earth fault protection in delta networks
earth fault protection in delta networks
(OP)
G'Day,
We have a power system with a grounded neutral. The distribution to various loads are in delta and there is no neutral. when there is a ground fault on this distribution system the REF protection relay of the generating station trips. Although we have Over current earth fault system on the distribution feeders the fault passes through and both the relays trips.
is there any necessity to provide the earthing transformer to the system and provide REF protection in the distribution network.
Please advise
We have a power system with a grounded neutral. The distribution to various loads are in delta and there is no neutral. when there is a ground fault on this distribution system the REF protection relay of the generating station trips. Although we have Over current earth fault system on the distribution feeders the fault passes through and both the relays trips.
is there any necessity to provide the earthing transformer to the system and provide REF protection in the distribution network.
Please advise





RE: earth fault protection in delta networks
The system is already grounded, you do not need earthing protection. Although your system description is not very clear to me.
Rafiq Bulsara
http://www.srengineersct.com
RE: earth fault protection in delta networks
RE: earth fault protection in delta networks
Is this a transformer or generator protection that you have?
More detail is needed. ratings, voltage levels, how many units, island system or not...
rasevskii
RE: earth fault protection in delta networks
REF should trip for internal fault only and not external fault. Check for polarity of CT and / or relay circuits / wiring. Is there nay time delay on REF what model it is? Does it have any instantaneous element that is tripping?
NC
RE: earth fault protection in delta networks
Rafiq Bulsara
http://www.srengineersct.com