There are 3 rules that need to be adhered to when paralleling transformers. 1: Must have the same voltage ratings 2: Must observe proper polarity 3: Must have the same percent impedance. This video explains how to match the polarities.
Regardless to the other conditions for making parallel operating could be applicable or happening , we must bring same transformer brand or this will not affect or we not taking in consideration for parallel tr. Operation?
This is a bit confusing talking + and - when we are talking AC. I don't really see how we can find out which terminals are which. Is there a real world example video somewhere of someone showing how they work out which terminals are which?
Been looking at this lately. Problem is when wires are unmarked. Apparently, the rule that Primaries determine secondary phasing means the most important connection is to ensure the secondaries are in phase: Dot Convention. Out of phase is noticeable (light bulb, analog meter) because the opposite phase cancels. I'm not certain, still learning and about to try it on 2 of the same xfmrs at reduced voltage/current. I will post result for future readers.
