We don't have to supply anything customer wants, it's not a good engineering practice.
Because I think the transformer is to small to have a differential protection. I never saw transformer less than 10 MVA to have differential protection
I don't think any international standard says differential protection for specific transformer size.
In various projects, we never used differential protection for transformers below 5 MVA. For a 2.5 MVA transformer, standard protections + 'REF',at best, should suffice.
Infact, customer, needs to be told about "cost of protection equipment" v/s "cost of equipment to be protected". However, if customer still insists for 87T, go ahead as suggested by Tornado.
Differential Protection for Transformer
Re: Differential Protection for Transformer
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