Installing a video surveillance system with your own hands. Part IV.
It's good if you are a person who calculates all the moves in advance.
But what if you are like everyone else and remember about the wires for the video intercom, security alarm and video surveillance system only at the last moment, when the house is already occupied, the furniture is arranged and sitting on the couch, you remember that something is missing?
And there is not enough information about what is being done on the site, what kind of car is parked in front of the house. Therefore, we again remember about our system, especially since the cameras have been selected, the installation sites have been determined and the next step is to go shopping again.
The question arises — why couldn't you buy everything at once? Because the installation sites for the cameras have not yet been determined. Accordingly, the lengths of the cables too (why buy extra or run again for the missing one).
So, we take a tape measure, a sheet of paper, although it is advisable to take a house project instead of the latter, by the way, there should be wiring diagrams, so as not to drill accidentally. And we begin to lay the route from each video camera to the place where the central unit or video recorder will be installed.
This is a painstaking task, but experience shows that it is better to spend half a day just walking, as it may seem from the outside, and then do everything very quickly, according to a proven method, than to stumble upon an obstacle every time and think for a long time how to get around it.
There is an obvious saving not only of time, but also a reduction in the unnecessary number of drilled holes, damaged wallpaper and baseboards.
So, the routes are laid, the footage is calculated, the least that remains is to decide for yourself from an aesthetic point of view where to hide the wire.
There are several options:
— lay it openly, securing it with mounting brackets;
— laying in a cable channel of the appropriate cross-section (the managers will help you choose the cross-section if you tell us how much and what kind of cable will be there);
— lay in plastic corrugated pipes or smooth pipes, while, in the latter case, using the appropriate fittings, brackets, corners, etc.;
— and of course, the ideal option is to do the wiring openly, without particularly caring about aesthetics, before carrying out plastering work.
At the same time, I strongly recommend taking photos of all the stages, so that you don’t have to remember later how the cable goes and whether you can hammer a nail into this place for a picture.
And now you can proceed directly to purchasing cable products, and this is where you will need a manager’s consultation.
Although everything is simple here.
Video surveillance systems use radio frequency cable type RK-75, and all its derivatives, which differ in both technology and name.
It is necessary to remember one thing, the more copper the cable contains, the better the signal it can transmit and over a longer distance. It is not recommended to use a cable with aluminum foil and steel braiding, it is intended for transmitting high-frequency signals. I will make a reservation right away, a good cable is always expensive (copper is always expensive). The central core is better if it is in the form of a mono core.
About the power supply of cameras.
Most often, the power supply for all video cameras is 12 volts DC, and consumption can reach 0.8 — 1.0 A. at night (this is in the case of using cameras with powerful IR illumination). For power supply, a cable of the SHVVP type with a cross-section of 2×0.75 is usually used. If you lay the cable in one line (like beads on a string), then you can save on cable.
If this type of laying is not possible, a «star» cable laying scheme is used, when a power cable is laid in parallel from each camera (similar to laying a video cable).
Thus, we have laid a couple of cables — a radio frequency cable and a power cable.
Let's take a break and start thinking about the video recording system.