Understanding Power Supply Essentials for Analog CCTV Systems

Power Options for CCTV: Adapters vs. Distribution Boxes

Every CCTV camera requires a power source, and in India, power distribution boxes and Bureau of Indian Standards (BIS) certified power adapters are commonly used in security camera installations. For setups with four or fewer cameras, installers often opt for a power adapter with a splitter. However, for larger installations, a power distribution box is preferred. It's essential to choose a power adapter that matches the voltage and amperage requirements of your cameras.

Choosing Between 12V DC and 24V AC Power Supplies

When it comes to selecting a power supply for CCTV cameras, the choice between 12V DC and 24V AC is significant. Outdoor CCTV cameras typically use a 12V DC power supply, while PTZ (Pan-Tilt-Zoom) cameras often require a 24V AC power supply. Some security cameras may operate on 220V AC power, and 5V DC power supplies are widely used for indoor CCTV systems in Mumbai. The higher voltage of a 24V AC power supply allows for longer transmission distances with less power loss, ensuring that the CCTV cameras receive sufficient power. Additionally, using a 24V AC power supply enables the synchronization of the image vertical frequency across multiple devices.

Ensuring Adequate Battery Backup for Security Cameras

Determining the necessary battery backup power supply for security cameras can be challenging, especially for inexperienced installers. It's a common mistake to underestimate the power requirements, leading to the need for additional power supplies. Security cameras require a significant amount of current at startup, in addition to the power consumed during operation. To calculate the total power supply needed, one should sum the rated power of each camera and then multiply by 1.3 to account for startup current and transmission losses. Furthermore, cable power loss and the overall power budget should be considered.

Example Calculation for CCTV Power Requirements

Let's say we are installing 100 security cameras in a commercial building, with each camera having a rated power consumption of 4W. To calculate the necessary power supply for the CCTV system, we would perform the following calculation:

• Security camera power consumption: 4W x 100 units x 1.3 = 520W
• Adjusted for startup and transmission: 520W x 1.3 = 676W
• Accounting for cable loss and power budget: 676W x 1.3 = 878W

Avoiding Common Pitfalls with UPS Power Supply

When setting up a UPS power supply for CCTV systems, it's important to avoid relying on a single centralized power source for several reasons:

1. When power is cycled to service the camera system, all cameras boot simultaneously, drawing a large inrush current that can strain or damage the power supply.
2. If all cameras are connected to one power supply and it fails, the entire CCTV system will go offline, leaving critical areas unmonitored.

The recommended approach is to divide the power supply among multiple units. Using the previous example of a commercial building requiring 800W for 100 security cameras, the ideal setup would be to use four power supplies, each providing 200W. This way, if one power supply fails, the remaining cameras continue to function.

In conclusion, selecting the right power supply for an analog CCTV system is a critical step in ensuring the reliability and effectiveness of your security setup. By understanding the power requirements of your cameras and planning for adequate power distribution, you can maintain a secure and stable surveillance system.