After completing the installation of network surveillance systems, we often encounter issues like connection failures, image loss, and lag during the debugging process. Many times, we immediately consider problems with the network or the devices themselves. However, power supply issues should also be considered. Below are some important points regarding the power supply for surveillance cameras that you need to pay attention to.
1. Separate Power Supply
If you are using a separate external 12V DC power supply (24V AC for PTZ cameras), check whether the power supply is functioning properly and whether the output power is sufficient. Cameras typically use 12V 2A power (with supplementary lighting, typically around 12V 3A), and PTZ cameras use 24V 4A AC power supply.
In most cases, the system works fine during the day but fails at night (when the infrared or supplementary lighting turns on, such as for full-color day/night cameras with built-in white light). Power supply output not meeting the required standard is often the cause of such issues.
2. Centralized Power Supply
If you are using a centralized power supply module, check whether the output power can meet the requirements of all the cameras (e.g., for 6 cameras, you need at least a 12V 15A centralized power supply). Also, check the distance between the cameras and the centralized power module. The longer the cable, the greater the power loss. It is best to keep the distance within 30 meters or increase the output power of the centralized power supply.
3. POE Power Supply
If you are using POE (Power over Ethernet) for power supply, check the following:
- Whether the network cable is made of pure copper or oxygen-free copper.
- Whether the diameter of the network cable meets the standard (recommended 0.5mm² oxygen-free copper).
- Whether the POE switch output power is sufficient and whether the power supply protocol between devices is compatible.
POE has three main protocols:
- 802.3af/15.4W – For standard cameras.
- 802.3at/30W – For standard cameras or low-power PTZ cameras.
- 802.3bt/90W – For high-power PTZ cameras.
Select a POE switch that meets the required specifications for your devices. Make sure the transmission distance is appropriate for your POE devices’ protocol type. Non-standard POE switches may cause issues.