How many cameras can be powered by a PoE switch?
With the development of technology, many now use the camera support PoE power supply network monitoring in construction, in order to reduce the cost of wiring and more convenient, most of the project will consider using PoE power supply. However, the initial contact with the PoE power supply engineering, may not understand the PoE switch, do not know how to choose, but do not know how much power can be given to a PoE switch camera.
Look at a PoE switch can also give a number of camera power supply, to consider two aspects: PoE switch power supply and the total power of PoE switches.
PoE switch power supply can be understood as a single port PoE switch power supply.
PoE switch ONV Guangwangshi has two standards, IEEE802.3af and IEEE802.3at.
IEEE802.3af standard defines the power supply is 15.4W, the IEEE802.3at standard defines the power supply up to 30W, due to different power supply standards, the power supply of a single port is also different. For example, the camera power is 9W, you can use the AF standard PoE switch; if the camera power is 20W, use the PoE switch at standard; if the camera power is more than 30W, you need to use special PoE power module power supply.
The total power of the PoE switch is a very important indicator, directly related to the number of cameras can be taken.
The ONV-PoE31024PF switch Guangwangshi for example, the power supply is 400W, remove the total power loss PoE switch 370W. Under the IEEE802.3af standard, it can be used with 24 ports (370/15.4=24), which can also supply to the 24 cameras; but if it is calculated in accordance with a maximum power supply power 30W IEEE802.3at standard, and most will only give 12 port power supply (370/30=12).
But in actual use, the maximum power consumption of many ordinary webcam is low, basically no more than 15W, if according to the maximum power supply power to set aside each PoE port, there will be some PoE port power use, and some ports but do not get power situation, the PoE switch Guangwangshi support dynamic power allocation, can avoid this situation. So in the purchase of PoE switches, depends on whether the switch to support dynamic power allocation, so that each port is only assigned to the actual use of power, so that it can be more efficient use of PoE switch power supply.
Summary:
1 the use of dynamic power distribution switch, in order to make the highest power efficiency;
2 first understand the maximum power consumption of the power supply equipment, and then use the total power supply PoE switch divided by the maximum power consumption, you can come up with a PoE switch can give a number of equipment power supply.
Poe switch please choose brand Hong Ruiguangxiang