The CCTV industry is becoming more and more popular as people pay more attention to security in their homes and businesses. To ensure CCTV cameras work well, it is important to use a power supply to provide power. How to power them?
There are three popular power supply modes: Independent power supply; Centralized power supply; and POE power supply.
Independent power supply Mode
Independent power supply mode means that one power adapter is powering one security camera independently. It uses a 12V DC power adapter next to each camera.
Following is the diagram:
Advantages of Independent Power Supply
1. Easy to maintain. An independent power supply system is easy to install, protect, and replace. Since each camera connects with an independent power supply, it’s quick to eliminate the faulty camera when it fails. It’s also very convenient to replace the power adapter if the failure is caused by the power system.
2. Avoid the paralysis of the whole monitoring system. Once there is a problem with the power supply system in the centralized power supply mode, without the use of UPS, the entire monitoring system will not work properly. In the independent power supply mode, one or more cameras will stop working due to the power supply failure, which can avoid this kind of paralysis.
Disadvantages of Independent Power Supply
1. High cost. Setting up more power supply will increase the cost. Installation costs will also be higher as it requires more time and labor costs.
2. Inconvenient for centralized control. This mode causes inconvenience for centralized control. It’s difficult to control them all as the power supply system is independent. It is stressful to operate the cameras one by one.
3. Anti-jamming is weak. As there’re more power supplies in the system, its anti-jamming capability is weak.
Power supply suitable for independent power supply mode
Centralized Power Supply Mode
Centralized power supply refers to using 12V switching power supply to run CCTV cameras. In modern installations with analog cameras, the power supply box is centralized to all installed cameras. The power supply box could be installed in the monitoring room or any other relevant setting in the facility.
Compared with the independent power supply, the main difference between them is that one power supply can power multiple cameras in the centralized power supply. There is a distance limit of 100 meters for the cameras and the power supply in this mode.
Here are the steps involved in setting up this power supply system:
1. Connect a 12V power supply box to the AC power, and then integrate the 2*1.0 red and black power cables through to the camera.
2. We also have to ensure that the cable connects the power supply and camera with a screwed power cord.
The diagram of the centralized power supply is as follows:
Advantages of Centralized Power Supply
1. Competitive in Cost. Although the centralized power supply mode tends to use more cables. The centralized power supply mode is more cost-effective with a high cost and performance rate.
2. Ease of installation. With the centralized power supply mode, the cable connection is simple and manageable for construction.
3. Lower energy consumption. Recent case studies have shown that the centralized power supply mode asks for lower energy consumption.
4. Longer transmission distance. The centralized power supply distance is about 30 meters, and it can reach up to 100 meters by laying oxygen-free pure copper wires.
Disadvantages of Centralized Power Supply
1. Troubleshooting is difficult. It will take more time to troubleshoot the whole line if there’s a problem.
2. May cause the whole system paralysis. In the centralized power supply mode, if the power supply fails and the UPS is not used, the entire CCTV system will be paralyzed.
Power Supply suitable for CCTV centralized power supply mode:
Power over Ethernet(POE) power supply mode
Power over Ethernet(POE) is a technology that passes the power over twisted-pair Ethernet cable to the power devices(PD), such as wireless access points, IP cameras, and VoIP phones in addition to the data that the cable usually carries. It enables one RJ45 cable to provide both data connection and electric power to PDs instead of having a separate cable for each. This mode is available when all the powered devices meet the IEEE 802.3bt standard(or other PoE standards).
Following is the diagram of Power Over Ethernet mode:
Advantages of POE Power Supply
1. With better security. Compared with independent power supply and centralized power supply, POE power supply is safer. Standard POE uses the smart protocol to supply power. If you insert a non-powered device or the line sequence is wrong, the switch will not supply power.
2. Easy for wiring. In the above 2 power supply modes, the line spacing between strong and weak levels is greater than 50cm to guarantee safety. It’s complicated and needs more labor costs. The POE power supply wiring is easy and simple.
3. Longer transmission distance. The 15V POE switch can supply power for 100 meters, and 48V can supply power for 250 meters with the 10M network. If a 48V series power supply switch is used, it can even supply power with a distance of 300~600 meters.
4. Easier to maintain. POE power supply mode is convenient for centralized management. We can power off and restart the cameras individually by plugging in and out the cable from the POE switch.
Disadvantages of POE Power Supply
1. High cost. POE power supply is an intelligent power supply mode, which requires more related technologies and equipment, the cost will be higher than the above 2 modes.
2. More requirements for the environment. POE power supply requires a stable network, otherwise the system may not work properly. Moreover, the POE power supply mode requires all the power devices are meet the PoE standard, which has limitations.
The above 3 power supply modes are the main mode in the CCTV market, with each having its advantages and disadvantages. In practical applications, it is necessary to select the appropriate power supply method according to the environment, cost, and stability. Or use different power supply methods to maximize benefits.