Can the CCTV adapter 12V 5A be used in a CCTV system with a long cable run?

Hey there! As a supplier of CCTV adapter 12V 5A, I often get asked whether this adapter can be used in a CCTV system with a long cable run. It's a valid question, and in this blog, I'll break it down for you.

First off, let's understand the basics of a CCTV system and how power works in it. A CCTV system typically consists of cameras, cables, and a power source. The power source, in our case, is the 12V 5A adapter. The 12V refers to the voltage, which is like the "pressure" that pushes the electrical current through the system. The 5A, on the other hand, represents the amperage, which is the amount of electrical current flowing.

When it comes to long cable runs, things get a bit tricky. You see, cables have resistance. And the longer the cable, the higher the resistance. This resistance can cause a drop in voltage as the electrical current travels through the cable. This phenomenon is known as voltage drop.

So, can our 12V 5A adapter handle a long cable run? Well, it depends on a few factors. The gauge of the cable is crucial. A thicker cable (lower gauge number) has less resistance compared to a thinner cable (higher gauge number). For example, a 16-gauge cable will have less voltage drop over a given distance than a 20-gauge cable.

Let's do a quick calculation to see how voltage drop works. The formula for voltage drop is V = I * R, where V is the voltage drop, I is the current (in our case, 5A), and R is the resistance of the cable. The resistance of the cable depends on its length and gauge. You can find resistance values for different cable gauges and lengths in electrical reference tables.

Say we have a 100-foot run of 18-gauge cable. The resistance of 18-gauge copper wire is approximately 6.38 ohms per 1000 feet. So, for a 100-foot run, the resistance would be 0.638 ohms. Using the voltage drop formula, V = 5A * 0.638 ohms = 3.19V. That means the voltage at the end of the 100-foot cable would be 12V - 3.19V = 8.81V.

Most CCTV cameras are designed to operate within a certain voltage range. Typically, they can handle a voltage between 10.5V and 13.5V. In our example, the voltage drop is significant enough that the voltage at the camera might be too low for it to function properly.

However, if we use a thicker cable, like 16-gauge, the resistance per 1000 feet is approximately 4.016 ohms. For a 100-foot run, the resistance would be 0.4016 ohms. Using the voltage drop formula again, V = 5A * 0.4016 ohms = 2.008V. The voltage at the end of the 100-foot cable would be 12V - 2.008V = 9.992V, which is still on the lower end but might be acceptable for some cameras.

Another factor to consider is the power consumption of the CCTV cameras. If you have high-power cameras, they will draw more current, which can lead to a greater voltage drop. On the other hand, low-power cameras will draw less current, resulting in a smaller voltage drop.

So, what are the solutions if you need to use a long cable run in your CCTV system? One option is to use a higher voltage adapter. For example, instead of a 12V 5A adapter, you could consider a 12v10a DC Power Supply Box or a 12v20a Box Power Supply. These adapters can provide more power and may be able to compensate for the voltage drop over a long cable run.

Another solution is to use power injectors. Power injectors can be placed at strategic points along the cable run to boost the voltage. This helps to ensure that the cameras receive the proper voltage.

You could also consider using a 12v10a 12v Power Box closer to the cameras. By reducing the length of the cable run between the power source and the cameras, you can minimize the voltage drop.

In conclusion, while a 12V 5A adapter can be used in a CCTV system with a long cable run, it's important to carefully consider the cable gauge, the power consumption of the cameras, and the distance of the cable run. If you're unsure, it's always a good idea to consult with an electrical professional.

If you're in the market for a reliable CCTV adapter or any of the power supply options I mentioned, don't hesitate to reach out for a purchase negotiation. I'm here to help you find the best solution for your CCTV system.

References

• Electrical Engineering Reference Manual, various editions
• CCTV Camera Manufacturer's Specifications