There are three main methods to supply power for security cameras:

1.centralized power supply;

2. Point-to-point power supply;

3. POE ( Power Over Ethernet).

Before you decide to choose them, it is better for you to know about them clearly.

1)Centralized power supply

In this method, the source equipment is centrally installed in the power room, and electric power is supplied to each device after the unified transformation distribution.

For CCTV system, centralized power supply means in a monitoring room or a middle point, using 12V power to supply cameras.

Advantages: 1. Easy to maintain; 2. Better for unified management  and management.

Disadvantages: 1. Preliminary preparation is complex; 2. DC low voltage power supply, it will cause voltage loss if the distance is long; 3. Anti-interference ability is bad during transmission.

2)Point-to-point power supply

In this method, it needs to install DC12V power adapter next to the camera, and power camera separately.

Advantages: 1. low voltage loss of 220V AC during the transmission; 2. Has a great anti – interference performance

Disadvantages: There is a trouble that each point need to be installed a power supply.

3)POE (Power Over Ethernet)

PoE refers to the provision of DC power supply technology for other devices without any changes to the existing Cat.5 Ethernet cabling infrastructure, which is mainly used in high-definition network monitoring systems.

Advantages: 1. lower costs; 2.flexible deployment and convenient installation; 3. single-port maximum power up to 30W.

Disadvantages: 1. Require better quality of network cable; 2. Transmission distance is limited; 3. Equipment power can not exceed 30W.

Some tips:

1.When you use many pieces of infrared camera, it is not recommended to use centralized power supply. Because the current is large when IR LED are working. Centralized power supply is hard to ensure all of IR LED working normally.

2.Using point-to-point power supply, you can save some cost of the cable. But it is no double that after-sales maintenance is a more difficult than centralized power supply.

3. When there are numbers of cameras and power supply distance is less than 100 meters, it is recommended to use PoE power supply. It is more convenient, but pay attention to the quality of power supply equipment and cable.