Transformer Frequent Fault
Transformer Frequent Fault
(OP)
we are dealing with Utility company recnetly. They provide 1 single transformer for a 4.16 kv SWGR. The sencondary of the transformer is direct buried. Based on IEEE, we designed our downstream protection according to infrequent fault of the transformer. But the Utility company insists on using frequent fault and asked us to speed up our protection. I don't see any point. Do they have different protection guideline ecxept IEEE?






RE: Transformer Frequent Fault
RE: Transformer Frequent Fault
If you can protect for the frequent fault damage curve, your transformer will be better protected and likely last longer regardless of how many faults it actually experiences, so why not do it if possible.
RE: Transformer Frequent Fault
Do faults close to a substation often take that long to clear?
RE: Transformer Frequent Fault
RE: Transformer Frequent Fault
Fault clearing time depends on the type of fault and fault magnitude. A bolted fault close to the substation should clear within a few cycles. A downed conductor could take much longer, but current will be less.
RE: Transformer Frequent Fault
RE: Transformer Frequent Fault
The IEEE Red Book or Buff Book would be really good resources for you and will explain why the transformer damage curve must be shifted when considering secondary line-to-ground faults and primary protection on a delta-wye transformer.