Why does a communication base station use 48V power

Why do we use 48V power supply?

The choice of 48V was to maximize the distance between the user and the end office under the conditions at the time (36V is a safe voltage, and it is unsafe to exceed too much). Later, in order to be compatible with early equipment and reduce costs, the central office communication equipment still used -48V power supply.

What are the applications of -48V DC telecommunications equipment?

Telecommunications equipment draws a lot of current and all of the wires and conductors are very large. Other applications for -48V DC include powering cell towers, local cable TV vaults, and legacy central offices of the various incumbent local exchange carriers (ILECS). Many of these ILECS have been bought back by AT&T.

What are the advantages of a negative 48V DC source?

An advantage of negative 48V is that four 12V batteries connected in series create 48V DC usable as a backup power source. Central telecom stations are known to have elaborate arrays of 48V battery banks. One important aspect of telecom power installations is that the polarity of the 48V DC source is setup to be negative with respect to ground.

Why should you use -48 volt DC?

The use of -48 volt DC also ensures compatibility with safety regulations and guidelines. Standardization plays a crucial role in the seamless operation of complex communication networks.

What is the operating voltage range for -48V system equipment?

For -48V system equipment, the required operating voltage range is -38.4V ~ 57.6V, but in fact we generally require the operating range -36V ~ -72V. The main consideration is that -48V system equipment must be compatible with –60V power supply system, which requires –48~-72V.

Why did Bell choose -48VDC?

In the late 1800’s, most homes of were not yet wired for electricity; in fact, communications beat power to the home in much of the United States. The reason Bell selected -48VDC is because it provides enough in power to support a signal, but not enough to be dangerous.