A) If low resistance configuration is chosen, then, ground fault current is greater than 25% of 3-phase value.
B) If high resistance configuration is chosen, then, ground fault current is between 1 to 5% of 3-phase value.
C) Ground fault protection scheme is important because affects resistor thermal rating, hence size.
D) For B) above, ground fault current must not be less than system charging current produced by phase to ground capacitance in 11 kV system.
E) For D) above, total capacitance calculation must include line to ground capacitance of cables, motors, Transformers, and (often forgotten) surge protection capacitors, as well as lightning arrestors. shirish prajapati
The Neutral is grounded so that any of the phase conductors that contact a ground will short the circuit and trip your over current protection. If the neutral wasn't grounded, it would be possible for a grounded surface to become energized without blowing the circuit. Also, grounding the neutral in a 3 phase system helps stabilize phase voltages. A non-grounded neutral is sometimes refered to as a "floating neutral" and has a few limited applications.
As a side note, the neutral should NEVER be connected to a ground except at the point at the service where the neutral is initially grounded. This can set up the ground as a path for current to travel back to the service. Any break in the ground path would then expose a voltage potential.
They are two things all together different.
It is the name of the three wires in a domestic single-phase power supply, otherwise known as live, neutral, earth.
The grounding of a neutral is the process of doing the action of grounding. When the installation is complete the statement can be made that the neutral is then grounded.
Neutral is vital to complete the cicuit. Ground is vital to carry the current to earth during a malfuntion of the appliance using power to drive it, should the current come in contact with the frame or outer covering of the appliance and endangering the users life.
Grounding of I and C? to ground something is to have a wire that goes to a grounded connection the bare wire in a normal wire set.
Electrolyte plates in a grounding system are electrically grounded metal plates on which a person stands to discharge static electricity picked up by his body. This is called grounding.
Reactance grounding is done to lower ground fault current amounts, often to protect generators. It's done by tying the neutral of a generator to a grounding reactor (the other side of the reactor is tied to ground).
The neutral is a current-carrying conductor, the grounding wire is not; it is for safety as an ALTERNATE path to ground. For example, if something happens to disconnect the neutral or if the hot side comes into contact with conductive portions of an appliance, the grounding conductor can save a life by providing a safe fault mechanism.
The grounded conductor (Neutral) can be white or gray. The grounding conductor can be solid green, Green with a yellow tracer or bare copper.
You can use resistance or reactance grounding on generators and motors. My understanding is resistance grounding is often used to limit ground fault currents to a few amperes, while reactance grounding will limit fault current to less than the three phase fault current. If reactance grounding is used to limit fault current o very little (like resistance grounding), transient overvoltage problems can occur.
Depends on what your grounded for...
The question doesn't provide enough detail to give a definitive answer. The neutral PD is often used in protective functions on high resistance grounded generators (when grounded through a transformer). High resistance grounding limits the use of transformers - you must be using balanced loads, since very little current will flow (typically around 5-20amperes max) to the neutral. Because of this, phase to neutral values (such as voltage) are meaningless. Any current flowing in the neutral will cause an offset in all three phases from neutral. Since the neutral is high resistance grounded, it does not take a significant amount of current to cause significant offset.
Neutral mean is zero potential and neutral wire it has been taken from the Distribution Transformer " Y " point (Xo). This point " Xo " is directly grounded through the dedicated grounding system.
In house wiring it's typically a bare copper wire. It may occasionally be green.
A bare grounded neutral should never get close to the ground if it is wired properly. When the neutral leaves the meter base it is in conduit and should enter into the distribution panel where it connects to the neutral buss. It is at this junction that the copper ground wire is connected after coming from the outside ground rod or ground plate which ever grounding system was used.
Neutral is vital to complete the cicuit. Ground is vital to carry the current to earth during a malfuntion of the appliance using power to drive it, should the current come in contact with the frame or outer covering of the appliance and endangering the users life.
Answer for USA, Canada and countries running a 60 Hertz supply service.There is only one place that the neutral can be grounded and that is at the service distribution box that containing the first over current device. You have the neutral coming into the box and the ground wire going to either a grounding rod or the water line where it comes into the house.
If two ungrounded (hot) conductors touch or an ungrounded and a grounded (neutral) conductor accidentally touch, it is called a short or short circuit. If an ungrounded or a grounded conductor touch an equipment grounding conductor, it is called a ground fault.
In residential 120 VAC, single-phase electrical wiring, there are three main types of electrical wires: 1. Ungrounded conductor (Hot, and sometimes called "Line" or "Phase") 2. Grounded conductor (Neutral), and 3. Grounding conductor (Safety Ground or Protective Earth) The groundED conductor is the power return, intended as a current return path from the load back to the source to complete the "circuit." Its insulation is White, gray or a non-green color with white stripes. The National Electric Code requires it be connected to earth ("groundED ") at the service entrance and usually only there. The groundING conductor is usually the safety ground which serves as an emergency current return path in the event of a circuit fault or overvoltage. Like the groundED conductor, it too is grounded at the service entrance, but is also connected to metal surfaces and parts along the circuit, groundING them. It conducts current only if the current "seeks" to return to the service entrance along a path other than the Neutral (like through your chest, should a Hot wire becomes loose and contact metal in the circuit that you may touch). Since the grounding conductor doesn't normally carry current, its cross-section is sometimes smaller than the groundED conductor's. The grounding conductor's insulation is green (no other conductors can have green insulation) though sometimes it is bare copper. Sometimes the steel metal conduit enclosing the Hot and Neutral acts as the grounding conductor.
The real purpose of neutral is grounding. In order for electricity to flow you need a direct continuous link from the supply to a ground. Without the neutral electricity wouldn't be able to flow because it wouldn't have a ground (a place to go). The real name for neutral is the grounded conductor, and what is commonly referred to as ground is really the grounding conductor. The grounding conductor exists for the sole purpose of being a back up neutral in case something happens, this way you don't BECOME the ground if you touch it. But don't think that means you can go touching wires if you don't know what your doing cause you can still get hurt even with both grounded and grounding hooked up.