with digits 1, 2 or 3 - conductor in a three-phase network.

• N - zero conductor (or neutral).

• M is the average conductor.

• PE - grounding conductor (protective).

• PEN - combined zero conductors (protective and operational).

With a constant current, the notation will have the following form:

• L + - conductor of positive (or positive).

• L- conductor negative (or negative).

All these markings and symbols are mandatory. They are regulated by the regulations.

Remembering all this at once is difficult. But an experienced electrician knows all this. Such a marking will allow you to determine where and what is connected. A simple person this will be enough to understand, for example, what kind of tire for automatic devices is needed. It may be needed when repairing electrical wiring in the house. To it later it is easy to connect additional sources.