Understanding an Open-Delta Bank
I don't know where else to ask this question and I have been trying to find the answer for a while now(no one seems to know for sure).
I am an apprentice lineman for my local utility company and I'm trying to understand how an open delta bank provides TRUE three phase power.
A regular wye or closed delta bank has three transformers with three phases feeding the primary side, 3 phases in 3 phases out(3 different phase angles).An open delta only has two transformers with two primary feeds.2 phases in 3 out?I don't get it.
Is an open delta bank secondary supplying true three phase power(120 degree phase shift)or is it two phases compensating for the lack of a third.
Just wondering if I am far off track on my thinking...
Any information is appreciated.