In the construction of computer rooms, the layout of power lines and network lines is a very important thing. These two types of equipment are well-equipped, the computer runs normally, the failure rate is low, the teachers are also comfortable in class, and the classroom teaching efficiency is greatly improved; otherwise, the faults are frequent, and the quality of classroom teaching is discussed!
Power cable layout
In the exchange, the author found that the 220V AC power cord of the student machine in many school rooms is equipped with several porous sockets in series. This connection is very simple, but its drawbacks are many: connect with each porous socket With 4 computer meters, 20 computers are connected in series with 5 porous sockets. If these 20 computers are turned on at the same time, the huge inrush current generated can easily burn the AC fuse of the first porous socket. Some people may say that the chances of 20 consoles being turned on at the same time are very small, but if the monitors of these 20 computers are not turned off after the last use (because they need to be manually turned off), then only 20 monitors will be turned on at the moment of total power-on. The resulting inrush current is also sufficient to cause the same fault.
The correct way to route the power cord is to group the points. Using a standard power sheathed cable, connect a 20A three-core GB socket (ie a separate socket embedded in the wall) as a point every 1.5 meters or so, and then connect the above porous socket to this point. As still the case above, adding five such three-pin sockets will solve the problem. There is also a group of 10 (or 10 or 16 units as the actual situation) controlled by an air switch, the entire computer classroom can be divided into 4 to 6 groups. Nowadays, some school power cord construction is more important than this. Not only do each porous socket be pulled separately, but also the display power supply is controlled in groups.
Network cable layout
The first thing to consider when laying out the network cable is how to manage the hub and switch. I have seen many computer rooms in order to save the network cable, adopt the method of hub serial connection, for example, placing the first station under the teacher's podium, placing the second station under the student machine No. 15, and so on. This is a bit like the serial type of the power socket above. Although the network cable is saved, there are many defects: it is not convenient for centralized management and is prone to failure. And the more the series connection, the more the network signal is attenuated. Therefore, in today's computer room, hubs and switches are usually placed next to the teacher's machine or server (specially a cabinet), which greatly facilitates management and also reduces the network failure rate.
Need to be reminded that the RJ-45 heads at both ends of each network cable must be made according to the standard, especially the 100M network environment computer room that is now very convenient to implement. The author found that many newly installed computer classrooms (including electronic reading rooms, etc.) affected the communication quality due to the non-standard RJ-45 head. According to the 568B specification, the arrangement of the 8-core wires is white orange, orange, white green, blue, white blue, green, white brown, and brown.
The above-mentioned power cord and network cable layout should be implemented in the first step of the installation in the computer room. It is the basis for ensuring the safe and stable operation of the computer room in the future. It must be paid enough attention (there are many units in the computer room after the computer is installed). wiring). According to the above preferred solution, that is, the host power line grouping individual type, the display power line grouping type, the switch centralized management type (conditional optional stacking switch), according to the calculation of the author, a computer room with 60 student machines, the power cord (including porous sockets, multiple sets of air switches on the wall), network cables (excluding switches) will require an investment of more than 10,000 yuan, and such investment will be highly efficient.