Earth faulth protection in a ungrounded system
Earth faulth protection in a ungrounded system
(OP)
Hello everybody,
I have to adjust the relay settings in a ungrounded system at 13,2 kV, and I want to know if there is a stardard setting for 3V0 (using broken delta for the measurement) in the detection of ground faults. I think an adjustment at 0,1*Vnominal must be right considering that: in normal operation 3V0=0 and, in fault condition it would be 3*VLN.
Thanks in advance.
I have to adjust the relay settings in a ungrounded system at 13,2 kV, and I want to know if there is a stardard setting for 3V0 (using broken delta for the measurement) in the detection of ground faults. I think an adjustment at 0,1*Vnominal must be right considering that: in normal operation 3V0=0 and, in fault condition it would be 3*VLN.
Thanks in advance.
RE: Earth faulth protection in a ungrounded system
This is to ensure that 95% of the generator winding is protected.
RE: Earth faulth protection in a ungrounded system
Also, there needs to be a resistor across the open to pass third harmonic current.