because the termination and relays in side the telecoms penal needs for DC supply to continues the protection equipment and relay and purpose of telecoms
dc
To prevent the equipments from lightning strokes. Because the cloud is negatively charged at bottom it requires a zero or a positive potential to discharge, and it selects the ground (Zero potential) to discharge. If the Telecom Equipments are fed with positive the cloud will choose the low resistance tallest positively charged Antenna's to discharge, this could damage the entire setup of Telecom equipments. So the Telecom equipments are fed with Negative supply Voltage.
A telecom shelter contains transmitters inside.
To avoid the corrosion of the copper conductors under the ground.
It was originally supplied by a large bank of lead-acid batteries, 24 cells in series gave 48V.
because the termination and relays in side the telecoms penal needs for DC supply to continues the protection equipment and relay and purpose of telecoms
dc
Voltage is dependent on a reference. If I have a 12 volt battery, and ground the - side, it is 12 volts to ground. If I instead ground the + side, it is -12 volts to ground. -48 volt telecom equipment is simply referenced to ground "upside down" or backwards, giving it a negative sign.
There are many ways in which one can acquire telecom test equipment. This includes sites such as Amazon or eBay as well as specialist firms such as RS Online and Sunrise Telecom.
its operation and maintenance equipment
always think of any supply system so : RED = MOST POSITIVE BLACK = MOST NEGATIVE in a telecom system the -48V supply is refferenced to ground and earth, so the supply wire is NEGATIVE, this means a DC supply most positive signal the RED wire, go to EARTH = ZERO, the BLACK wire is the MOST negative, so in this case it is -48V
No, it will not work to interchange negative 48V with positive 48V directly as they have opposite polarities. This could damage the components or circuit connected to the power source. Proper precautions and circuitry must be used to convert or invert one voltage into the other.
In a 48V DC system you ground the positive to 0V so the live wire will be -48V.
This voltage is supplied by large banks of lead-acid batteries at the central office. There are 24 cells in each battery, giving 48 volts. Grounding the positive battery terminal makes the delivered voltage negative. Batteries are used so the system can keep operating (for a period of time) during a power failure, so that emergency and other important calls can still be made.
-48 volts is commonly used in telecommunications and data centers because it provides a stable power source for equipment while minimizing the risk of electric shock to humans. This voltage level also allows for efficient power distribution and reduces power loss over long distances in cables.
A 48V power source is used to power an SDH pump to allow for sufficient electricity to keep the motor moving at maximum efficiency. These pumps are used in a variety of agricultural and industrial applications.