The quality of installation and maintenance of a video surveillance system completely depends on which wires are used for the cameras. To select the most suitable option, you will need to study the available types of cables, their advantages and disadvantages, as well as familiarize yourself with the selection features and installation recommendations.
CCTV cable classification and functions
To choose the right cable for video surveillance, you should know in advance how its most popular varieties differ. The speed of information delivery from the camera to an additional element, for example, a microphone, depends on this detail. For each device, it is necessary to select a separate wire that matches it in terms of characteristics.
Coaxial
Coaxial cable designed for video surveillance is ideal for connecting to analogue devices. Outwardly, it resembles a wire connecting the antenna to a TV or other equipment. Its main advantage is maximum strength and protection from any mechanical influences due to the presence of a shielding shell, which also eliminates unnecessary interference and noise during the operation of the indoor or outdoor camera. Such wires are divided into several types and differ in technical characteristics.
The most inexpensive options are those with a small conductor cross-sectional diameter, for example, RK-75-1.5 and RK-75-2. Models numbered RG-6 and RG-11 are used for long distance laying because they have a thicker section. In addition, they are distinguished by the degree of flexibility, insulation thickness, the number of shielding shells and the level of signal attenuation.
Combined
The combined option is required to connect multiple surveillance devices to a power source located in one location. It is suitable for digital and analog devices, it is considered a subspecies of coaxial cable and is not inferior to it in terms of strength. The element consists of several wires twisted together, due to which it is able to provide convenient and fast data access to all parts of the system.
Models are distinguished by marking, consisting of combinations of numbers in combination with letters. The number in front of the letter type designation determines the number of wires under the coating, as standard it is 2 or 4 pieces. Decimal fractions after the cross indicate the cross-sectional diameter of the core. Its standard value is 75 ohms and must be the same for the camera, receiver and cable for the signal to be transmitted cleanly and without interference.
Twisted pair
Twisted pair is used for remote video surveillance, these wires are capable of transmitting information at a distance of up to 3 km. The advantage of the cable is its versatility, since all the necessary conductors are contained in it under one braid. It allows you to connect multiple devices at once and is the most convenient option.
Fiber optic
Fiber optic cable is suitable for various types of video surveillance systems, since it is considered the most durable when compared to analogs. These wires are not subject to electromagnetic vibrations and are capable of transmitting data over long distances without signal attenuation.
Fiber is most often used for mounting cameras in large offices and industrial plants.
Installation tips
The specifics of installing the cable depends on the method of laying, which can be internal or external. If the wires are installed indoors, they should be made less visible and placed so that they are not subject to physical damage. For protection, use special cable channels or corrugation, which prevents the ingress of liquid and exposure to high temperatures.
The outdoor cable for installing video cameras must be fixed on walls, fences, poles and other supporting structures. It can also be laid through the air, suspended from cables, in pipes or trenches under a layer of soil. It is necessary to protect the wires lying on the surface with the help of structures made of plastic or metal. During installation, you should follow the basic rules:
- the diameter of the cable should be half the diameter of the tube through which it is pulled;
- an optical wire for video surveillance is used by choosing the elements of the maximum length;
- the cable route is made as straight as possible without sharp turns;
- for installation, wires with a minimum resistance are chosen, supplemented with high-quality connectors;
- CCTV over a twisted pair cable is not parallel to the power lines.
When installing optical and other wires on the street, the conditions of their operation are taken into account. This includes high humidity, changes in temperature conditions, as well as exposure to UC radiation in combination with mechanical stress.
Criteria for choosing a cable for video cameras
It is important to select the correct cable for your CCTV camera to ensure the stability of the entire system operation. For IP devices, it is better to use UTP wires with RJ-45 connectors, analog devices are well combined with coaxial elements if the distance between the recorder and the device is no more than 100-300 meters.
If signal transmission and power supply are carried out using one part, a combined option would be ideal. When it comes to installing a large number of devices, it is worth giving preference to options for the STP, UTP or FTP format and supplementing them with anti-interference.
Outdoor devices need wires with protective sheaths made of durable polyethylene, internal ones are suitable for analogs with a PVC layer.
When wireless is better than wires
A wireless connection is used when there is no way to lay wires, for example, if they must pass through a river, into a building on the opposite side of the street, or through the territory of someone else's site. The solution to the problem is video senders or data transmission using infrared channels. The second option is used in the operation of remote controls for TV, air conditioners and other equipment. For the image to be transmitted via infrared communication, there must be a line of sight between the devices and there must be no short-term interference.
Radio links for wireless connections are considered to be the most cost-effective way of connecting than wire for standard CCTV cameras. Video senders are a set of signal transmitters and receivers. Simple models of such devices cost from $ 60, they are distinguished by low power and broadcast distance up to 50 meters. The most expensive analogs make it possible to increase the distance between the recorder and the receiver, as well as to turn on a larger number of cameras. The way these devices work is not complicated.
Transmitters and receivers do not require installation of auxiliary drivers with connecting cables. Wireless devices transmit a signal as imperceptibly as possible, while the information will continuously go to the recorder.
Cable for connecting TV to the recorder
If the video signal is to be output on a TV screen, separate wire types are required to connect the camera to it. For this purpose, you cannot use a cable for conventional analog video surveillance, it is better to give preference to other available options:
- HDMI. Capable of broadcasting video and audio up to a distance of 50 meters, suitable for indoor installation, as it is exposed to the weather.
- VGA. A computer-type video connector that transmits an image at a distance of up to 20 meters is not flexible and thin enough.
- RCA. Mainly used for audio connection, not suitable for good video signal transmission.
You can also solve the problem using a regular wireless mouse, insert its adapter into the USB port from the recorder and move the cursor over the TV display. This method is considered the most convenient for setting up and managing the entire system for video surveillance with a communication distance of up to 15 meters. It should be borne in mind that an ordinary cable is not connected to the TV, which is suitable for connecting a video camera; in such a situation, you will need to purchase individual elements and accessories.
Benefits and cons
Most often, coaxial and combined cables are used for cameras and video surveillance installations. The first option is mainly used when installing analog devices, therefore it is also called radio frequency. Of the advantages of such wires, they note increased resistance to various interference, reliability, the ability to transmit both audio and video signals in combination with an affordable price. They also have their drawbacks, including the high cost of connectors, a tendency to damage at bends, and restrictions on the distance for installation.
Combo cables are a more advanced analogue of coaxial cables and are complemented by two-conductor wires for power and auxiliary parts of the system, such as microphones. The list of advantages of such wiring include the absence of the need for unnecessary elements, complete protection against any interference, ease of installation and the transmission of signals of both types. The disadvantages of combined options are high cost, quick wear and the ability to use them only over short distances.
The combo cable is suitable for IP video surveillance and is considered the most rational option.
