Grounding
Grounding
(OP)
Hi Everybody,
Today I happened to have a word with a utility director and he gave me the value of 3 phase fault of 1000 A on 8.3 Kv line and 700 A ground fault. It surprised me, after finishing my engineering degree and since I have stepped in this engineering field( 1 yr exp.) and from what I have read, I have always read stories of ground fault current being limited to couple of amperes and those big issues of transformer grounding and to my surprise he tol me that their 230 KV/44 kV substation is solidly grounded. If this happenes, so where do we ground a transformer. I have these IEEE standards just providing exhaustive information about transformer grounding, where do we use it then. I dont work in this area but just casually came acroos while related to one of projects. Could you help me with this.
Thanks
Today I happened to have a word with a utility director and he gave me the value of 3 phase fault of 1000 A on 8.3 Kv line and 700 A ground fault. It surprised me, after finishing my engineering degree and since I have stepped in this engineering field( 1 yr exp.) and from what I have read, I have always read stories of ground fault current being limited to couple of amperes and those big issues of transformer grounding and to my surprise he tol me that their 230 KV/44 kV substation is solidly grounded. If this happenes, so where do we ground a transformer. I have these IEEE standards just providing exhaustive information about transformer grounding, where do we use it then. I dont work in this area but just casually came acroos while related to one of projects. Could you help me with this.
Thanks






RE: Grounding
Industrial systems are often impedance-grounded to limit fault current damage and hazards from ground faults.
The grounding method depends on the type of system, equipment involved and local custom.
RE: Grounding
What is the arrangement of the transformer, thus the vector-group of the transformer? Yd or Yy? If the secondary side is delta, how do you ground it? And if you say the substation is solidly grounded, to which side do you refer? Normally the primary side will be solidly grounded on that voltage range (230kV) This is because non-uniform insulation (insulation degraded towards neutral point) is used for a saving in cost - this is for 132kV and above. For the secondary side it depends - many older installation is still solidly grounded.
As a side note: Regulation (British) state that any low voltage system (between 50V and 1000V) must be solidly grounded.
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RE: Grounding
RE: Grounding
I hope this helps,