The communication power supply is 48V, why does the communication power supply use 48V voltage?

The current voltage level of the communication power supply.

It is mainly divided into DC -48V (+24V), AC 220 380V, and DC 380V in the initial stage of development but with good prospects.

2G macro stations generally use -48V, which is mainly caused by historical reasons. The earliest communication network used is the ** network, the phone is powered by the telecommunications authority, and the choice of 48V is to increase the distance between the user and the terminal office as much as possible under the conditions at that time (36V is the safe voltage.

More than too much is not safe). Later, in order to cover the early equipment of the cherry blossom front and reduce costs, the central communication equipment still used -48V power supply. With a negative power system, the positive grounding is just conventional.

It turns out that there is a saying that there is a large amount of negative charge in the air, according to electrochemistry.

Knowledge, positive electrode grounding can adsorb negative ions in the air.

Thus protecting the casing of telecommunications equipment from corrosion. Actually, this statement is not very true. Galvanic cell reactions and electrolytic reactions can cause the device to rust, but because they exist in a microscopic form on the device, they have little effect.

For example, the network of a non-communication system is negatively grounded (e.g. the computer you are using), but it is not rusty. And the -48V is isolated by DC DC, and the DC DC output is the negative electrode grounding, and there is no corrosion and rust on the veneer. So no matter which pole is grounded, it's the same.

The macro station of 3G equipment is still dominated by -48V, but most of the 3G services occur indoors, and in order to reduce the cost of site construction, the indoor AP-POE and outdoor RRU+BBU coverage methods will become the main methods of 3G distribution. The length of time the -48V power supply has been in existence may be worth considering.

In addition, with the massive growth of data services, large-scale IDC data centers will become an urgent need, and the power supply security and cost control of IDC data centers will be controlled.

It is also a direction and focus of everyone, and the scale promotion and use of HVDC power supply will be slow.

At present, the voltage level of communication power supply is mainly divided into DC -48V (+24V), AC 220 380V, and DC 380V is in the initial stage of development but has a good prospect.

The one above is too detailed! Identity.

The power supply of the communication room -48 is not the same as the 48.

The power supply mode of the communication room adopts the 48V power supply system, and all equipment is powered by the ready-made 48V power supply, which is the safest, most reliable, most economical and most reasonable solution.

In terms of the power supply system of the communication bureau station, China has already completed the unification of the power supply system with DC 48V power supply as the basic voltage, the original 60V power supply system has been eliminated, and the long-distance trunk optical cable bureau -24V and +24V system have been transformed or unified into 48V power supply.

The use of a -48V power supply is due to historical reasons. The earliest communication network used was the ** network, the telephone was powered by the telecommunications bureau, and 48V was chosen to increase the distance between the user and the terminal office as much as possible under the conditions at that time (36V is the safe voltage, and it is not safe to exceed too much). Later, in order to be compatible with early equipment and reduce costs, the central communication equipment still used -48V power supply.

Similarly, with a negative power system, the positive grounding is just conventional. Originally, there was a saying that there is a large amount of negative charge in the air, and according to electrochemical knowledge, the positive electrode grounding can adsorb negative ions in the air, thereby protecting the shell of telecommunication equipment from corrosion. Actually, this statement is not very true.

Galvanic cell reactions and electrolytic reactions can cause the device to rust, but because they exist in a microscopic form on the device, they have little effect. For example, the network of a non-communication system is negatively grounded (e.g. the computer you are using), but it is not rusty. And the -48V is isolated by DC DC, and the DC DC output is the negative electrode grounding, and there is no corrosion and rust of the veneer.

So no matter which pole is grounded, it's the same.