Arcing Ground

Q. What is arcing ground?

Ans: Arcing ground is a phenomenon which is observed in ungrounded 3 phase system. In an ungrounded system capacitance are formed between phase and ground. The voltage across this capacitance is phase voltage. During fault this voltage reduced to zero in faulted line where as in other phase increased by a factor of √3.

The arc between the faulty conductor and ground gets extinguished and restarts many times, this repeated initiation and extinction across the fault causes severe voltage oscillations of order nearly 3 to 4 times that of nominal voltage. This repeated arcing across the fault due to capacitance between the conductors and the ground is known as arcing grounds.

Q. How can eliminate is arcing ground?

Ans: Arcing ground can eliminate by using Arc suppression coil grounding also known as Peterson coil. Peterson coil is iron cored coil connected between neutral and ground which induces inductance in the circuit to neutralize capacitive fault current.

For explanation read Arcing grounding (explained)