Choosing the right wire and cable depends on their application but there is a standard chart that indicates the specifications and size and differentiates the low voltage from the high voltage wire and cable.
Cables, components, and connections specific to these technologies are used for low current circuits.
The ability to make these connections makes the process of installing low current systems such as telephone lines, fire alarm systems, CCTV, and burglar alarm systems much easier.
Low voltage wire and cable size
A high-quality connection in these systems will reduce the amount of audio transmission (on the phone), images (CCTV camera system), (central antenna signal), and fewer errors.
On the other hand, the weak currents in these systems lose their properties mainly under the influence of environmental factors, for example, in the cables of these systems, the length of the cables, the induced waves of electrical equipment, the surrounding magnetic fields and the cables adjacent to them, the temperature Elevation and even lightning can affect the quality of its work.
Unlike light and socket wires, wire cross-section is an important factor when choosing conductors.
Conductor cross-section is not so important in these types of systems, where protection of conductors and environmental factors are important in the selection of cables.
The interference caused is important and the term cable is used for these systems because the conductors are separated from the surrounding environment by at least two shields.
In this chapter, the definitions and common connections for low current systems are followed.
Low voltage cable size chart
These cables are widely used in telecommunication circuits and can be divided into two types: unshielded (UTP) and shielded (STP).
Coax cable: These cables have good immunity to interference and harmful environmental factors and their components are shown in the diagram below.
This type of cable is used in TV aerials and CCTV systems.
The two main types of these cables are RG95 and RG6.
Power cables and fireproof cables: This cable is used in control circuits for tracking and fire alarm systems.
Fire alarm circuits should not be interrupted during a fire.
An example of such a cable can be seen in the picture.
The different types of wire and cable, low, medium, and high voltage, are usually distinguished by size and cross-sections.
Low Voltage Landscape Wire
The low-voltage multi-core cable in the four-wire cable is a kind of cable.
Normally, the cross-sectional area of the three wires of the cable is the same, and the cross-sectional area of the fourth strand is smaller.
The smaller value of this wire is usually one grade compared to other wires, but in some cable sizes it is several grades less than others.
The standard cart of the low voltage wire and cable is organized by calculating the numeric specification of the product, indicated with size of wire and cable, in standard condition.
In fact, a cable refers to various metallic conductors capable of conducting an electric current and being isolated from the surrounding environment by an insulating material.
The cross-sectional area of a cable conductor and the type and thickness of insulation and other layers within it depend on the environmental conditions, the amount of current, the voltage, the type of ground and the applied mechanical force to the cable.
Low voltage wire size chart
The temperature is an important factor, affecting the numeric specifications of low voltage wire in the standard chart, depending on the size of wire, which can also affect the voltage drop.
The voltage drop on the steady-state cable uses the formula Vd=√3.I.
(RCosφ+XSinφ)L, which includes the Vd voltage drop, R the cable resistance of each phase under alternating current, I the maximum steady-state current , X the reactance of each phase cable at each I phase Cosφ is also the power factor at full load and finally L is the length of the cable.
