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Neutral earth is very necessary for observe the unbalaced laod of the 3 phase system. it is also useful for single phase supply and in lighting purpose. neutral earth is also earthed the short ciruit fauly current , which is flowing through neutral. this type it is very essencial for protection and safety purpose.
AnswerThere are a number of reasons why the neutral of a supply is earthed (grounded). The first reason is to protect the low-voltage secondary side of the distribution tranformer in the event of a short circuit from the high-voltage secondary side (it will cause the protection on the high-voltage side to disconnect the transformer). The second reason is to establish a datum point for potentials measured on the secondary side of the tranformers -in particular, if the star-point of a three-phase transformer is not earthed, then an unbalanced load will result in unbalanced supply phase voltages, and a potential-difference between neutral and earth -both undesirable and dangerous.
What else can I help you with?
What is an Earthed voltage transformer?
An earthing transformer provides a neutral in a delta connected system.
What is the star point of a CT?
The term, 'star point', refers to the common point of connection for the three windings of a star-connected (wye-connected) transformer connection. The star point is usually earthed (grounded) and provides the neutral point of the connection.
Why are low voltage electrical cables earthed and high voltage cables not in an electrical system?
The answer is more obvious if you use slightly different terminology to ask it. You could re-phrase the question as:Why are the low-voltage wires in a building earthed , but high-voltage transmission lines not?Wiring in a building or home that a person may come in contact with is earthed, or grounded for safety. If a live conductor in a grounded system comes in contact with an equipment frame or other metal object, fault current flows and trips the overcurrent device. If the building's wiring were not ground-referenced, you could have exposed live parts and not know it. Surprise!On the other hand, high-voltage transmission lines are optimized to transport electrical power long distances. Power transmission typically uses 3-phase delta which does not need an earth connection. The grounded conductor, or neutral, is derived locally after the distribution transformer. Overcurrent protection is for the protection of the lines themselves, not for people that might accidentally come in contact with them! This is why there are such strict rules concerning keeping us separated from the transmission lines.Keep in mind that the transmission towers themselves are grounded, and there is usually a grounded wire up top, but this does not form part of the transmission system, it is there for lightning protection.AnswerUnderground high-voltage cables are earthed.
Why the earthing pin of a socket in eletrical appliances is long and thick?
At very first the load to be EARTHED before polarities to protect the load and human being
How do you calculation of selecting Neutral Earthing Transformer?
iT IS ISMILAR TO THE GROUND RESITOR CALCULATION FOR TRANSFOMER THE TYPICAL EXAMPLE WAS ANSWERED EARLIER FOR TRANSFORMER DT.19-06-2009 Neutral of transformer can be grounded solidly earthed OR with Neutral Grounded with Resistance. Typical shunt calculations fro 5 MAV 11/6.6 kv transformer neutral are as :_ Transformer rating = 5 MVA Voltage ratio = 11/6.6 KV Vector Group = Dyn11 (6.6 KV ground through Resistor) During Earth fault voltage between Neutral & Earth = 6.6/√3 = 3.81 KV Earth Fault current will be limited to = 5 x 10³ /(√3 x 6.6) = 437.38Amp. N.G.R. value in ohm = V / I = (3.81 x 10³) / 437.38 = 8.71 Ohm Value of N.G.R. is 437.38 Amp, 8.71 Ohm., 10 Sec NGR are inserted On Higher voltage to restrict earth fault current BY SRI
Why neutral is earthed always?
The two wires carrying a standard ac power supply are the live and the neutral. By convention one of the two wires is earthed at the transformer providing the supply. That then becomes the neutral and the other wire is the live.
What is the power line voltage between phase and earthing?
It is the same as phase to neutral. As the neutral is earthed at the electricity suppliers transformer.
Where you have select unearthed cable?
Earthed cables shall be used wherever the syem Neutral grounding Solidly. Vise versa-Un earthed cable shall be used wherever the syem Neutral grounding through NER or Reactance.
What purpose do three prongs serve on an electrical plug?
One is live, one neutral, and one earthed.
When was Earthed to the Ground created?
Earthed to the Ground was created in 1984-05.
Why zero sequence current cannot flow through a star connected machine unless the neutral is grounded?
If the neutral point is not earthed than the zero sequence current will not have any return path.It will be an open circuit for the zero sequence circuit.
Can delta connection be used on 3 phase 4 wire system?
A delta connected appliance can be connected to a 3-phase system by leaving the neutral unconnected. The appliance must be properly earthed.
Why live and neutral wire essential for proper working of electrical circuit?
Two wires are always needed to supply electrical equipment so that the current has a complete circuit to flow in. One of the wires is earthed at the supply transformer, that one is called the neutral, and the other one is the live.
Why voltage at neutral in ckt is zero?
You really should be asking why the potential of neutral is zero. 'Voltage' means 'potential difference' which, by definition, cannot exist at at point. The reason is that the neutral conductor is earthed (grounded), and earth is, by general consent, considered to have a potential of zero volts. In practise, however, there is usually a small voltage drop between the neutral and earth, so it would be more accurate to say that the neutral's potential is close to zero.
Can insulator be earthed?
yes
What is the purpose of neutral contactor?
Presumably, you are asking the purpose of a neutral conductor, rather than 'contactor'?A alternating-current supply has two conductors, a lineconductor and a neutral conductor. The line conductor is at system potential (e.g. 230 V in Europe), whereas the neutral conductor is at approximately earth (ground) potential because it is earthed (grounded) at the supply transformer. The neutral conductor acts as the 'return' path to the transformer, carrying the same load current as the line conductor.
Why star point of star connected motor is not grounded?
Another AnswerA motor represents a balanced three-phase load and, therefore, there is no neutral current, so there is no requirement for a neutral connection. Regulations prevent an earth being used as return, so the star point shouldn't be earthed either.
