How grounding resistor and reactor have no effect in 3 phase fault?

Thread starter Manoj Sahu
Start date May 12, 2017
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3 phase Fault Grounding Phase Reactor Resistor

In summary, grounding resistors and reactors are not directly affected by 3 phase faults and cannot be used to prevent them. They are designed to mitigate ground faults, which do not occur in 3 phase faults. They are not necessary in a 3 phase system, as the likelihood of a ground fault is low. In some cases, they may be used to limit fault current in single-phase or two-phase faults in a 3 phase system, but are not needed in a 3 phase fault where all three phases are involved.

May 12, 2017

Manoj Sahu

How would you justify the above question? Please elaborate in detail with diagrams (if applicable). It will be really helpful. Thank you.

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May 12, 2017

anorlunda

Staff Emeritus

Insights Author

Hint, If you have a wye connection with the center point grounded, what current flows to ground?

1. How do grounding resistors and reactors affect 3 phase faults?

Grounding resistors and reactors do not have any direct impact on 3 phase faults. They are used to limit the flow of fault current in the event of a ground fault, which can occur in single-phase or two-phase faults. In a 3 phase fault, all three phases are involved and there is no ground fault, so the grounding resistors and reactors do not come into play.

2. Can grounding resistors and reactors be used to prevent 3 phase faults?

No, grounding resistors and reactors are not designed to prevent 3 phase faults. They are used to mitigate the effects of ground faults, but they do not have any effect on 3 phase faults.

3. Why are grounding resistors and reactors not effective in 3 phase faults?

Grounding resistors and reactors are not effective in 3 phase faults because they are designed to operate in the event of a ground fault, which does not occur in a 3 phase fault. They do not have any impact on the fault current flow in a 3 phase fault.

4. Are grounding resistors and reactors necessary in a 3 phase system?

No, grounding resistors and reactors are not necessary in a 3 phase system. They are only used in systems where ground faults may occur, such as single-phase or two-phase systems. In a 3 phase system, the likelihood of a ground fault is very low, so grounding resistors and reactors are not needed.

5. What is the purpose of grounding resistors and reactors in a 3 phase system?

Grounding resistors and reactors are usually not used in 3 phase systems. However, in some cases, they may be used to limit the fault current in the event of a single-phase or two-phase fault, which can occur in 3 phase systems. But in a 3 phase fault, where all three phases are involved, they have no effect and are not necessary.