By: Arthur Cooper
Submitted: 2011-05-13 11:46:37 | Word Count: 664
If you own a digital video security system, chances are you also own Closed Circuit TeleVision or CCTV power distribution boxes. These are literally the powerhouse for the digital video cameras and illuminators used in complete systems.
There are three major components to a digital video security and surveillance system; the cameras, the Digital Video Recorder or DVR, and the monitor(s).As far as power requirements are concerned both the DVR and the monitor normally take care of themselves. In other words, they both have household 110 AC plug-in cords, so all you need to do to get them power is plug them into an outlet (we recommend a properly rated surge suppressor). The cameras on the other hand, are a different story altogether.
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Most digital video cameras these days require 12 Volts Direct Current or VDC. Some cameras use 24 Volts Alternating Current or VAC. There are some advantages and disadvantages to each. DC will lose its charge much more rapidly and significantly over long cable runs than AC. This is why to this day, the electricity in our home is AC because AC can travel much further than DC without as much power degradation. On the other hand, 12 VDC is a relatively low and safer voltage to deal with.
Nonetheless, a digital video camera can’t just plug into a wall outlet. In addition, whether the camera is designed to use AC or DC power, a special transformer will be needed to “step down” household power. This is where the CCTV power distribution boxes come in.
CCTV power distribution boxes are basically electronic transformers that step down the voltage and current of typical household type (110 VAC) to either a 12 VDC or a 24AC output. Most digital video security camera power distribution boxes come in 4, 8, 9, and 16 channels. Depending on the cameras you use it is possible that you will need to mix and match more than one power distribution boxes.
The CCTV power distribution box either plugs into a wall outlet or is hardwired into the household electrical system. Each individual camera’s pair of power supply wires are connected to screw posts inside the distribution box. Normally the power distribution box is going to be located in very close proximity to the DVR.
This is why Security Camera King’s Siamese 18/2 wire is so convenient. Once the camera cable is run all that need to be done is to strip some of the insulation of the cable to free up the two 18 gauge power wires. They can then be routed to the power distribution box while the coaxial cable and be fixed to a BNC connector and plugged into the back of the DVR unit.
There are many advantages to a CCTV power distribution box. First some units may be expandable to allow more channels. Also power distribution boxes provide a nice, neat, and professional looking installation. No special plugs or leads are required as the individual wire is fixed to a secure screw post. One of the most important features of the CCTV power distribution box is that once it is mounted and the wires have been connected, they are much less likely to be tampered with compared to other types of camera power supplies.
The alternative to using a CCTV power distribution box is to use an individual plug-in transformer type powers supply for each camera. This is a bit tedious if you are installing a 32 camera system and it maybe very difficult to do because there may not be enough wall outlets to support all the transformers
Another alternative is to use a 4 channel output switching supply. This is great provided your camera doesn’t require more than 500mA of power consumption. However, once again, things could get a bit tedious using this type of power supply if you have a 32 camera system. In addition, the ends of the wires need to be fitted with leads that have 2.5mm or 2.1mm plugs.
The bottom dollar here as to what type of power supply to use is determined by your camera, accessories, and how far you will need to run cable to any of these devices. CCTV power distribution boxes are the perfect solution for systems with many cameras while systems with only a few cameras may be better served by the 4 channel output switching supply.
