Monitoring the power supply configuration, if you don't know it deeply, often causes troubles in your work. The importance of the power supply in the security system is beyond doubt.
How to properly configure the camera power supply of the entire monitoring system?
Engineers often feel that many programs are implemented, and found that the power supply capacity of the original design is not enough, and additional equipment is needed, causing the phenomenon of squashing with the party. In fact, because the camera starts at a moment, the starting current is very large, and the loss of long-distance transmission in engineering, the power required by the surveillance camera is not simply added to the rated power of all cameras.
The correct way is to add the power of the camera of the entire monitoring system and multiply by 1.3 times. This is the actual power required by the camera, and then add about 30% of the loss. Finally, add 30% of the margin. Expansion will be used in the future.
12V centralized power supply is not recommended, but 220W centralized power supply is recommended in places where conditions permit, or 12V independent power supply is used, and 220V socket is installed next to the camera.
for example:
If there is a fixed gun camera in a commercial building, and the rated power of each surveillance camera is 4W, how do we configure the camera power supply?
According to the above calculation method, we calculated that the rated power of the camera is 4W*100 units=400W.
The actual power used by the camera is 400W*1.3 times=520W
After considering the loss, the power required by the camera is 520W*1.3 times = 676W
With the power supply margin, the power supply that the camera finally needs to be configured is 676W*1.3 times = 878W
Summarized as follows:
The power required to be configured by the camera = the rated power of the camera *1.3*1.3*1.3
(Note: If the monitoring distance is extremely long, it is necessary to increase the power supply appropriately and increase the power supply voltage)
Monitor the configuration of the camera power supply, what are the taboos?
The taboo is that the entire monitoring system shares a power supply. The reasons are as follows:
1. When the system is being repaired, it is often necessary to turn the power on and off. All the cameras start at the same time when the power is turned on, and the starting current is particularly large, and the impact on the power supply is great, and the power will be burned seriously.
2. All surveillance cameras share one power supply. When the power supply fails, the entire closed-circuit monitoring system is paralyzed. In particular, some important entrance and exit images cannot be monitored, which may cause unnecessary trouble.
So what should be the right approach? As the above example, a commercial building has 100 fixed cameras, which require a total of about 800W of power. The correct configuration should be 4, each 200W power supply. In this way, when a power supply fails, the camera of the important entrance and exit can be connected to other good power supplies without affecting the operation of the entire system.
What issues should I pay attention to when selecting the power of the surveillance camera?
First, when connecting the camera to the power supply in the centralized power supply scheme, do not connect the camera with a long distance and the surveillance camera with a close distance to the same power supply. If connected to the same power supply, the power supply voltage is high, the camera will be burnt at a close distance, the power supply voltage is low, and the camera with a long distance has no image. Nowadays, the camera basically adopts a wide power supply design, and can work stably for a long time in the range of DC input voltage of 12V-36V, completely eradicating the damage caused by unstable input voltage (such as surge) to the camera. This problem can be solved well. It is an ideal solution for centralized power supply to cameras.
Second, if the monitoring distance is too far, you need to configure a higher voltage power supply, such as 30V, 36V, etc., or even directly for 220V AC, and then transform to the front end.
Explore several ways to supply video surveillance
There are three common types of power supply for video surveillance, namely point-to-point power supply, centralized power supply, and PoE power supply. Let's take a look at their respective advantages and disadvantages.
01 point to point power supply
Point-to-point power supply means that 220V AC is directly taken from the monitoring room, and DC12V or AC24 power is connected to the camera.
Advantages: 220V AC has low voltage loss during transmission and strong anti-interference ability.
Disadvantages: Each point must be installed with a power supply, which is more troublesome to construct.
02 centralized power supply
The centralized power supply mode refers to the centralized power supply to the front-end load by using a 12V switching power supply in the monitoring room or at an intermediate point.
Advantages: Convenient construction, easy maintenance, saving power costs
Disadvantages: DC low-voltage power supply transmission distance is too high, high voltage loss, poor anti-interference ability during transmission, easy to cause front-end camera voltage instability, less than 12V and so on.
03PoE power supply
PoE power supply refers to the technology of providing DC power to other devices without any changes to the existing Ethernet cabling infrastructure. This method is mainly applied to a high-definition network digital monitoring system or a wireless AP network.
Advantages: Reduce cost, flexible deployment, single port maximum power up to 30W.
Disadvantages: The quality of the network cable is high and the transmission distance is limited.
Precautions:
When using an infrared camera, centralized power supply is not recommended. Because the current is large when the infrared is turned on, the centralized power supply method is difficult to ensure that the infrared effects of all the cameras are good. Point-to-point power supply is sometimes cumbersome to find, and you need to find a suitable power point. The PoE power supply mode is now used more often, and is often powered by a PoE switch or a power supply, which can save labor costs.
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