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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

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Q: How do you wire -48v dc power and ground to earth?
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How do you get -48v DC?

In a 48V DC system you ground the positive to 0V so the live wire will be -48V.


Why use -48V dc in bts?

-48 v is given to BTS because in this voltage Noise generation is minimum. Because two terminal comes out from the battery and through red color wire we ground the +ive terminal so that possibility of noise interference will get zero because noise occurs only in the +ive terminal that's why we use -ive voltage in the BTS.


Why is a rectifier needed for a GSM BTS?

This is bcoz we need -48V for Gsm BTS, -48 DC is used to control Fluctuation So the main function of this is 1) To convert AC to DC 2) To control overloading


Why DC is preferred in telecom industry?

One main advantage is that it is easier, cheaper, and more efficient to battery back the system. -48V DC can be made simply of 4 12V batteries (think giant car batteries) in series. The string looks like this: AC POWER --> RECTIFIER --> BATTERIES --> DC LOAD To battery back an AC system you have this string. AC POWER --> RECTIFIER --> BATTERIES --> INVERTER --> AC LOAD (which is usually converted back to DC by the equipment's power supply to run the electronics). No step in this process is 100% efficient, and every part costs $$. DC eliminates a lot of these steps. This is not to say that everything in a Central Office is DC powered -- they still have Air Conditioning, Lights, convenience outlets, etc -- but if you're ever in a Central Office when the power goes out, those things turn off until the generator kicks on and the transfer switch swings. Also -- doing things with Low Voltage (-48V) does have some EXPENSIVE costs associated with it. COPPER power runs are very expensive because of the low voltage used (-48VDC) -- it takes more than twice as much copper to feed the same Wattage/Amperage as a 120V supply. A=V*W W=V/A V=W/A The simplest rating on a wire is how many A it can draw for how many feet (there are other ratings, such as maximum voltage, but most of these approach 600V, so don't apply to this comparison). Most of these additional costs are one-time costs and therefore are justifiable.


What is a multiply contact relay?

It is a type of relay used to read the status of Breakers as well as isolators in scada system. As RTU operates at a voltage of 48V and Control panel operates at 110v inoredr to differentiate these potentials it is used

Related questions

How do you get -48v DC?

In a 48V DC system you ground the positive to 0V so the live wire will be -48V.


Is phantom power always 48v?

"Phantom Power" in use in the recording industry is ALWAYS 48V. Some types of mics use other types of power like T-power or an internal battery, but this is not "Phantom Power".


Why plus 48V not use in telecoms?

To avoid the corrosion of the copper conductors under the ground.


Why you use 48V for sdh?

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.


Why the bts is given a power supply of -48v?

because in this voltage harmonics are not present


Why won't my condenser mic work on logic pro?

condenser mics need 48V phantom power, make sure that the 48v is on, then check to see if the R is on and the I is on on your channel and see if they are wired to the master output.


Why -48 volts is used in electronics?

-48V is used in the telecommunication equipment. The source of the -48V is a bank backup batteries that are always kept charged in the event of power loss. The typical range of voltage is -36V to -60V in this application. Why negative voltage is used is probably tradition as the modern power supplies that use this voltage are isolated and run the same as long as the positive terminal is 48V above the negative terminal.


Will it works if negative 48V is interchange from positive 48V?

If it's a motor, it may just run backwards. If it uses any kind of solid-state electronics, you will very, very, very likely blow the equipment or the power supply. Reversing polarity of power supplies? Just don't do it.


How is -48V possible in telecomm equipment?

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.


Can you charge 48v batteries with a 36v output charger?

No.


Why telecom power supply has 48V dc power supply?

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


Can you convert ATX power supply to run off DC input 24v 48v or 120v?

Like to run on a DC powered machine? Probably the easiest and safest way would be to buy a standard power inverter.