can any body tell how to calculate the capacity (KVA) of a zig-zag grounding transformer ,we are using this to provide ground fault path to 33 KV delta system ,we want to use the secondary of this Tr for Aux load(33KV/415V)
What's the earth fault current?
Is there a neutral earthing resistor?
How long will an earth fault be allowed to stay on the system?
What KVA do you need for your auxiliaries?
The zigzag configuration is only use to protect ungrounded side of power transformer. The capacities it is depend on the load that will be connect to this transformer, because with this kind you have the point of earthing and auxiliary power supply.
Our client mentioned there may be impedance issue with Zig-zag transformer. I don't really understand this. Can somebody here shed me some lights on me?