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Neutral, by definition, is grounded at the distribution panel, and also at the distribution pole. That is how the hot to ground voltages are prevented from exceeding their normal voltage and encroaching on truly lethal voltages, such as 7.6kV in a typical US 13.2kV system, in a wye configuration.
Note: and this is critical, do not depend on the fact that neutral is grounded and consider that it is the same as protective earth ground. It is not. Protective earth ground is a different wire.
Wiki User
∙ 14y ago
Wiki User
∙ 10y agoThere is no such thing as a 'phase to neutral' fault. You are thinking of a 'line to neutral' fault. A line to neutral fault often occurs when the insulation between a line conductor and a neutral conductor breaks down and fails. This results in a short circuit which causes a large line current to flow and which should cause any overcurrent protection device to operate and disconnect the line.
Wiki User
∙ 13y agoIt means there is a current to ground which should not exist. A Ground Fault Circuit Interrupter (GFCI) is used to detect this ground current fault and to trip.
Wiki User
∙ 10y agowhen neutral short to earth
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Can you glow led by using neutral and earth?
If you connected neutral and earth (ground) to each lead in an LED and it glowed then this would be evidence of a ground fault.
Is a ground fault protection for equipment required even if the neutral will not be used?
Yes, ground fault protection for equipment is requiredeven if the neutral will not be used.However, the question implies that it might not be required if there is a neutral. That is not true. With two exceptions, ground fault protection is always required in the US, and it is probably required in other countries as well.The exceptions are the use of an electric cooking range, and an electric clothes dryer. In those cases, the US NEC allows the neutral conductor to also be the ground fault conductor, except for the case where the range or dryer is in a mobile home. In the case of the mobile home, the ground fault conductor and the neutral conductor must be maintained separate and distinct all the way back to the distribution panel.In every other case, including where local code overrides the US NEC's exceptions, it must be understood that ground fault protection (protective earth ground) is not the same as neutral, even though the neutral conductor is grounded.
What is ground fault in the NEC book?
A ground fault is where there is unexpected current on ground. It represents an imbalance between (hot) current supplied and (neutral, or opposing hot) current returned. That imbalance, by Thevanin's current law, must mean there is current on ground.Usually, a ground fault represents a malfunction or short in the load. Sometimes, it represents a cross tie or interchange of ground and neutral. In any case, a ground fault must be corrected, because it represents an unsafe condition, and because the NEC requires such correction.Some times this is a bit tricky to see, since neutral and ground are tied together at the distribution panel and at the service transformer. Since the NEC, however, requires isolation between ground and neutral except at the panel, detecting ground fault is somewhat straightforward, usually measured with a differential current transformer, comparing hot and neutral or opposing hot.I do not have a copy of the NEC in front of me. This is an intellectual answer, but I believe it to be consistent with the NEC's formal definition of a ground fault. Please, anyone with the formal definition, feel free to refine this answer.
Does voltage on ground mean open ground?
Voltage on ground can mean an open ground. It can also mean (high) current on ground, due to a ground fault such as reversed neutral and ground.
Why neatural ground resistor using in 33kv transformer?
The function of a neutral earth resistor is to limit any fault current resulting from fault between a line conductor and earth.
What happens if you wire a ground and neutral wire together in an outlet box?
If there is a GFCI in the circuit it will stop working correctly. They compare ground current to neutral current to detect a fault. It makes ground current equal to neutral current which is a fault condition.
What is a ground fault?
difference in current between hot and neutral conductors
What neutral ground resistor?
Neutral Ground Resistor is using for minimizing the fault current of system. It is a resistor which connected between ground and neutral and increase the resisting path for fault current.
Can you glow led by using neutral and earth?
If you connected neutral and earth (ground) to each lead in an LED and it glowed then this would be evidence of a ground fault.
Is a ground fault protection for equipment required even if the neutral will not be used?
Yes, ground fault protection for equipment is requiredeven if the neutral will not be used.However, the question implies that it might not be required if there is a neutral. That is not true. With two exceptions, ground fault protection is always required in the US, and it is probably required in other countries as well.The exceptions are the use of an electric cooking range, and an electric clothes dryer. In those cases, the US NEC allows the neutral conductor to also be the ground fault conductor, except for the case where the range or dryer is in a mobile home. In the case of the mobile home, the ground fault conductor and the neutral conductor must be maintained separate and distinct all the way back to the distribution panel.In every other case, including where local code overrides the US NEC's exceptions, it must be understood that ground fault protection (protective earth ground) is not the same as neutral, even though the neutral conductor is grounded.
What is meant by neutral grounding reactor?
Neutral-earthing reactors or Neutral grounding reactors are connected between the neutral of a power system and earth to limit the line-to-earth current to a desired value under system earth fault conditions.
Why no electric shock from neutral line?
There is normally no voltage on the neutral line because the neutral line is grounded. However, and this is always important, do not assume that neutral is grounded, nor that there is not an elevated voltage on neutral or ground due to a possible ground fault.
What is neutral grounding resistor panel?
A neutral grounding resistor panel is used to resist fault current to the ground. It is used for alternator protection protection purposes. When a fault occurs in the alternator, the panel helps force the current to the ground.
What is ground fault in the NEC book?
A ground fault is where there is unexpected current on ground. It represents an imbalance between (hot) current supplied and (neutral, or opposing hot) current returned. That imbalance, by Thevanin's current law, must mean there is current on ground.Usually, a ground fault represents a malfunction or short in the load. Sometimes, it represents a cross tie or interchange of ground and neutral. In any case, a ground fault must be corrected, because it represents an unsafe condition, and because the NEC requires such correction.Some times this is a bit tricky to see, since neutral and ground are tied together at the distribution panel and at the service transformer. Since the NEC, however, requires isolation between ground and neutral except at the panel, detecting ground fault is somewhat straightforward, usually measured with a differential current transformer, comparing hot and neutral or opposing hot.I do not have a copy of the NEC in front of me. This is an intellectual answer, but I believe it to be consistent with the NEC's formal definition of a ground fault. Please, anyone with the formal definition, feel free to refine this answer.
Does voltage on ground mean open ground?
Voltage on ground can mean an open ground. It can also mean (high) current on ground, due to a ground fault such as reversed neutral and ground.
What would cause 5 volts to be sensed at water supply pipe?
The water pipe is not properly grounded AND there is a ground fault or neutral imbalance in the house. Alternatively, there could be a neutral problem. In an ideally balanced house, the current on one hot leg balances the current on the other. This means that there is no current on neutral. In practice, there is some imbalance, and that common mode current does flow on neutral. If a circuit has a ground fault, the current return for that circuit is on ground, instead of neutral. That is wrong, and must be corrected. However - neutral and ground ARE connected together at the distribution panel. They are also connected at the street, so imbalance current could flow through ground instead of neutral. How much voltage is dependent on how much impedance. If there is a voltage at the house ground, and no ground fault or major imbalance, it calls into question the adequacy of the ground path, however, it is also possible that neutral is open, causing the imbalance current to flow through ground alone.
Is it advisable to use line to neutral power supply on a single phase residential area when the safety is concern?
line to line or line to neutral is the only way to use power line to ground if a FAULT current in the ground is a problem that needs to be corrected, an insulation fault
