I think its around 42.9 or maybe 67.2? Not sure.
Maybe you need to rephrase your question? One thing to be mindful of when you do is that the IEEE and IEC defintions of open delta and broken delta are the opposites of one another. It's a world wide forum so clarity is required.
Regards
Marmite
If memory is correct, a 3 wire open delta bank only gives 57% of a load rating then that of a closed delta. Function wise its not worth the unrealized capacity and voltage imbalance when used for motors and 3 phase only loads.
When one transformer is lost in a delta bank and the bank is left in service in open an delta configuration, the capacity is about 58% of the capacity with three transformers.
Bill
--------------------
"Why not the best?"
Jimmy Carter